Tuesday, 22 September 2020

Using the IC-9700 as a dual band FT8 decoder plus heaps more tropo.

 OK, TROPO - loads and loads. New squares, new countries, but more of that later.

Stations worked at GM4FVM 15 to 21 September 2020. Red pins for 2m, purple for 70cm, light blue for 23cms. It is only a week's activity you know.

That might be an image that needs to be clicked for a larger version ... not to mention the others.

Yes, it is true, I monitor several bands at once. As someone asked how I do it I hope to cover this in a later posting. I cannot listen on several bands at once because few humans can do that. However, I can have various displays on my computer screens, and I can monitor multiple bands that way. This allows me to jump up and down the spectrum and sometimes "do the treble" by working into a country on three bands in quick succession.

The object of this posting is to explain how I am using the IC-9700's dual band capability to monitor data modes (and not just FT8) on two bands at once using the IC-9700. There is nothing very startling about this - you can listen to SSB or CW on the loudspeaker on both bands. On data most people will connect the IC-9700 to a computer using the USB socket. That is fine for one band. I use the other audio output from the back of the 9700 and feed that into the computer to cover the second band.

For this purpose I picked 144MHz and 1296MHz, because I use an IC-7100 for 70cms. You can use any two of the three bands on the IC-9700. I also decided to use MSHV to decode the second audio stream, simply because it looks different and I am less likely to get confused. Getting confused is not unlikely - the IC-9700 has a complex system of VFO A/B and band and sub-band which can be very hard to fathom.

So I went for simplicity (?!). As the sub-band cannot be used for transmit, I reserved the second audio stream for decoding (listening) only. The second display is just for reading, it does not report reception to PSK Reporter. This is because I will be switching between bands and the second stream does not have CAT information. If I enabled reporting on the sub-band it would keep reporting the wrong band if I switched between bands. 

And anyway, I need to be able to get my head round it. Everything recorded on the sub-band, whatever frequency, turns up on the secondary MSHV screen. I work on the current WSJT-X screen - always. I switch between bands by pressing the upper multi-function button ("M/S") which swaps the main and sub band frequencies. The WSJT-X software I use for the main working area keeps up with the working frequency, but the secondary one doesn't. I know I can only "listen" (watch?) on the other sub-band one. When the working band is 23cms (on my left), the monitored one is always 2m (on my right), and pressing M/S swaps them over. Simples.

Main-band reception of 23cms GB3NGI beacon on JT4G at GM4FVM

Simultaneous sub-band reception of 2m GB3NGI beacon on JT65B at GM4FVM

To show me receiving both of these at once I had to use a beacon. I would rather have done it with FT8 and active amateurs but I forgot during the recent tropo lift and now everybody has gone off the air. But obviously both bands can be heard and therefore decoded simultaneously. If you wanted to transmit in the secondary frequency you just press the M/S button to bring the required band into use.

It really could hardly be simpler. To add the second decoding software you can add another "app". In my case download the latest version of MSHV, install and run it in a new folder, and connect the audio to it. For that you need  ... an audio cable with a 3.5mm plug on each end.

EDIT - I did not know it at the time because the IC-9700 manual doesn't mention it, but I could have used a second channel on the USB audio output instead of a analogue line. Thanks to Greggor for pointing this out. See here for an explanation. The analogue system described below will work, but the two steams via USB will have less noise and save some wiring. 

If your computer has a spare audio input socket, just plug the cable between the sub-band socket on the IC-9700 and the computer. In my case I did a lash-up first with a USB audio card from eBay (cost £3). That worked, though the signal/noise on the sub-band was quite poor. I added an audio attenuator (also a small sum from eBay) as that device only had a microphone-level input. It wasn't great but it proved everything worked.

Next step for me was to add a better outboard sound card - one I bought a few years ago in the days before USB audio input direct from commercial rigs. This is better quality and it has a line-level input, but it still cost less than £10. The S/N on the screen was better, the reports higher and I have stuck with that.

Cheap USB audio card with attenuator

As I say, there is nothing special about this. We used to connect our audio output from our radios to our computers in the early days of PC based data modes. Just as in those days, once you plug the lead into the IC-9700 sub-band output you will not be able to listen to the radio on that speaker (but you can turn on "listen" to the audio stream in the computer). You have to set the sub-band volume control for the correct reading on the software, in my case made easier thanks to the attenuator. But strictly you do not need to attenuator if you can balance the volume controls on the radio and in the computer (and MSHV gives you a volume control too).

And it works! I often leave the rigs running while I am out of the shack. Normally that means monitoring 2m, but now of course both 2m and 23cms on the IC-9700. I was passing the shack with my coat on about to leave when I spotted something on the MSHV screen. It turned out to be DF5VAE on 23cms - I just pressed a button and I was ready to try to work Charly. It took a few moments. His linear amplifier had failed but he was stronger barefoot. We quickly completed a contact for my longest DX on 23cms, with a new square and DXCC into the bargain. Without a second monitor I would never have been able to do it.

The same thing happened several times during the past week, and in both directions. I was on 23cms when I saw something interesting on 2m too. Why not? The IC-9700 has two receivers, so why not use them to monitor two bands at once?

Of course anyone else doing this will probably not follow my idea of using two different bits of software to decode each stream. I do this to make it clear to me what is happening - MSHV for sub-band (right hand of screen), WSJT-X for main-band (left hand of screen). I like to know where I am. 

If you are adding multiple instances of WSJT-X you need to follow the guidance on the WSJT-X website (link on the side bar of this blog). Basically you need to give each rig a separate name (I have four instances!). Maybe I will cover this in the later posting. Anyway, it is very easy just to use MSHV for this purpose. Easy, Jim, your mother never liked you doing easy. But it is, and it works for most things (but not JT4 from GB3NGI beacon as MSHV doesn't have that mode).

 Right, time for some tropo reports.

On 13 September I worked DJ8MS on 2m. That is not so unusual, but what happened after that was unusual. For the week 15 September to 21 September there was tropo every day. A large high pressure system moved in over the North Sea, and although that faded after a few days, another high from the Atlantic merged with it. Hepburn predicted it very accurately of course.

By 17 September the PSK Reporter page for 70cms was beginning to look more like the normal one for 2m.

432MHz as shown on PSK Reporter on 17 September 2020

At different times propagation moved around covering France, Belgium, Netherlands, Denmark, Norway, Sweden, Northern Germany, Czechia (!), Poland (!!) and Estonia (!!!). And while 2m was like a bear pit, 70cm was busy and even 23cms was a bit busy. 70MHz, a band which can produce some good tropo openings, was also affected. Just goes to prove it is worth monitoring as much as I can. 

Busy is not the only way to judge it, so how did I do for DX? Well, as is so often the case, things got better just before the opening ended. And then, just when you think this is going to get even better, it is over.

In 7 days I was actually operating for 21 hours and 33 minutes to work 65 squares in 15 countries. Best DX was, perhaps appropriately the last of 170 QSOs, to ES8TJM in KO18 at 1575km. Wow.

The highlights were ... everything ... , but to look at each band in turn (except 4m which had 5 tropo QSOs and 6m one on Es):-

144MHz contacts at GM4FVM 15 to 21 September 2020

Hard to know what to say about that.

97 QSOs to 49 squares in 12 countries.

I look back at the log and, quite frankly, I cannot recall some of the entries. I am reeling. I need to look more carefully at it to appreciate the individual detail as well as the whole thing.

Thanks to ES8TJM for my first 2m tropo contact to Estonia. Thanks also to HF0BW who would have got the award for best DX to Poland had ES8TJM not won it by 19km. And thanks to the rest who were making it a very memorable week.

432MHz contacts at GM4FVM 15 to 21 September 2020

56 QSOs to 31 squares in 12 countries. Loads of new squares. Thanks to SM1FMT for my best ever tropo DX on 70cm for 1359km to JO96 in Sweden. Surprised would be the word about that one. 65watts and 2.5m boom yagi. Eh? And as I keep saying, two years ago I didn't even have a 70cm antenna because I thought I would not work anyone. And thanks to OK1VVT for my first contact on 70cm with Czechia.

Let us get this straight. Unlike some (those who regard themselves as part of the Senior Service of amateur radio) I do not sit on the sidelines and wait to pounce on the choice DX like some radio-spider. I know that other operators need GM as a country, or IO85 as a square, and I like to do my bit. 

There are some choice bits in there which I would have missed had I not got involved with the masses. F6DBI is a nice bit of DX for me on 70cms. I have worked him a few times on 2m, but this was only the second on 70cms. I have not heard so much of ON4POO lately but a first contact on 70cms was a pleasure. I still reckon 70cms is very interesting. Working GM0HBK is a treat, and working DF5VAE or DL7APV is a joy. And that bag full of OZs are always interesting.

If they want to contact me, I will try to work them. How do I know - I might be the best bit of DX they have worked all year. And, frankly, these contacts are all equal value to me whatever record they may break, or not break, as the case may be. I only go on about the records because they keep surprising me.

23cms was great fun. Now I can monitor it without taking my eye off 2m.

1296MHz contacts at GM4FVM 15 to 21 September 2020

12 QSOs to 10 squares in 6 DXCC. But what QSOs! Thanks to GI6ATZ, F5APQ and PA0O for my first contacts on 23cm into Northern Ireland, France and Netherlands respectively. And thanks to DF5VAE for my first contact on 23cm to Germany and my best DX on that band at 1001km to JO64.

I had several requests to try to contact stations in Poland on 23cm and Czechia on 70cm on CW amongst other things, but none of it worked. Still, perhaps that saved them listening to my crappy morse, so it was not all bad. Plus I still have some goals in my radio life.

Sorry this article has been so long but how do you describe the last week in any other way? Now that I can monitor three bands at once and hop between them I have been able to range across the frequencies as conditions changed.

Towards the end of the opening, on 21 September, the conditions went into overdrive. There were whistlers moving up and down the band. Stations had signals which were dissolving into dust rather than forming FT8 traces. I sat and watched superstations working Finland and Latvia and just monitored them off the back of my beam. No need for me to get involved because I have neither the station nor the drive to try. Maybe I am what a certain President would call a "loser" for not wanting to plaster myself over the clouds. But how can I not be content with what I did this last week?

If you were there, I hope you had a good time too.

And if you have a log periodic ready for that IC-9700, what is stopping you getting back on?

A radio-spider? What is that? Have you gone totally bonkers Jim?




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