Friday, 21 December 2018

VHF Sporadic E when you least expect it.

It is sunset here as I write this - today sunset is at 15:36. Only seven hours of daylight today, with the Sun rising at 08:37. Not exactly the type of day one might associate with Sporadic E. Yet I am reporting on a really good Es opening the day before yesterday, the 19th of December.

This is my second post today, the other one is here

In the midst of being on the lookout for December meteor showers it is easy to overlook seasonal Es. The same applies in early January. The things to look out for are when your MSK144 graph fills with a single strong station. Watching 10m is another trick, which is how I found it (thanks to Jaap, PA0O, whose 10m WSPR drew my attention to it). Then again one could watch DX Maps, PSK reporter or set up alerts on your phone with EsSense.
PSK reporter showing 15 minutes of 6m Es on 19 December 2018. Note that was already dark at ground level.
Or maybe just listen for it ...

There is often Winter Es about at this time of year, which is frequently wrongly called "Christmas Es". That name tends to makes people look at the wrong time. It could happen during my annual appearance on the RSGB Christmas Cumulative contest, but it never does. Not yet anyway. Sometime between early December and mid January seems to be the time. You just do not know exactly when or how often. It is usually a middle of the day thing, so having it in the dark is a bit unusual.

The opening here lasted two hours and 40 minutes, and I worked 36 QSOs, 22 squares, and 8 DXCC in that time. Plus I had a contact with Dale MM0INH at the end, when we tried to express how tired we were using the few characters you get in the FT8 mode.
6m Es contacts at GM4FVM on 19 December. The guy due South thinks he is at the South Pole (he isn't).
9A3ST (JN75) looks like the best DX at 1652km.

Great fun, totally unpredictable. All we need now is an aurora and a strong tropo opening and Christmas is complete (well, unless I get any "Co-op for Men" that is).

This says to me that the 50MHz band is a key part of my all-round VHF activity. I do find it a bit "easy", but then again not when I am pushing for DX. However, when I am putting together a year-round schedule of things to do, 6m has a habit of surprising me (in a nice way).

Simple antennas are very effective on 6m. Wire dipoles, crossed dipoles, HB9CVs, and verticals can all play their part. I was still using only 50W or so from the IC-7100. Being around at the right time is always important.

I did not do much on 4m during this opening, and I find that Winter Es rarely reaches 70MHz. However, I did hear a German station on FT8, but just long enough for one decode. 10m was also quiet, perhaps because activity is low. This is especially true on the WSPR mode which I use so much. I am beginning to think that WSPR is doomed, which is a pity given its ability to make antenna comparisons and run all night. I will not give up on WSPR in a hurry because I think that it still has relevance.

Anyway, that is amateur radio. Like life, you just never know what is around the corner.

Perhaps that is just as well.




The etiquette of a meteor scatter contact

I have a couple of postings nearly ready so this one should be quickly followed by another. Nevertheless, there are some things I want to get on record before we move on. These are about how we make meteor scatter QSOs, not about the data mode technology or the science of the meteors themselves.

First of all though, as it is nearly Christmas, I have to clear up some doubts amongst you all about what to buy me for a present. It is customary to give some manly scent at this time of year, but the one I use is not available in most shops because it is, of course, a designer label. Not for me (the man who has everything) something common to the parfumiers of Paris. No, coming in a subtle plain grey tin, is my "Co-op for Men". It will only cost you £1.00 for a 250ml spray, available via the exclusive Co-operative Wholesale Society of Manchester (branches all over the UK). Do I have sophisticated tastes, or what? Plain postage will do, no need to send it "signed for".'

Moving swiftly on, I know that some beginners on MSK144 and meteor scatter are flummoxed by the strange way contacts are carried out. It is not easy to know where to beam. Also, the long gaps in the QSO when nothing appears to be happening can be confusing.

As for beam angle, WSJT-X's meteor scatter solution, MSK144, offers two suggested beam directions when you put in a callsign and locator. These are "Az", the true direction, and "B", which is a suggested direction (sometimes B is called a "Hot bearing", which I thought was when the wheels fell off your Morris Minor). In theory the true direction will not work at all. Beaming directly at the station should produce no result as the meteor trail will block the direct path. In practice this is not quite true, but there are still better results to be had by beaming slightly off the true angle.

The angle WSJT-X suggests will provide a path to one side, and the relative deviation suggested to the other station should have you both pointing to the optimum point in the sky for communication. The reality is that my beams are not very gainy so they are wider than perhaps the designers of WSJT expect. So for me, a smaller correction seems to suit better. I generally take the true angle and add some correction up to about half that suggested. However, I always correct on the same side of the true as the "B" angle suggests so that we both point on the correct side of the true path.

Note that the deviation suggested will depend on the distance to be worked. So the two stations I worked along the same true beam heading in my last post, the Drammen Radio Society, LA2D, in JO59 (522km) suggested a deviation of 14 degrees north of true (Az54, B40), while Jukka, OH6UW in KP22 (1742km) had a suggested deviation of only 10 degrees north (Az54, B44). Other factors come in, but generally the further away the smaller the deviation. The less directional you antenna is, the less this matters. For a short yagi you can pretty well forget about it.

The other oddity for someone trying MSK for the first time are the rather un-nerving silent gaps between decodes. Because the meteors are often sporadic, you might transmit for 5 or 10 minutes before the station at the other end hears you. This is understandable (not everybody is as good an operator as you) but then there might be another 5 or 10 minutes before you hear their reply. So there is a variable wait to get the reply, during which you do not know whether to  keep sending, give up and try to work somebody else, go and have a cup of tea and a fig roll, or abandon meteor scatter entirely. My advice is to keep sending for as long as you can without overheating your equipment.

How difficult this can become depends on whether you are operating during a strong meteor shower or looking for "random" meteors at any other time of the year. During a major shower things work like an FT8 contact, you get the reply immediately and every signal is long and  strong so you feel comfortable. But when the shower slackens off you have long gaps of unpredictable duration. This adds to a joyous period of expectation during the quiet periods.

Take yesterday ... I heard that German stations had now got access to 4m again. So I went to 70.174 to call CQ. I heard from DK2EA and we exchanged reports. I never heard his RRR and the next decode I got from him was him working  G0CHE. At the same time OH3XF in KP10 called me. At this stage I do not know if DK2EA has received my report. He may have replied or not, I may have missed his reply, and he has gone on to work G0CHE. As clearly he now is doing something else, I decided to turn my beam to OH3XF instead.

After exchanging reports with OH3XF I heard him sending 73. At this stage many stop, but I decided to sent 73 three times to show OH3XF that I have heard him. In theory this could go on for ever, as not hearing anything might mean that OH3XF has stopped, or just that the meteors are not falling at this right moments and he is still trying to send me 73. There is no positive way to know.

After that, having sent 73 three times I went back to DK2EA and tried to finish that QSO (which might be finished anyway). I then received DK2EA sending CQ twice, but he did not reply - or I din't hear him reply.
GM4FVM trying to work DK2EA but succeeding with OH3XF
Frustrating? I do not know for sure that I worked DK2EA, but the fact that he did not come back to me later suggests that I did.  I did work OH3XF, (KP10, 1575km), a nice bit of DX. He replied to my CQ, and it took me about 5 minutes for me to get that reply, during which time I had started a QSO with another station. This is not unusual. You then have to decide which one to work (or try both, as some stations do, sending messages alternately). Most people just go for the best DX.

So it can get confusing. This variable 5 to 10 minute gap can mean that it is 20 minutes before you get a reply to your call, during which time you are feeling a bit on edge. The better the DX, the longer you are likely to wait. Some random contacts can last for hours if you have the patience, but the message is not to give up.

During all the time I was working OH3XF I could easily have received a further message from DK2EA (I didn't, which suggests he was beaming somewhere else by then). Anyone can call you at any time, they having heard your CQ of 30 minutes ago. This requires you to be flexible and ready for anything.

The QSO with OH3XF was quite quick at 4 minutes 15 seconds after I heard him, but I do not know which of my CQs he was replying to. Depending on which one of 18 CQs sent by me over  a period of 9 minutes, it was a total of 9 minutes or 18 minutes or probably somewhere in between.

For comparison, I had a QSO with DF5VAE, Charly, (JO64, 1004km) on 2m on 12 December. I saw a CQ from him and replied and the whole QSO took 18 minutes and 30 seconds. I waited 12 minutes and 30 seconds between hearing his report and receiving his confirmation that he had got mine, during which time I was sending him my report every 15 seconds. Charly emailed me with a very nice message - it turned out that he had called me after an earlier decode but it had only been one way at that time. You just never know ...

Remember, if you hear someone replying to your CQ of 30 minutes ago then they have been calling you for 30 minutes, i.e. 60 times. They must want to work you!

Despite all this complication, during meteor showers most QSOs are fairly quick and easy. It is only nutters like me who love random CQs who plod on for hours flogging lost causes. Many times I have sent a report and waited ages for a reply, even sometimes seeing the DX station working someone else in the meantime. I hope that when they do eventually see my message they will reply to it - and they usually do. If we have exchanged reports they can feel free to work somebody else while I send RRR, provided of course they reply to me once they do eventually get my signal. And persistence often works.

I say I like random meteor scatter, working outside the showers. I also like random QSOs, not involving skeds. Sure, I can do individual skeds and I welcome anyone who want to set one up. What I do not do is use chat rooms to organise my QSOs. There is one, KST Chat, which many use. I do not use KST. I find that people use it to avoid listening on the bands. Sure there are good folks (don't write in to say you are one of these good ones) who use it to advance their activity. Many others simply use KST to avoid having to listen and thus avoid doing the work of an amateur. They prefer to chat about irrelevancies and repel all newcomers to KST. It isn't what I want to do, but they can do what they please. It is a free world, or at least it is supposed to be a free world.

I find that those who claim this to be a free world, or a free country, often use the expression to avoid responsibility. With the privilege of an amateur radio licence comes some responsibility to other amateurs. It helps to actually listen to the radio. If your head is up your rear end on a chat room you don't hear very much (unless you do it with headphones on of course).

I just do not like chat rooms. Now we have network radio for setting up skeds, and that seems like a nice radio-alike way of doing it. Chat rooms seem to take the amateur's attention away from the radio and into the world of Narnia. But fine, off you go, nobody is stopping you. Just do not write to me to complain because I do not like KST. It doesn't mean I do not love you as a person, it means I do not use chat rooms.

OK, meteor scatter is daunting for the beginner. I cannot deny that long and worrying silences, strange beam headings, odd spells of heavy activity with weeks of seemingly nothing, uncertainly about who you are working and if you are finished, a distinct lack of 73s, plus lots more, seems to be a long list of off-putting peculiarities. However, it is very rewarding. Just imagine sending a signal and waiting in hope for ten minutes for a reply, which might come right now or later. Then ages later, out of the blue, some DX appears. Delayed gratification - just what we hair shirts love.

On the 6 metre band, at least, you can operate for a lot of time as if you are on a "conventional" mode.

Finally, it helps to set up a separate WSTJ-X "configuration" for MSK with longer watchdog times and so forth, and I hope to cover that at some stage too.

Speak soon (I'm usually on Echolink).




Tuesday, 18 December 2018

Geminids gone but there is still time for a month of action

The 2018 Geminids were pretty good from my point of view...
Meteor scatter contacts at GM4FVM 8 to 14 December 2018
Click to enlarge the image, if need be.

The image shows all three bands I used, 6m, 4m and 2m. Several of these people I have worked during various showers over the past 10 years. Some surprises this year included SM5EPO, at huge strength, on 2 metres. I have worked Per-O 14 times before during meteor showers, but previously only on 6m. SP9HWY was my 27th MS contact with Jurek on 4m, but needless to say many of those were random contacts outside any particular shower peak.

It was nice to work OH6UW on 144MHz after a gap of almost 5 years. I think that pretty well represents the different nature of 2m meteor scatter - it is more irregular in my experience. Just to prove myself wrong, I have worked YL2AO on 2m in the Geminids shower each year for the past three years. S52OR's record with me on various showers on 4m goes back to 2014.

IV3GTH was a nice contact on 2metres. OK, I have worked that part of Italy before on meteor scatter but it still never fails to amaze me that this is possible. He heard me calling CQ while I was beaming much further East. I saw him post that on PSK Reporter and I thought I might as well beam towards IV3GTH and call CQ. Much to my amazement he came back to me and then the contact started in earnest. He did peel off for a while to call another station in a much more attractive square than mine (I don't operate from an oil rig in the middle of the North Sea), but he came back to me later and we completed a nice QSO.

That contact proves how useful it is to tick the "Enable PSK Reporter Spotting" in WSJT-X. You never know who is watching PSK Reporter and may call you if they only knew you were there.

I asked before, why not try meteor scatter (here)? The same considerations still apply. If you can operate FT8 on VHF you have a station capable of working during meteor showers. The commonly held idea is that MS requires high power and big antennas but this is really no longer valid. The WSJT-X suite put paid to most of that. Of course, more power (how much? Just more...) might help, and so might a huge antenna. This year on 6m I have been using a two element HB9CV and about 55 watts. Not exactly earth shattering, but perfectly suitable.
6m HB9CV in use at GM4FVM ready for the windy season.

The eleven tips I give in the posting I linked to above are still valid. David, GM4JJJ added a twelfth. After listening on the bands this year I would just mention again some things worth remembering.

Please stick to the protocol for calling in the right segment in the right direction. Broadly speaking, if you are beaming South and East always use the second segment (don't check the "Tx even/1st" box on WSJT-X). If you are beaming West or North DO click the "Tx even/1st" box. Obviously, if the best DX in the world turns up on the "wrong" segment nobody will mind if you work them, but remember that while you do so you are probably wiping out all the receivers of all the stations around you. So be quick.

Best plan is - only call CQ on the correct segment (point 2 in that article). And don't waste everybody's time by calling stations who are calling in the wrong segment because they are almost certainly beaming away from you and are not interested in working you (point 3).

I know it is difficult to stick to this, and it is difficult to avoid making a mistake by clicking on a station in WSJT-X to reply to them before realising this would put you on the wrong segment. We are all understanding. We all make mistakes ourselves. But please don't just ignore the protocol. Try to stick to it.

Nor should this put anybody off. We all have to learn and newcomers will be treated with respect. Probably.

Do not imagine that high power is always needed. I was amazed to watch MI6XZZ working YL2AO with just 10 watts on 2 metres. I rather wondered if that was going to be possible. When I saw the reports exchanged and YL2AO sending RRR I realised that my doubts had been misplaced. Certainly 50 watts is fairly comfortable on 6m, and 200W is just fine as far as I can see. Many of the stations at the other end will be using 1000W and big antennas but meteor scatter is not a weak signal mode. During a peak the signals are remarkable strong. What you are doing by improving your antenna or using more power is to extend the length of time a signal can be heard at the other end while the meteor tail fades. Thankfully, MSK144 is very good at decoding very short signals, so it can pull messages out of very short pings.

And finally, operating on meteor scatter has informed my thinking on what constitutes a QSO. When every second counts you cannot stand on ceremony. All those 73s in the WSJT box of tricks are all very polite, but they are not strictly necessary. During meteor showers, and to some extent during auroras, the 73 is something not everybody waits for. They may not even send them. Did you get the callsign and report? If the answer is yes, you can fill in a QSL card, and exactly what else do you need? A "roger" from the other end certainly proves it, but so does the QSL saying he got it. I wait for the "roger". Do I wait for 73? Sure, for a while. But  do not think a QSO is invalid without 73s, and the arrival of the QSL card or other confirmation is enough for most meteor scatter operators. For most of us, seeing the other station calling CQ after we have all the other details is all the confirmation we need. A meteor shower only lasts a day or two so nobody stands on ceremony.

I was driven to write the above paragraph after reading quite a few snarky remarks on people's QRZ page along the lines of "If I didn't get your 73 you are not in my log". Well bully for you. I try to live in the real world. I love friendly expressions of good will but I don't penalise people for moving on to work some more DX.

So why not get out there and try? Meteor scatter is particularly accessible on 6m, and that HB9CV of mine is probably the minimum most people have. Even that log periodic you put up never thinking about meteor scatter would do. It isn't even the motorcycling season, so no excuses like that. Barefoot from a commercial transceiver (say 50 watts or so) should get some results on 6m or 4m. If you only have a low power licence it is still worth trying though you might have to pick strong signals to reply to. Especially on 2m, where long Yagis are narrower in beamwidth, you may have to pick your targets rather than call CQ. So listen first and see how others are doing it. Then just have a go..

A vertical or a dipole antenna may work on 6m but may not be so well liked by your amateur neighbours. If you use a vertical or dipole, stick to the same transmitting segment as the others around you or you will not be appreciated.

Really, anyone who can use FT8 can try MSK144. For this season, we have the Quadrantids shower to come. It peaks around 3 January. It is a broad shower so a week on either side can be productive, and that brings us close to the Ursids too. The Ursids are not very strong but occur on and around December 22. So the period between now and mid-January can be quite good, and it is often worth trying outside the shower peak during this time. Weekends are usually better, morning or late evening may be best. That would be best, but anytime is good. A modest antenna should bring stations 1000 to 1500km within range, with 2000km being about the maximum theoretically possible.

After mid-January there is usually a lull until April with just random meteor activity which falls to pretty low level in February and March. So now is the time to get going. Why not?




Tuesday, 11 December 2018

WSJT-X 2.0.0 is here

The new version of WSJT-X released yesterday introduces new functions and makes various improvements, including making the WSPR decoder more sensitive.

You can find it here

Please note that I directed everyone to the WSJT Homepage because of course you will not just want to download the suite itself but YOU WILL WANT TO READ THE NEW USER GUIDE before you use WSJT-X 2.0.0.

You will read the user guide, won't you?

Ah. Go on, go on.

Don't be like the two dunderheads I heard discussing this subject recently without the benefit of having read any guidance. I am not so good at reading these things myself but I have learned by experience - everything you need to know is in the guidance and most things people tell you about WSJT-X are wrong.

No need to believe me either, just read the guide.

I think we can take it that Joe Taylor and his team know more about this than I do.

As the latest versions of FT8 and MSK144 are not backwards compatible, the advice is to change over to the new versions now and encourage everyone to change over by the end of December at the latest. So please do that.

Nice to see that the Scottish MSK144 community are already on the right path (though it seems we still have to accept the frequency everybody uses and regard the band plan as advisory) ...

Good to see the new mode being used.

There have been warnings about this impending change-over for months now so we cannot say that we were not aware of it. I do not promote general use of release candidate versions on this site, but there have been 5 successive limited release trial versions to iron out the bugs. I do not encourage general users to download these trial versions after problems with earlier ones escaping into general use. Now that we have the "General Availability" version, off we all can go.

I have (probably forlorn) hopes that, as this upgrade answers all the issues of the meteor scatter community about contest working etc., maybe 2m meteor scatter operators will finally change over to the latest version of MSK144.

So far I have already had a QSO with 2E0RUS on 2 metres FT8 (IO91 distance 505km). The QSB did get in the way a bit but that is number one in the log at -01/-08. 40m seems to be crowded with the new FT8 mode too.

The actual changeover was fairly stressed here because it came immediately after switching the two IC-7300s over (don't ask why) and following the departure of my Kenwood TS590. Yes, I have done it again - sold my TS590. I did that before, missed it, bought another one and you couldn't rule out me doing that again either. The TS590 is very nice radio, but time marches on here and I just take notions.

Anyway, with multiple instances on one computer, and multiple configurations on each instance, it has not been a simple transition. However, it is done now.

Incidentally, it is true. That was me on Top Band recently. 160 metres. Whatever next?



EDIT Just another thought - the new FT8 mode allowed this genuine callsign - HG90MRASZ

Thursday, 29 November 2018

Spennymoor Rally and progress since the 1970s

On Sunday last I visited the Bishop Auckland Amateur Radio Club rally at Spennymoor, County Durham. This turned out to be quite a big event in a pleasant hall in the Spennymoor Leisure Centre, easy to find and well attended.
General view at Bishop Auckland Amateur Radio Club Rally 2018.
Sometimes I think about rallies and decide "I do not need to buy or sell anything, so I will not go", which seems to ignore the obvious fact that the benefit of rallies is who you meet rather than what you buy. Anyway, the traders soon show you that there was something you did need, it was just something you never realised existed.

I did manage to buy a couple of things and there may be more on those in a later post, so it cannot be said that I bought nothing. The real benefit was meeting lots of people I usually only contact via the radio.

Despite being a person who prefers to keep a low profile, I was wearing a badge which shows my name and callsign. I am of course instantly recognisable anyway, being probably the only middle aged overweight man there with grey hair (almost none on top), glasses and wearing an anorak showing too much tummy ... can't be many amateurs who look like that.

Well, no, better show the badge.

I had long conversations with Graham, G8DST, Gordon, G8PNN, Brian, G8KPD, Derek, G1ZJQ, Clive, G4FVP, and Eddie, G0EHV. I also managed to say hello to Chris, G4FZN. The conversation with Graham, G8DST, was wide ranging. We did agree about developments in Software Defined Radios, many of which are excellent - though some manufacturers seem to overprice what they have on offer. This was a great discussion. We had never met before and we hardly share a band or mode in common. I might be right when I say that amateurs share a common bond even if the areas they specialise in are different. Graham said he reads this blog, so his judgement is clearly first class.

A long blether also resulted from meeting Gordon G8PNN. Once again Gordon managed to get me thinking about 1296MHz. It should be recalled that I had hardly ever strayed above 146MHz before this year, so that would be new turn of events for me. I have to admit now that for a few months I have been secretly reading the Microwaves section of the RSGB's magazine Rad Com and it all seems rather interesting ... but no, not right now. So it was timely to meet Gordon. Great also to meet Derek, G1ZJQ who I usually encounter when he is on hill tops. Brian, G8KPD, Chris, G4FZN and Eddie G0EHV are regulars during activity contests which I do appear on from time to time. Clive, G4FVP, is someone I have worked on the shortest Es contact I have ever made (151km).  So, all in all, I had a great time and learned a lot.

Moving on, there is still something nagging in my mind about the earlier comments on VHF in the 1970s. Several of you commented or sent emails about this period, when over a couple of years local VHF traffic moved from geriatric equipment and wasteful methods to miniaturised modernity. 2m DX moved from the preserve of a few CW and SSB enthusiasts into the mainstream. Those of us who lived through it look back with fondness to the dying days of a 144MHz band which sounded like HF must have done 40 years earlier (with some of the same equipment still in use).

The thing which is nagging in my head was first brought up in an email to me by Bruce, GM4BDJ. Bruce  said that at the time many locals built the G8ARV design for an FM transmitter. This reminded me that the NBFM Handbook I mentioned also made a big point about how easy it was to build a 2m FM receiver and transmitter. The focus was not only on buying ready made equipment, though home built may have been physically bigger and perhaps less powerful in terms of output power. Bruce is correct - home building was the route many followed then.

This thought has been churning about in my mind. Well actually I have taken Bruce's point and run away with it in some strange direction, so the mad stuff in this posting is all my own fault.

Why so little home building now? Then of course it was relatively easy to get frequency stability with a crystal (which somebody else always made). One crystal would be all you needed, before repeaters arrived on the scene. Now it would be quite a task to build a frequency synthesiser and make it passable in terms of unwanted phase noise. Now FM stations routinely use 50Watts output power, something which would have been the preserve of very few back in the 1970s. But then, by a strange turn, we can now find some of the things we need on single chips, if we can accept that soldering resistors is something we can put behind us.

The early pioneers in amateur radio, back before the Great War, would have not only built their own radios, they would often have built their own components. They might have wound their own coils and built detectors. Very soon basic components such as resistors and transformers would have been available for their needs, and specialist radio items too. Later there emerged a tradition of building radios out of standardised commercial components, though I am not sure what the even older "old-timers" said as they could recall building Leiden Jars from scratch. Maybe "these modern folks have it easy in the 1930s with their factory made capacitors. But can they open capacitors up and fix them?".

At about the time of the 2m revolution, Yaesu brought out the FT101. This featured plug-in circuit boards. In the event of a fault you could pull the faulty board out and send it back to the supplier to be repaired (or so the advertisements said). You could buy an extender board to allow you to fix the fault yourself, with easy access. This raised the obvious question, why not just change the faulty board for a new one? And so, at a stroke, we moved from making repairs by using standard components to just changing boards. Behind the sceptical views of the 1970s old timers was the (correct) opinion that minituarised equipment was going to be hard to fix. You would end up having to change the entire board (and never mind the problems with the wafer plugs and sockets on the boards).

And so we stagger to today. The next step in the progression from making components, to changing components, to changing boards, is the inevitable .. just change the radio. I met a technician who was responsible for the radio equipment on a huge cruise ship. Unlike the radio officer of old he had no responsibilities for operating, he just repaired the radios by ... changing the entire radio. Rather than a box of components he has a store of complete radios to plug in. And why not? The radios are now small and cheap compared with years ago, and we all want cheap cruises (?).

Apparently the next step is for the ship to go for a refit and get the entire suit of electronic equipment changed at one go. Why wait for failures? I can see the logic, rather like the fluorescent lighting in a former workplace of mine, where every tube was changed when one got faulty. Once you get the ladder out you might as well do them all.

So I suspect that the next thing I hear about an amateur is that as the green meter bulb has gone out in their LinearAmp Gemini 4, they are getting a new shack. New bench, new PSUs, new radios, and new shiny leather chair. Just go to the shack shop, where you just say what bands you want to work and give them your credit card number, and they will deliver the entire thing. Oh, you do need the skill to plug the mains plug in (and turn the switch on) - a special Plugging In Training Course will be available at extra cost, though switching on is at owner's risk.

Actually, the meter bulb in my LinearAmp Gemini 4 amplifier has stopped working, and I have just ignored it. Amateurs are (or should they be?) made of sterner stuff. We cannot, however, ignore progress. We need to be part of progress. I could not build the superb geared VFO drive on my FT101 when I bought it, but that did not stop me using it and it never did fail. Just because some of us cannot built every bit of our gear from 6BA screws, Meccano, and rubber bands does not make us less able to comprehend our hobby. I think we need to be somewhere in between builders and buyers.

Sure, we lost something when we ditched the Pye Cambridges, the Philips 1000s and the AR88s. At the same time I am not going to set about building an IC-7300 on Veroboard out of components. Progress will inevitably raise the size and complexity of the unit by which we repair things - up from components to boards and even to entire radios in some cases. That does not mean that we do not want to understand how it all works, and even tinker a bit.

I know that Bruce has recently built several HF transceivers with success. I am a bit envious of him there. It is possible to buy kits and you can also find hours of innocent fun piecing together a station. I know some people build their own SDR transceivers (though I have not yet met anybody who wrote all the software from scratch as well). It can be done and it is very satisfying. Nevertheless, I think we should recognise that some of us have learned more about radio because we don't need to build everything from scratch. If I had to build something to run MSK144 on 432MHz out of components I doubt if I would ever get beyond the first stage. On the other hand, if I could only be still enough to appreciate 80m CW I just might have more money in my bank account and I might feel a bit more satisfied with the hobby. Sadly, I don't feel like doing that, but I can share the joy of those who do.

Thanks Bruce for reminding me that the constructional approach was to the fore in 1970, and in many ways it still is. Construction should be at the heart of our hobby.

I think that progress will continue to raise the complexity of the unit which we can replace, in effect by reducing an entire stage which once occupied a large printed circuit board to a single chip. In fact, the whole radio might go on a single chip, at a price we once paid for a component. At the same time, what a magnificent thing it is that we can still build meaningful parts of our stations.

Despite all this we should recognise that we have a special right conferred by our licences to build our own equipment, alter commercial equipment, or assemble our own stations. I hope we never lose sight of that.




Tuesday, 20 November 2018

A pleasant tropo opening

At this time of year I am usually active during the Leonids meteor shower. This year I only have one 4m contact with SP9HWY to show for my efforts. Well, I also worked Henning, OZ1JXY, on 4m during the run-up to the peak.

I seem to have blown up or fried up my 6m linear. At first it looked as if one of the power devices had gone off, but then when I took it all out I discovered that the connections at the power supply had overheated. Whether the power supply issue is what is wrong - initially it did not feel like it was - will need to be checked. The linear draws about 40 amps and the cable was carefully specified to be able to cope, but it has burned the ring connector it was soldered too. The screw connectors on the PSU have plastic covers which have both melted, as has the insulation on the ring connector. The wire, which is doubled and inserted into the connector, has lost its solder and overheated. The cable fell out as soon as I moved the PSU (so much for crimping and soldering), so it that the root of my problem? Nasty. How could I allow such a thing to happen?

So I did not get on 50MHz, though barefoot would probably have been enough. On 144MHz I have been distracted by changing over the transverter IF radio from my TS-590 to the IC-7300. Of course as soon as I did that I spotted a pair of ON stations having a chat on 2m, something which the waterfall display on the 7300 made very easy. Ahhh.

The past week has provided some tropo contacts. A large high pressure arrived across the North Sea from the general direction of Poland. This looked like it might stick around into next week but sadly it has turned right and headed up towards Iceland. Never mind, it did enough to please me.

I often use the GB3NG FM repeater near Peterhead as a propagation indicator, and when a station came onto it calling CQ from the Faeroe Islands I guessed that there might be a lift on.
2m contacts at GM4FVM 14 to 20 November 2018
This is one of those happy situations where I have to leave the callsign labels off the map because they would all run together. The 100km circles show the dx. I think that I can still see a shadow of the hills to the South East of me, but it is nothing like as wide as I used to believe.

The total for contacts was:-

Germany 27
Denmark 8
Belgium 8
Sweden 7
France 7
Netherlands 5
Scotland 4
England 3
Norway 1
Northern Ireland 1
Total 72.

Standouts for me were F6CIS (IN94 1270km) and a series of new squares in Sweden. F6CIS is south of Bordeaux, which is quite a haul for me on 144MHz. At one point the 2m band opened into Germany and I just worked one station after another.

I even worked Henning OZ1JXY on 2m, making it 93 contacts on 4m (almost all meteor scatter) and now 2 on 2m.

In these conditions I was keen to try 70cms ...
70cms QSOs at GM4FVM 14 to 20 November 2018
With my inexperience on 70cms it was clear that many contacts would be new squares and Germany was a nice one to get in the country bag too. Rather more surprising was ON4POO - for a moment I thought I was on 2m. I have worked ON4POO 33 times in the past 9 months (remember when I said I could not get out in that direction?), but this was number 1 for 70cms and a new country on that band.

DL7APV was nice one, having failed to work him on moonbounce a few weeks ago I then did the job on tropo. At 1026km that is new terrestrial record for 70cms for me, and I then worked him the next day on 2m as well. I have now reached 10 countries plus 25 squares on 70cms. Not bad from a standing start a few months ago.

Despite many attempts and several people looking out for me I did not manage to work Netherlands on 70cms, so there is a target for me in the near future. I think it should be possible but the narrowness of the beams in use and the lack of activity have got in the way so far.

There was also a station on 70cms FT8 from the Faeroe Islands but I heard nothing from him at all. That might prove a tricky one to get.

As I often say, I am a generalist. I have flipped from EME to tropo (so did several of the people I worked). I like the chance element in it all - and especially on VHF where the stations appear out of the noise, often a great strength. It is the variety that keeps me interested.

Most of this was on FT8, but I also found time for chats with GM8OEG (on 70MHz), ON6SX and ON8KW (on 144MHz) and GM6CMQ (on 432MHz). Much as I enjoy the efficiency of FT8, SSB is still a grand way to network and reach good DX.

I think that is the tropo opening over for now. The high pressure is not expected to return (but it might). Now I have to find out what went wrong with the 6m linear.



P.S. I have this, so why not show it? 2m with the callsign labels..

Wednesday, 14 November 2018

VHF, 1970s style - A Second Slice

I am not trying to gloat, but ....
QSL for the contact between NC1I  and GM4FVM by 432MHz EME on 27 October.

This takes me right back to the day I received my first QSL back when I was a short wave listener. I am not an active collector of QSLs, but they do have a certain fascination for me.
Thanks to Frank for the direct QSL - mine was already in the post.

Right enough of that.

I have had quite a few comments about my posting on 1970s VHF.

It is interesting that Jan, OZ9QV seems to have had a similar experience to mine. Clearly this is a widely found phenomenon. Jan fell on his feet by getting an IC-202 (in fact the full set of 202s). I never had an IC-202 but they seemed to be the portable rig to have. In the early days everyone really needed to hold their nerve and not buy a Liner 2. We all knew they were terrible but nobody then knew what was coming next - the IC-202 was much better. We still do not know what is coming next.

Tim 4X1ST had an IC2E as well as an IC-202. The IC2E represented the next step for 2m FM radios in that they then progressed away from crystal control entirely and we suddenly had thumbwheel frequency setting. What an excitement that was. I had an IC-240 mobile rig which used a pre-set diode matrix to produce an old-style crystal-type selection knob. The idea of the IC-240 was to look like the IC-22A crystal radio which went before it, but to save on the crystals. What had changed under the skins was that Phase Lock Loop technology had freed us from crystals.

Prior to the PLL we struggled to afford crystals. Although the radio magazines carried advertisements from companies who would etch a crystal for your desired frequency, this service did not come cheap. I recall that in 1977 I bought something called a Ken KP202 hand portable. This was in an attempt to get better performance than my previous Trio brick portable. The drawback was that the Trio had been second hand and came with crystals, whereas the Ken was new and I had to buy them. I struggled to pay for them. This added to the fact that the Ni-CAD batteries were dire and unable to keep the Ken anywhere near its stated 5W output meant that this thing had a short life. If only I had known what was coming next ...

Thanks to David, GM4JJJ, we have a time line of equipment which clearly shows how things changed. He went on to an FT-290 which was rather like an IC-202 on acid. The FT-290 moved on from the VXO to a sythesiser which mimicked a VFO, though with distinct steps.

We are getting ahead of the 1970s here, though it is interesting to note how things developed. Once we had the Liner 2 the mould was broken and progress quickly produced better equipment, first with a wide VXO (the IC-202) and then something which came close to a VFO (the FT-290). For FM gear the compact crystal radios quickly gave way to first wide step PLL synthesisers and to a period where mobile radios resembled crystal control but under the covers had dispensed with the rock-bound concept entirely. LED displays were expensive and not very practical in cars (I recall that Trio had a nice one). The present situation whereby you could programme your FM radio with the necessary channels and scan between them was still a way off.
A comb bound book from the 1970s - is it time more books were hand-bound with plastic strips?

Getting from what went before to what we had by the end of the decade was a tricky business. In my NBFM Manual, published in 1974, (price 90 pence, I recall going to Doughty Street to buy it) by G3TDR and G6JP, a lot of time was spent explaining to operators that (Narrow Band) FM was not as bad as they might think. Obviously there is the drawback of capture effect, which I seem to remember was the often quoted reason why AM old-timers hated it. The authors had a lot of reasons to say that the benefits of FM outweighed the drawbacks. There was the "relative freedom from interference to television, radio and audio equipment", and of course "excellent rejection of impulse noise". They went out of their way to stress the efficiency advantages of having an output stage running at full power all the time rather than just during speech peaks. This was a definite attempt to sell the benefits of FM to the amateur community.

They drone on about how most amateurs of the time know FM only by receiving stations using slope detection. They rightly say this is inefficient. Pretty well all of those stations using HF receivers and down converters were set up to receive AM, and they tuned to one side for FM. Slope detection worked, but badly. All those AR88s, R1155s and B40s in use by the stations I worked were hampering the operators. Slope detection was a bodge. The authors of the book say that "nbfm can yield results equal to am over a given signal path provided a proper limiter/discriminator is used in the receiver to obtain optimum performance with nbfm".

Looking back, I see the classic situation. It was rather like getting away from spark, changing from AM to SSB on HF, and even a bit like today with the emergence of advanced data modes. People resisted. They preferred the established order of things, even though it was limiting them. Back in 1970 this was not a simple change - it was from valve to transistor, from surplus to amateur gear, from old to new, and from home-made to imported. The picture of an amateur in his lonely shack lit by the dim lamps of an AR88 with its unique smell (I used one!) was a romantic one, whereas a tiny Japanese box with two pots and one knob on the front hardly seemed proper.

"Why change?" they asked me, and I struggled to answer, though I knew that it was more efficient and, quite simply, they could work greater distances. This is still my answer to those who doubt the point of data modes. I wonder do they too cling to some idea of the amateur as a romantic figure saving lives at sea or ready to clip on their leather helmet and go into military service, morse key at the ready.

For me it all boils down the question of "what amateur radio is for?" That is still the question that nobody asks today. If this is supposed to be a technical hobby to allow us all to learn, then we need to confront the sort of technical problems that face today's radio world. I doubt if many people training professionally in the science of radio spend much time on ex-Admiralty B40s, splendid as those radios were. In the 1970s they needed to know about FM, repeaters and minaturisation. These days no doubt it is about data communication. Everybody needs to know about propagation. Unless you push yourself you never learn much. So I think that the hobby MUST keep up with technological trends or there will be no learning, and then no hobby.

Those old guys in the 1970s didn't know much about propagation and they didn't want to know. If they could work to the other end of town that was enough. That is not self training of the licensee, that is just talking on the radio. Now we have network radio for that. I still hear those old views today from some those who I speak to, but then again most other do realise the need to modernise.

Even the NBFM manual has something to say about SSB. "it is often said that amateur radio is progressive and this is broadly true - the relatively rapid change over to the single sideband mode on the hf bands shows this to be so. This being the case it seems strange that the amateurs have been so slow to change on the vhf and uhf bands but it is true that a fair amount of ssb is beginning to appear after many lonely years for the early operators". That was 1974, and within about 5 years the change away from AM was complete.

With the arrival of FM, miniaturisation was down to the changover in architecture rather than a sudden move towards smaller components. FM radios did not need high level modulators like those needed for AM. The PAs could be tailored to the constant output power and heat sinks sized accordingly. Gradually better devices appeared and in due course integrated circuits became common. However, to start with, much miniaturisation could be achieved simply by having well designed amateur equipment rather than ancient commercial cast-offs. The mobile radio industry (PYE etc) was already producing smaller more efficient radios but he amateur community only used their 20 year old products.

And so we move on to today. Perhaps we need a modern alternative to my 1970s MBFM Manual. This would try to encourage modernisation amongst radio amateurs now, just as it did then. Of course the technology is entirely different, but the point is the same. We need a shake up every so often. It is great to look back at the "good old days", but that is what they are, old days.

Having said all that about efficiency, the 1970s switch to modernity was largely product driven. A plentiful supply of compact, efficient, affordable rigs built on new technology, be that the FM or the SSB variety, and that took away the logic of sticking with the old museum pieces. Will the Icom IC-9700 do the same for software defined radio as the IC2F and its ilk did for FM? I certainly hope so.
Pre-release photo of IC-9700 (Icom UK).
I have complained before here about the dearth of radios for serious 2m and 70cms work. There seem to be plenty for FM and digital voice. Until recently for SSB and data modes there was the outdated Kenwood TS-2000 and the £3000 Icom IC-9100. Excluding mobile rigs that only leaves the Yaesu  FT-991 which has issues. Now we are getting more details about the Icom IC-9700. From what we know so far this is a software defined radio which looks much like the IC-7300, but covering 2m and 70cms. It also includes 23cms using a built in transverter-type arrangement. So far we believe that it runs 100 watts on 2m, 75W on 70cms and 10W on 23cms.

I was expecting to complain that this radio was out of the financial league of most radio amateurs. I was wrong - again. Now we hear that it is predicted to cost £1795.95 in the UK, this being provisional (no doubt depending on what BREXIT throws at us in the meantime). At that price it is certainly not cheap but it is a lot less expensive than I would have expected. Rather like the IC-7300, the launch of the 9700 may be Icom once again bringing the benefits of SDR to us at the right price. Other manufacturers seem to view the easier to make SDR technology as a reason to raise the price.

Is the IC-9700 likely to be as revolutionary for 2m and 70cms now as the Liner 2 was on 2m back in the 1970s? We do not yet know. It could be that it is the next generation of SDR equipment which will make the difference, just as the Liner 2 was followed by the far more effective products which arrived over the next 5 years.

We shall see. Icom say they expect the IC-9700 to be on sale in February 2019.




Thursday, 8 November 2018

Moonbounce and a bit of tropo

First of all, there was a nice little 144MHz tropo opening here on 5 November. There was also a bit of aurora about but I heard none of it.
144MHz contacts at GM4FVM on 5 November 2018
Not bad at all. It took all day but I worked 12 squares, with DXCCs including GM, G, F, DL and OZ. DK8WK is 1078km so that was not bad either. A new square was GM6VXB who this time was in the wet square IO98. It helps that Martin works off shore and occasionally operates from the strangest parts of the North Sea.

Worth mentioning is that the barometric pressure was not high. What the weather was doing was looking like the pressure was high when it wasn't - it was about 1012 mb (I should be using hectopascals I guess) but pretending to be 1030 with a lovely mild, still, clear day here with no wind and plenty of sunshine. That is one in the eye for the weathermen at the RSGB propagation predictions department. They didn't see that coming (well, neither did I).  

I am not entirely sure how to put all this into context with my contact last week with NC1I on 70cms Earth-Moon-Earth. Jan OZ9QV commented "I am looking forward to hearing more about 70cm EME from you." That is a fair enough comment but I am not sure. I know that many others have caught the EME bug and gone 100% for the Moon. On the other hand I was back on tropo duty the next week.

An email has flooded in from Frank, NC1I, who read this blog and kindly commented. He also sent me a screenshot of my QSO
GM4FVM as seen from NC1I on 432MHz moonbounce.
Click the image to enlarge, as per.

Frank says that I was -24dB on the first day and -26 on the second day. As I was a new station for him Frank confirmed that I was not in his database. Thus I was heard without the benefit of deep search.

It was great to hear from him and also good to see my signal on his waterfall.

He adds "My station uses (48) 15 element K1FO rear-mount yagis. I have mechanical polarity rotation however if I remember correctly at the time of both of our QSO’s I was receiving and transmitting horizontal. Power at the feed is around 1100-1200 watts. I have a cavity preamp that measure around .16 dB nf mounted at the feed. This system has been in use almost continuously since 1994! I live in a rural area and have about 5-acres of property but still there are houses less than 100 meters from my array so I do have noise/interference, especially near the horizon."

The difference is colossal - he has 48 times 15 elements, and I have one 12 element yagi. He has 1100 to 1200 Watts at the feed but I have less than 95 Watts. The key factor of course is his preamp which allows him to hear my weak signal.

I think Super Stations and weekend dabblers are like the poacher and the gamekeeper - we need each other. If we didn't have poachers (that's me by the way, a sort of blow-in who makes the minimum of effort and liberates the salmon) we wouldn't need gamekeepers, but then again, if we didn't have gamekeepers there would not be so much game to attract the poachers. So we live off each other. The little stations benefit from the investment of the big stations, but the big stations get the squares and the nice DX on a regular basis. It seems like a happy balance, except perhaps that there are not enough of either of us, at least on 70cms.

If I wasn't for Frank and his carefully engineered station I could never have done it.

Frank also confirmed what Jan suggested by confirming that even smaller stations are possibilities for improbable DX ... " The smallest station I have ever worked on 432 EME is a 3-element yagi (that’s not a typo it was a three element yagi) and 60-watts so it doesn’t take much. Single yagis with 12+ elements and 50 watts are pretty easy for me to work. My array gain is 31+ dBD."

Whilst my contact with Frank can hardly be described as a great surprise - I did think it was possible if unlikely and gave it a go - it has certainly surprised lots of other people. Several locals have been reeling in amazement. For those who think that moonbounce is something for others comes the dawning realisation that they could do it if they tried.

At the other end of the scale, John, GI7UGV, is one who does try and he got in touch. He was listening the same day as me and he heard DL7APV (I didn't!). John has a better receiver and antenna set-up than I have but he was not in a position to reply. John is known to me as a satellite and amateur television operator but it seems that he has been bitten by the moon bug too. It is a very inviting area to explore. As John said "It actually worked, shouldn't be surprising as was told it would work but actually seeing and hearing the signal ever so faintly in the speaker finally confirms it :)" That captures the excitement of the moment better than I could.

Finally, another amateur asked some very detailed questions about EME and I will post below my reply to him. Each point is open to debate by you all, but I was trying to dispel a few myths.
1) I am just a beginner. That has its merits, because I do not have complex gear or big antennas.

2) There is a "centre of activity" on 144.120 which some people use as a calling channel. Otherwise everybody is spaced out a 1kHz intervals between about 144.105 and 144.145

3) I use a combination of these sites to find out who is on ...
Basically I look to see who is calling CQ and then if they are strong with me I might call them. You can tell the Super Stations as they give their antennas and power on the chat room, 2x12XY/1.5K is two 12 element crossed yagis and 1.5 kilowatts. By comparison mine would be 7H/300 for a seven element horizontal yagi and 300W which is small. However, the gain figures add together and if I can hear someone running, say, 600W, then they should hear me 3dB lower, or 6dB lower if I was running 150W. Most of the time I run 200W on 2m. Generally they can hear down to about -26dB.

4) There is far more activity at the weekends. HB9Q is on 2m most weekends and they use a large dish and can work stations down to 50W and simple antennas. Most stations who take part in UKAC contests could work HB9Q at moonrise or moonset.

5) They don't count countries or squares so much as initial QSOs. After all, once you go via them moon it doesn't matter where in the world the station is in terms of distance. I don't routinely post on the chat room as I don't often call CQ. Sometimes I post a thank you to somebody I have worked which is also a confirmation. If I do that I get besieged by dozens of stations on the chatroom who want skeds.

6) I can get to within 1 degree of accuracy which is far better than I need with my antenna. However, that is once I have got it pointed at the moon. Because my mast is in two  telescoping sections there is play between them and I probably do not get better than +- 2 degrees to begin with. This does not seem to matter.

7) Most people use JT65B. You can use CW and I can hear HB9Q's CW ident perfectly clearly. The WSJT-X software can show all the directional and elevation data if you select "astronomical data". You need to tweak the WSJT-X settings a bit. This is to largely get round the error correction which would otherwise stop you decoding a lot of it.

8) One QSO per day is my practical limit. I have about an hour at moonset or moonrise. QSOs take about 8 minutes and it is all peace and calm compared with meteor scatter.

9) There are so many variables that conditions change over the month. The moon distance changes about 10%, for instance. Then there is Faraday rotation, polarisation differences caused by the curvature of the Earth and the range of the station you are working ... sometimes a week or more would go by when I would hear nothing.

10) Elevation isn't everything. Several of the "big" EME operators in England have no elevation but they do have, say, 2 x 9 ele Tonnas. You soon get to know that your antenna has lobes in the vertical axis which you can use as the moon rises or falls in the sky. With a single antenna and a hundred watts most UKAC stations would be in with a good chance, though a mast-head preamp is the only thing you would want to add if your coax run is over 20m.

Just doing it once is most of the fun. Simply listening and learning is fascinating to me. Nothing about it really makes me think I would want to have a Super Station and high power. I have worked stations on 2m and 70cms, but only heard one station on 6m. So far!

P.S. I find this site handy as once you have told it where you live you can see ahead as to when moonrise and moonset will fall, what the angle will be both horizontal and vertical, and the moon distance...
It is well worth reading GM4JJJ's comments to my last posting.

Many of the generalist "VHF" books are not very helpful. In my view, they tend to make the whole thing look difficult and expensive. There will always be a photo of some enormous Goonhilly type antenna and some QSL cards from an operator who spent a million quid on gear and who lives in a stately home with enough land to put up said antenna (bitter ... who me?). Whatever happened to the concept that this hobby progressed by taking many small steps, each adding a quantum of improvement, and each of us developing skills and knowledge along the way?

As so often, I disagree. I disagree that this needs to be seen as difficult. With folks like Frank, NC1I, around, us ordinary types have a chance of a really memorable EME QSO. I thank him for that.

We need a few gents in this hobby. Luckily there are still a couple of us about.




P.S. Just in case you think I am going cold on EME, I have thought about a separate (small) antenna system with elevation ...

Sunday, 28 October 2018

432MHz Trans-Atlantic EME on 95 watts, OK I was wrong

There seem to be two themes on this blog (apart from "I'm right and everybody else is wrong", but that is what blogs are for). They are

1) our pre-conceived ideas are wrong so we should try this,or

2) my preconceived ideas are wrong and I am a chump myself for not trying sooner.

This posting is rather about the second type.

On 27 October I worked NC1I on 70cms moonbounce. A fluke?
On 28 October I worked NC1I on 70cms moonbounce for a second time.

Here is what I wrote about my plans for 70cms on this blog on 19 July

This is not an Earth-Moon-Earth capable 70cms set-up. Or at least, it isn't designed to be. It is designed to be vastly better than no setup at all. Adequate, not excessive.

Erm. I was wrong about that. Clearly, it is EME capable. Or perhaps "it isn't designed to be" was my wishful thinking/ get-out clause.
432MHz DX Maps on 27 October 2018

OK, lets get this straight. I still think my 70cms set-up should not be EME capable. To review:-

Icom IC-7100, Microset RU432-95 95W linear, 17m of Hyperflex coax, SHF Mini-70 pre-amp, 2m of dodgy RG-213 and a 12 element yagi with a boom length of about 2.5m (part of a dual band antenna).

This is not world class in any way. The IC-7100, admirable as it is, is a mobile rig. I have cut corners - if I had wanted to go for EME I would have bought a 300W linear and a better pre-amp, but the extra cost (£900 !!!) put me off that entirely. I used existing coax which works on 70cm OK but it not earth shattering. I could have reduced the RG-213 to 3/4 or even half its length if I really wanted to - or replaced it entirely. And, lets face it, a 12 element compromise yagi is hardly up to 70cm EME muster.

It is talk like that (the last paragraph) which I criticise others for using as justification for not trying.


Just because it looks difficult is not reason not to try.
As usual, click to enlarge if necessary.

It wasn't a plan, this 70cms EME thing. At least, there was no plan until I heard NC1I. For the past couple of weeks I have been trying aimlessly to get back into 2m EME and failing. Conditions have been poor. Then on 6 October I noticed Bernd, DL7APV, mention on a chat room that he was working on 432. I went to the frequency and heard him so I reported that and he suggested that we try a QSO the next day. It didn't work. Back to square one.

Bernd has what I would call a "Super Station". 128 x 11 elements. That is pretty big, and it is able to elevate, which puts my 12 elements fixed horizontal pretty much into the shade. Why was I not able to work him on 7 October? After a bit of pondering it dawned on me that my antenna is best near to my moonset when the moon is close to my horizon, and at that point Bernd has passed moonset and cannot see the moon (at least for now). If I could elevate my antenna I would be in with a chance. Or I need to try with somebody who is still seeing the moon at the moment when my antenna is working at its best.
DL7APV's 432MHz antenna ...
My immediate reaction to seeing a 33dBD gain antenna is to run away and hide. My antenna has about 12dBD gain. However, I knew I needed to stifle that feeling. The two figures add together, it isn't a competition. Anyway I did not work him, though he said that there was a contest on 27 and 28 October and he would be on for that.

Come 27 October if I had any hope it was of, maybe, working Bernd.  The same problem arose - as I do not have an elevating antenna he was weak and had dropped out by the time ground gain had started to make my signals to the moon stronger.

As it happened my usual EME chat room was off the air. I decided to call CQ. I was using Live CQ to keep an eye on what was happening and I picked what seemed to be a clear frequency. By another chance I was 1kHz away from NC1I who was clear as a bell. This is a bit of a dream of mine on EME - stumbling across someone I can immediately hear. It isn't so unexpected; on looking up NC1I  on it turns out that he has a Super Station and runs 1.5kW, or at least he can run that much.

So I thought it out. If he has 1.5kW and I have 95W, that is going to give him say 13dB advantage over me. I can hear stations down to, say, -26dB so he might hear me if I heard him at -13dB. At the start he was -16dB. At one stage I went out and raised my antenna height as I feared that the moon would disappear behind the roof ridge, but it turned out that raising it took about 6dB off the signal - it was better lower down. Ground gain and height advantages produce funny effects and my antenna height is not that important when it comes to the moon. Of course, I still thought it might be. So the plan was to keep the antenna as low as I could and stick it out until the moon fell low enough towards the horizon for ground gain to give me a chance of working NC1I.

I started calling NC1I at 08:24. He finally heard me at 09:25. I was calling for an hour and during that time I had all sorts of doubts, in addition to the antenna height issue above. Doubts about antenna direction and whether this contact was possible at all or not. I had many doubts about Doppler effect and whether I had factored it in properly. Then, as the moon fell below 4 degrees (and all the other European stations had lost the moon below their horizon) NC1I's signal started to climb up each segment -13, -12, -08, -04 ... so it was easy to see that ground gain was coming to my aid. Also. my antenna was beginning to function better as the moon started to get closer to the horizontal angle at which the boom is fixed.

When I called at 09:24 I knew immediately as soon as NC1I replied that he had heard me. Even though it took a minute longer to receive the signal and decode it, he must have clicked on my callsign. His frequency moved about 150hz, the amount I had miscalculated the Doppler effect. He must have seen me. And then ... well it just went like a normal QSO. Nothing special about my first trans-Atlantic EME contact.

After the contact he was calling CQ and within fifteen minutes he had disappeared entirely. Moonset had arrived.

Just to prove that it was not a fluke I tried again the next day
This time I left it until the moon was lower - under 3 degrees elevation. I was risking moonset behind the hills. The result was the same though.

I know that logic comes in here - if I hear a station at -15dB and he has a 13dB advantage over me on transmit, then he is likely to hear me at -28dB. Add to that the fact that his receive station might have a better pre-amp and receiver than I have (almost a certainty). Thus he WILL hear me. The EME path is usually steady and I bet he lives somewhere which is electrically quiet (like on a ranch!). Still, I never really expected him to reply both times.

As for the distance (5133km on six figure locators) ??? Well, logic also tells me that if I can reach the moon it hardly matters where on the world my contact is. With an indicative path distance of 752,034km on 27th (a mere 747,302km the next day) it matters little which of us is where on the Earth. Still, working round Europe has seemed a lot easier than reaching the US on 2m. On 70cms my lower power is more or less balanced by more antenna gain so my ERP is much the same, so why am I surprised to do it on 70cms first?

I suppose these 70cm figures give a clue to my pessimism built on years of ignorance

2012 NIL
2013 1 QSO dx 92km (GM)
2014 NIL
2015 1 QSO dx 30km (GM)
2016 1 QSO dx 5km (GM)
2017 1 QSO dx 82km (G !!!)
2018 47 QSOs, 8 DXCC, 2 continents, dx 5133km

Lessons to learn? I am often wrong. I can even believe my own negative script. 95W and 12 elements did do it and I suppose if I had done a careful budget I could have worked that out in advance. Still, my job was to make my tiny signal reach him, which involved sticking at it until the ground gain kicked in, not raising the antenna too high, paying close heed to the moon's movements and not allowing my doubts to overwhelm me.

Here I go again. "I am surprised by those two contacts"

I should have tried this ages ago.



Tuesday, 23 October 2018

Galashiels Rally and how you should spend your money on VHF

Last weekend I visited to Galashiels rally. I should have taken a photo but it never occurred to me. Anyway there were plenty of people there and various trade stands. I bought a solder sucker (90p), a switched mains plug (£1.60), two fixings for wire antennas (50p) and a rather flash loud speaker for £6.00. This was all swamped by the fuel to get there and back, which I estimate at £10.00, plus an hour's drive there and another hour back. You see, I compare all costs and all benefits.

"He is mean".

It was worth it though to meet various people, including a couple of hams who I have worked before but not met. I enjoyed a chat with Dick GM4PPT who is a stalwart of VHF operation, and Robin, GM7PKT, who I have contacted quite a few times on FT8 on the 144MHz band. What both these amateurs have in common is that the paths between us are very difficult due to the mountainous terrain. So it was good to have the time to chat.

Robin's experiences with FT8 are very like mine. In fact the mountains which surround him are much taller than the hills I have to deal with. Despite this he is having success with FT8. This, and comments on this blog, all make me ponder about the success we have been having with FT8. I was a regular user of JT65 and JT9 before FT8 and somehow I never seemed to do as well with those modes, The facts though are that FT8 is slightly less sensitive than those modes. I suspect that a lot of it is due to the greater take-up of FT8 on VHF.

Also at the rally were a lot of second hand radios. There were the usual rather ancient VHF rigs, but there was also a rather neat looking Icon IC-7100, the very rig I was claiming is quite good value at £700. There it was at £550. And they didn't sell it during the rally so I asked how to buy it afterwards just in case.

At the same time I met another amateur who had brought a year old 2m and 70cm radio which he was offering for sale at £35 and eventually he took £33 for it. He then tried to buy a 40 year old 2m FDK for £25. Here he was bringing a perfectly good modern radio and trying to upgrade to an ancient one. He admitted to me that the FDK was very large and would probably not fit in his car. I asked him why he would make a swop like that and he said "nostalgia". In the end somebody else bought the FDK from under his nose - no doubt soon to find that it doesn't have CTCSS or 12.5kHz channel spacing and it is pretty deaf anyway.

Thinking a bit more about all this, I have come up with my own theoretical "law of diminishing returns". This is entirely non-scientific and definitely not a law. It is just my theory about how to best spend money. It was prompted by the experiences at Galashiels and also one particular local who has an interesting approach to VHF operation. The guy in question has outdoor HF antennas, and used to be a keen VHF dxer. For VHF now he uses an indoor quarter wave whip on a magnetic mobile base, stuck onto a biscuit tin lid.

I cannot help feeling that running a radio into a quarter wave vertical and using a biscuit tin lid for a "ground plane" is not a really good use of resources. So I have come up with a graph to represent my law of diminishing returns (which, again, isn't a law). The graph shows a better way of gaining returns for your money be showing an alternative red line.

The idea is that if you use an indoor vertical it doesn't matter how much you spend on a better rig it makes little difference. Your money is better spent on ancillaries like masts and antennas, or coax and pre-amps. Well, that is my view.

Of course lots of people have problems putting up large outside antennas (though the biscuit tin lid guy can as he has HF ones), or have planning issues, but it might be worth a try with something simple - more than buying a new radio anyway. Even if you go portable because you cannot get a good antenna up at home the same general rule applies, so long as you can lug the associated gear out to your portable site. It will usually make your station work better than the same investment in a fancy radio.
The GM4FVM VHF cost/benefit graph (aren't results measured in "JIMMYs"?)
 You will probably need to click on this to enlarge it enough to see it.

I am suggesting that after you have got a "new" multimode (by which I mean modern, the second hand IC-7100 at Gala show would do at £550 and save you some dough for antennas), spending more on radios just keeps you nearly flat on the dotted line. You will have diminishing returns in that there still is a return, a better rig is a better rig, but you get less benefit in term of results for the £££ you spend now than on your basic radio. On the other hand, spending on other things (along the red line) brings you steady returns. I have found that spending a £ on the red line brings a considerable result, whereas spending a £ on the dotted line seems to do very little..

Who am I to tell people how to spend their money?

I have no right to suggest all this, but I do believe that you get a lot more return out of improving your station generally rather than improving your radio. Yet at Galashiels nobody was selling yagi antennas, good co-ax or masts (well, there was one old but nice second hand Clarke pump up mast which I looked at for a long time!).

So what is the way I am measuring "results"? Well, based on my experience - locator squares, distance, countries, surprise long distance contacts, learning about propagation, lots of things. I never said my theory was scientific.

Hey, results are measured in units of increased utility (work that one out).

As for my order of things to improve, well that is based on what I see going on around me. A gable end mast is just a pair of T and K brackets attached by expanding masonry bolts into the end wall of a house - fine if you have a masonry end wall, but there are other ways of doing it. If you have a vertical, get it into the clear and as high as you can using a gable end mast. Ideally use something like a half wave which does not need a biscuit tin to ground it. Next thing is a directional antenna, even if it has to be turned by hand. We used to have TV rotators but nobody has made one that passes the CE test so they are not available in Europe at present. Rotators are simple things, just a motor and a gear box and you can usually get them cheap second hand.

Here is s simple example. For a while I used a vertical on 50MHz. I did very well during the sporadic E season. Then I got an HB9CV (the Diamond one) mounted on a simple bracket cadged off a neighbour and supported by 1.5 inch thick-walled alloy tubes. With the vertical I could work Europe; once I had the HB9CV I could work across the Atlantic. It wasn't easy, but it was possible.
Simple, HB9CV, old TV rotator, good enough to work Puerto Rico on 6m.
The step up in results from a vertical to a directional beam, even a simple one, was huge and far greater than any investment in radios or linears could have done. I was very chuffed when I worked across the Atlantic for the first time. That antenna opened the door to meteor scatter and aurora work too. Better antennas are better on receive as well, so they beat linear amplifiers by a mile.

After that, a better antenna - I am not suggesting that your first steps in improving your antenna are likely to be your last. I certainly have tried my first setup and then upgraded in every case (except, so far, 70cms). As you know, none of my current antennas has a boom longer than 3m and that is enough for me. My advice is to pay little attention to the number of elements and more to the length of the boom (the HB9CV being an honourable exception).

It cost a bit, but I found a tilt-over, crank-up, mast to be very valuable - also more valuable than a linear. For VHF use it allowed me to get to twice the height over the ground of the gable end type of fixing. Partly getting a tilt-over is due to me getting older and less about to climb and haul things about up ladders. Also I live in a wild and windy place. Once again a wall-fixed tilt-over mast is enough for me, free standing masts are a step too far here.

Whilst I rank the free-standing mast as being more useful than a small linear, I don't rate big linears anywhere. I do not see the need for full legal output anyway, and I am content with moderate power. After a while barefoot is not enough, but I am happy to look in the magazine at what the contest operators are using and get with about 3dB of majority are using.

Better coax. A lesson we all have to learn one way or the other. It is expensive but it is worth it and in my book worth more than the same amount of money spent on the radio. Coax does not last for ever, and when you need to change it there is a chance to improve it. A mast head pre-amp - the final essential item on my list to a achieve best results, something to bring your receive performance into line with your transmitting ability.

Then, maybe, someday, a better radio. I like better radios, but I am kidding myself if I was to claim that they really get much better results.

I bet I am criticised for saying all this. If it was not for the subsidy the amateur radio magazines receive from equipment sellers advertising really expensive radios then we wouldn't have a radio press. And we all love a nice radio, including me. Yet when I want to buy a £200 mast head pre-amp I had a devil of a job finding somebody to sell me one, whereas I can buy a TS-890 at £3999.95 (carriage extra) - reduced from £4299 - a snip - anywhere.

By all means spend your hard-earned money on a shiny new radio. But please, think about climbing the red line first.

"There he goes again - off on his hobby-horse."

"I bet he buys some fancy radio soon - he is just softening us up."



Sunday, 14 October 2018

My grudging appreciation of the Icom IC-7100

Yes, I know I have promised something more about 1970s VHF, but it is all just too complicated. I am working on it. In the meantime, this ...

I believe that the major Japanese manufacturers are puzzled by the Western habit of buying "mobile" radios and using them as base stations. Why, for instance, when Icom offer us the IC-9100 base station, would anyone want to use the IC-7100 mobile radio from home?

Erm, maybe because the IC-9100 is currently £2799.95 while the IC-7100 is £999.95.

Now of course the IC-9100 is a better radio than the IC-7100. It is better equipped, it has a built in ATU, it will produce 100W on 2m and 75W on 70cms (or at least it claims to, I have no personal experience) compared with the 7100's 50W on 2m and 35W on 70cm. With the 9100 you can add a module for 1296MHz, if you have £623.99 to spare for that.

If you accept that the IC-9100 is better, even though you might wonder if 180% more £££ would bring you exactly 180% more joy, that does not mean that the IC-7100 is easily written off as a base station.
The IC-7100 control box at GM4FVM

I must declare my interest. I have had an IC-7100 here since August 2013. You can look back in this blog and find me moaning about the "clicking" sound on transmit, which I can find but nobody else has ever heard (maybe it is inside my head). You can also find me complaining about the low average output on SSB, which I resolved by using an outboard speech compressor. Apart from that my total list of complaints is NIL.

(EDIT -  here is some of it

Five years is a long time for me to hold on to something which I might have doubts about. That's the thing about the IC-7100, it just does its job. It works. I have never doubted it. OK, along will come the IC-9700 which will I guess make a better VHF  base station than even the IC-9100. But will it cost £999 new?

I noticed a couple of second hand  IC-7100s on eBay. They sell for about £700, or even less. That is quite a bargain. No doubt there are some poor condition ragged ones about, perhaps modified ones too, but mine has had nothing more radical done than to add an N-type socket to the VHF side. Any others like it on sale might be a very handy used radio.

Let's think about it. Rather than comparing it with sets at three times the price, at it's own price, second hand, it is streets ahead of anything else around. The Yaesu FT-857 is an ancient plodder by comparison - it doesn't have IF DSP like the IC-7100.

The 7100 is still in production. You could pay sky high prices (£1000++) for an out of production IC-910, and not get the USB connectivity of the IC-7100. The 7100 just needs to have its USB plugged into the computer with no audio data interface. Sure the IC-910 is better in many ways but the 7100 gives you HF for free.

There are lots of out-of-production VHF radios you could buy second hand for maybe half the cost of the IC-7100. The problem with this is that they are now so old that their performance is below what we have come to expect. Solder joints are failing and capacitors are drying out. The IC-7100 is stable enough for data in that it does not drift significantly. It is probably more sensitive than the old rigs but maybe not quite in the latest transverter league. For £700 you would get solid performance by comparison with older equipment, but it is not quite earth shattering.

The IC-7100 was designed with FM and DStar operation in mind. It has good cooling and an effective fan. This means that it is very happy with high duty cycle work, and data seems to pose it few problems.

There are some nice aspects of using the IC-7100. It has separate PTT outputs for HF and 2m/70cm. This means you can use a linear on 2m and a different one on, say 4m or 6m, and the linears would only come into use when you select the right band. Of course, HF, 4m and 6m are all one one PTT output, and 2m and 70cms are on the other, just like the RF output sockets. I certainly made us of this feature. Also, as the control head is separate I could mount the radio at the point where the 70cms coax enters the shack whilst having the control box on the desk. This saves some lossy coax.

For the European market the IC-7100 comes equipped with 70MHz. This was a bonus for me at the start as I already had a 4m transverter. I planned to stick with the transverter. Within weeks I was using the IC-7100 on 4m exclusively. Later I used the LDG IT-100 automatic ATU with it on HF and that proved very satisfactory. After that it was my 6m rig, then my 2m rig, and now it is my 70cms rig. In that role I can produce a map of what it has done because it is my only 70cms transmitter (apart from FM which I only listen to).
70cms contacts at GM4FVM 30 June to 14 October 2018 (F1BHL/P sadly missed off the bottom of the map)
If this looks modest, it is 70cms and I had my first QSO on 30 June which is three and a half months ago. All of them on the IC-7100 - though lately with a 95w linear. On all bands I have had hundreds of contacts on the IC-7100, from Greece on 70MHz to Canada on 50MHz, to Australia on 28MHz and lots elsewhere too.

There have to be some downsides. My early model came with a fairly poor microphone. The physical design with its sloping display is a bit odd. Spinning the VFO feels rather peculiar as the control head tends to move - it needs the free moving finger cup which the IC7300 has. Some of the logic for switching between meters on the touch screen display seem strange. Some people don't like the monochrome display but it never bothered me.

This is a very personal thing. I borrowed an Icom IC-910 and hated it - the ergonomics appalled me. I do not like the looks of the TS-2000 (but it is discontinued now anyway). The IC-7100 is not a radio I love either. I cannot deny it has served me well. As a new buy at the current price of £999 (and less on the grey market) or about £700 used, it really does compare well with older models in the same market sector (which means the Yaesu FT-857). As for anything older still, I wouldn't consider any of them if I could find a clean used IC-7100. It certainly is not perfect, but it is modern and it works.

In case you think I might throw my IC-7100 out when I do eventually buy a VHF base radio, have no fear. I have plans for using it mobile - goodness, a mobile radio used mobile! Of course, I cannot buy a VHF base station until somebody makes one I would want or could afford, but that is another story.