Stuck masts and falling screwdrivers

I thought my greatest problems at the moment were the holes made in the drive by a marauding hedgehog. I even have pictures of him/her (can there be two of them?) wrecking the place thanks to an infra-red trail camera. They are entitled to be here, but can they not use the drive to pass along rather than dig it up?

No, things got worse when my main mast suddenly started to give problems. The main mast is a CUG 12m three part square section mast, with my 6m, 4m, 2m and 70cm antennas on top. I will no doubt give more details on the antennas later, but for now it is the mast itself that took all my attention. The mast is raised and lowered using a lead-acid battery powered winch. I recently replaced the winch and the wiring and then fixed up the original winch as a spare.

First problem was that it started to go up and down slowly. Having replaced the winch I thought that it was unlikely to be the problem. Then it would only go up twice before the battery needed to be recharged while before it would go up and down eight or ten times between charges. Although the battery appeared flat and it would not raise the mast, the smart charger declared that it was 100% charged. Most odd.

Then it blew a 25 amp fuse. I had increased the fuse from 20 amps to 25 amps during the re-wiring because the previous one had got scorched but it had not blown. It seemed unlikely to me that the 25 amp fuse would blow under normal circumstances.

GM4FVM fault finding with his mast and almost new winch (photo Mrs FVM)

Clearly something was adding a heavy load to the winch. I would have to investigate further. 

I then recalled an occasion 10 days before when I had tried to lower the mast on a windy evening. The middle section of the mast had jammed about 30cm before the bottom. This was due to the wind pushing the mast aside in the bottom tube and it then caught on a piece of poor galvanising and stuck. There are a couple of bits of poor galvanising on the mast and this has caused trouble before. Perhaps this was the cause of the current problem.

As in all good scary TV police reality shows (isn't "24 Hours in Police Custody" the best of these??) I had to go and seek CCTV images to find the culprit. Luckily the Anti-Hedgehog Trail Camera (AHTC) recorded the whole event on 4 June 2026 starting at 21:25.34 when the temperature was 11C (flaming June weather in IO85) and the sound track proved it was windy. Ah ha! Evidence. PC Dixon has found the culprit - me. Well, actually a combination of the construction of the mast and the wind - and me.

I had trouble lowering the mast fully that night ten days before. When I tried to lower it the middle section stuck and the cable lowering the upper section (which confusingly is on the middle section) fell slack. Now I was worried at the time that when the slack middle section cable eventually tightened up it would not fall back fully on the pulley, so I reckoned I had better get the thing down properly.

By repeatedly raising the mast a small amount, about 50cm in total, and lowering it again I kept returning to the point at which it was sticking on the way down. I only did small movements to prevent the slack cable from failing to seat back on the pulley. Eventually a slight drop in the wind allowed the middle section to drop past the sticking point and it was fully down. 

What I had not noticed in the dark evening was that the very thing I had been trying to avoid had happened. When the middle section cable had tightened up again it had fallen down the side of the pulley. This meant that the cable on the middle section was turning round directly into the inside of the mast rather than going smoothly over the pulley. This increased the resistance, added strain on the winch and was potentially going to lead to the cable wearing and breaking.

It was hard to see this from the ground, but up close the problem was obvious:-

Cable down side of pulley

The danger of this wearing down strands of the cable to the point where it snapped was sufficient to get me to fix this right away. I happen to know that I started to fix it on 15 June 2026 at 09:32:10 and when the temperature was 15C. This is from intelligence gathered by the hedgehog detection system.

I knew that all I had to do was to generate some slack in the cable and then pull it over the pulley. To do this all that was needed was to push the middle section of mast into the bottom section while holding the top section fixed to the middle. Impossible in my current ancient weedy state as I do not have the strength left to push the mast in while it is lying on its side with rotator and antennas on top. Simple, just fix the upper section steady and tilt the mast vertical when it will fall back together under gravity and the cable will go slack. That is how it went slack in the first place. Well, maybe.

I had got confused because it was the upper section that I needed to fix in place whereas I tried to fix the middle section. I did this by wedging two large heavy screwdrivers into the gap between the sections and turning the mast vertical. So I wedged the middle section rather than the top one, but it worked and at least I had proof of method for getting them in the right place next time.

Two old heavy screwdrivers in the wrong place, but the idea works

While I had the mast vertical I momentarily pressed the "In" button on the winch control rocker switch rather than the "out" one. It only moved a fraction, but that was enough to release both screwdrivers from a height. They clattered down the back of the mast, hitting the mast brackets before scattering. One has never been seen since. I have no idea where it went. What could I do, apart from sending Mrs FVM to look for it and she has not reported back since. It a big thing but it is lost. This just shows that a hard hat is needed for working on antennas as a large screwdriver falling from a height could do a lot of damage to the head.

Luckily it turned out that one screwdriver was enough to hold the top section up and everything worked out fine. The cable is now happily seated on the pulley and everything runs smoothly. 

Next snag is that the mast jammed briefly at the same point last night during windy conditions. This time the cable did not lift, but it could have. I must get round to filing down the uneven galvanisation at the point where it jams.

Things to note:-

Beware slack cables on masts 

Beware falling screwdrivers

Beware large screwdrivers disappearing into thin air

Beware hedgehogs vandalising your drive.

Hedgehog attacking GM4FVM drive around 00:20 local time

In fact, just be careful.

73 Jim

GM4FVM 

 

 

Mostly Sporadic E

Time for a short summary of the past two weeks of operating. This has been Sporadic-E on 6m, 4m and 2m, and flat-band tropo on 70cm and 23cm.

 

Contacts at GM4FVM 31 May to 13 June 2026.

There was an all-time new DXCC in the shape of St Lucia on 6m. This was an all-time first for me on any band.

Contacts at GM4FVM 31 May to 13 June 2026.

Over all, not bad for two weeks  I would say, but Africa and Asia sadly under represented.

Vraiment pas mal. 

73 Jim

GM4FVM.

What is it with 23cm?

What is it with 23cm?

I was reading a fellow GM's blog today and I saw that he said that working UHF was "highly addictive". 

Today I have been working my three-band trick. Six meters open, four meters stuffed with OIRT broadcast stations in Belarus and Ukraine, and me on 2m working OE and 9A. Surely that would be fun enough for anybody?

That is good but it is not enough for me. Clearly I need THAT --- and I need MORE.

When I started out on my ham career microwave bands involved dark arts. Mysterious waveguides, unaffordable coax the size of drain pipes, and wartime Klystron valves. Or the other route involved triplers such as those made by Microwave Modules. Some folk started at 144MHz, tripled to 432 and then tripled again to 1296, resulting in an FM signal as wide as a barn door. And this was a barn door that drifted up the band. To hear this stuff you used a receive converter.

I never got near microwaves then. Even for 144MHz I started off using a valve receive converter down to 28MHz and then into a deaf AR88. My transmitter started with an 8MHz crystal and multiplied up to 144MHz, so going up six more times seemed like a crazy idea. Or too much like hard work.

Then, decades later, after the passage of  much RF, I was left a brand new Icom IC-9700 by David GM4JJJ. When I mentioned to Neil, G4DBN, that I had an IC-9700 but I only used it on 2m, he sent me a Wimo 28 element yagi. So there I was with rig and antenna. I reused some old coax and I was on the air on 23cm on 1 September 2019.

My limited knowledge, formed over 40 years before, was that this was a very difficult band to manage. This stuck with me for a while. Plus I had the idea that this little antenna would surely only send out dibbly-dobblers and I would never be heard anywhere. I reckoned the results would be pitiful. You can judge for yourself how wrong I was.

1296MHz contacts at GM4FVM since 1 September 2019

Click to enlarge images, blah, blah, etc, etc. 

OK, it has taken seven years to do all this but I have had 247 QSOs and worked 14 DXCC during that time. True, 32 of those QSOs have been to JO46 square in Denmark. The fact that my most worked square is in OZ is really due to geography. My antenna is basically pointing straight across the sea at Denmark, whereas towards the rest of Scotland it points at the Lammermuir Hills followed by the Pentland Hills and then the Highlands. Generally working Denmark is reasonably simple if there is a tropo lift across the North Sea, and there often is. This high number of contacts is despite JO46 being at least 630km away and beyond aircraft scatter range.

During a tropo opening 23cm often becomes my favourite place. I can forget all that stuff I believed in all those years ago. My ODX for a tropo lift was to LY2WR, 1719km away in KO02. That was about 1500km further away than the best DX I could imagine on this band before I started.

Now of course my station has altered slightly over time. I found that the IC-9700 drifted on 23cm so I added a Leo Bodnar GPS frequency standard. I upped the power using W6QPL amplifiers, first to 50W and then (thanks to Sid, G8SFA) to 150W. At various stages I have been using a 36 element yagi, and at other times reverted to the original 28 element. Although there is supposed to be a 2dB difference between them it seems to matter little. I am still using 19m of Hyperflex coax which manages to lose half the signals thanks to having 2.9dB loss at 1296MHz. I now have an SHF-Electronik MVV-1296 masthead preamp which has a noise factor of 1.5dB.

My station is modest. I could make it better. To me that is worth thinking about but not the point. I do not run a kilowatt or have superb antennas on any band. I work on five bands and I cannot have a superstation on all of them. Hopefully over time it will get gradually better, but my initial effort to get going has proved that 1296 is indeed worth the effort.

How can I illustrate where I can work to on this band? What about listing my five most recent QSOs (in reverse order of course, this is my blog after all)?

1) 30/5/26 G4ALG/P. IO81. I did not get Steve's exact location but this was over 400km and not an easy path over the Cheviot Hills and then the Pennines. It was his best DX on 23cm to date. Unusually for me this was a CW QSO. It was assisted by aircraft scatter. I like helping someone to their best DX, even if he has to try to understand my awful CW. [EDIT:- It was 445km to IO81RU - Steve returned a QSL card]

2)  23/5/26 GM4OAS IO75 258km. Difficult path. Thanks to Gordon being on the far side of the Highlands, this had to be entirely by aircraft scatter. Gordon suggested starting on FT8 but the Doppler was too high so we switched to Q65. You can see the steeply sloped trace on the Q65 waterfall showing the Doppler shift, which Q65 coped with well. We actually worked twice with the same plane.

QSO with GM4OAS on 23 May 2026.

3) 15/5/26 NC1I FN32 5133km. This was my first moonbounce QSO on 23cm. Frank was amazed when he heard how much power I had at the antenna thanks to my lossy coax. Of course he has a superstation with a big dish, but he still needs people to work. It was Frank who started me off on 70cm EME too. Indeed Frank started me off in all EME. I was using my 36 element yagi with no elevation.

QSO with NC1I on 15 May 2026

4) 1/5/26 LA3EQ IO28 563km. This is actually also the 5th QSO. I heard LA3EQ over a 48 hour period during a tropo lift. I worked him eight times on three bands. Although we only worked twice on 23cm, the report was +16dB and at one point he was +23. Even I cannot work someone repeatedly over 48 hours.

Above is a slice of my 23cm QSOs from my logbook. LA3EQ is a classic tropo lift/duct. This enhanced tropo propagation stayed up across the North sea for two days and at times allowed incredibly strong signals. 23cm can have superb tropo ducts. NC1I shows that you don't need a superstation or even elevation to work somebody on 23cm EME (provided they DO have a superstation at their end). The tell-tale trace off to the right on the first map above is that QSO. GM4OAS shows how aircraft scatter can cover the most tricky terrain. And G4ALG/P showed how with him running 20W we could add to a weak "dead band" path by using aircraft scatter.

FT8 might work for tropo, but Q65 is needed for aircraft scatter or EME. CW, as we are often told, is best in every situation ...

I have tried to show how I have become fascinated by 23cm. I wrongly believed that it was difficult, not taking into account how much technology has changed over my ham career. [That is a long career Jim]. Are other hams also put off by such mistaken notions from the past? How many IC-9700s are in use, maybe only on 2m as mine used to be, and are wasting their capacity to work 23cm? Could others be amazed by 48 hour tropo ducts, mind boggling aircraft scatter and EME on a shoestring? I bet they could.

What should I do next? Be content with my modest equipment? Go for high-spec coax,or a dish, or elevation, or more power, or a better preamp, or add higher microwave bands? Or all of these? I don't know. But I am thinking about it. I sometimes wonder if the best amateur radio set-ups are the ones we plan in our heads. The 23cm one I am planning is great - in my head.

23cm is just one of the five bands I use. It can be silent for days (/weeks) on end. When it opens it can be superb. 

I love the 258km QSO with Gordon just as much as the 5133km one with Frank. 

Everything on 23cm is DX compared with what I expected.

"Highly addictive" the man said. 

Do you think that I am hooked?

They tried to send me to rehab, and I said CQ, CQ, CQ. 

73 Jim

GM4FVM 

2m sporadic E

It is nice when a plan works.

On 24 May 2026 there was a large opening on 70MHz. When I say large I mean over a wide geographical area (there aren't enough active stations on 4m to make it really large). Large enough for me to work 11 DXCC and 25 stations in total on 4m. 

Total opening time on 70MHz: Four hours (so far!). 

Great fun.

70MHz as seen on DXMaps on 24 May 2026

As the 70MHz opening continued a lot of OIRT broadcast stations were heard at times. 

Some stations on 4m were +32dB and peaking S9 on the S meter. That is usually the time for me to move up my "3-band plan" and look for 2m Sporadic E.  So I called CQ on 144MHz 24 times between 10:32 and 12:51 with no result. [Keep pressing on Jim].

Then IW0RGN answered my 2m call. Out of the blue, 1771km away in JN62. We had a quick QSO with +2dB at my end and -11dB at his. I heard him call CQ one more time and the event on 2m was over for me. 

144MHz as seen on DX Maps on 24 May 2026

Total opening time on 144MHz: 75 seconds. That is the way it is with 2m Es. The searchlight covered by the signal is small, often only extending to one station. It sweeps rapidly across the map. There is usually no large scale opening as you might get on 6m or 4m. So you have to keep calling CQ in the hope that one station hear you.

And one did. 

So there. 

I noticed 12 stations in "these islands" who were copying all those CQs, Gs, EIs, GIs etc. I doubt if they thanked me for keeping appearing in their waterfalls. However, it is only by calling CQ that anyone can get DX stations to notice that a 144MHz Es opening is happening. Otherwise we all just listen and then everybody misses the whole thing.

OIRT broadcast station seen at GM4FVM 24 May 2026

So that remains the basic 3-band plan. When there is an opening on 6m with stations reaching about +0dB I will go to 4m, and when 4m reaches that level too I will try 2m. Seeing OIRT stations would provide another suggestion that 2m is worth a try, beaming to the East and South East in that case. 

At all times I will strive for the treble on all three bands, though each contact, however mundane it might appear, is welcome. 

Post Script:  The 4m opening went on eventually for nine hours. I had to stop calling toward EA as I had worked everybody there was to work. After tea I came back into the shack and found some new stations on 70MHz and worked EA4TX at 18:17 and my old pal Fidel EA1HRR at 18:18. I then had a hunch that as I was +12dB with  EA4TK on 4m it might be worth giving 144MHz another try. Once again 4m pointed the way and at 18:23 I found EA4DS on 2m at 1717km in IN80. This was followed by EA1BHB at 18:29, and he was at 1504km in IN82. That was an eight minute 2m opening. Two openings on 144MHz in one day is good going, even if they only yielded three contacts.

2m Es is difficult to find without 4m providing the clues. Openings are brief and difficult to follow. I find them hard work but rewarding. Yes, it is good when a plan works out. 

Without a plan based on the clues from the lower bands I would be lost.

73 Jim

GM4FVM

Rusty DUAL 23cm antenna restored - for a while anyway.

My 36 element 23cm Dual antenna from Antennas and Amplifiers works very well but suffers badly in the salty air blowing off the North Sea just 2 miles away. I bought it in May 2021 and by January 2023 the steel parts were rusting, though of course the boom and elements are aluminium alloy and remain in good condition up to today.

Bubbling under the coating on the 36 element Dual in January 2023

It was just getting worse over time and I knew that I would have to do something. I do not think this is structurally significant right now, but it could be in the long term. Those steel parts are very thin and will rust through eventually.

The solution I hit upon was to take it apart completely (36 bolts), clean the coating and rust off the steel parts, coat them with Hammerite paint, and then put it back together again (36 bolts). Lovely job. Cleaning the metalwork involved using wire brushes on an electric drill, just the sort of thing I do not want to do. So it took ages, not because it was really that hard, but mostly because I did not want to do it in the first place.

I am not the only person with this problem. I have heard reports of these parts rusting on other Dual antennas. I have also heard that Duals now come with stainless steel parts, apart from the boom and elements of course. Until I have seen it for myself I shall reserve judgement on that.

Eventually it got so disreputable looking that I decided I had to get stuck in.

Central section of the 36 element Dual partly completed

The photo shows the repaired side on the left and the original on the right. The mast bracket is also coated steel but I decided to leave it for now as it is not about to fall apart.

You may be wondering why I used green Hammerite. Answer: because that was the colour I could get. It should not affect the radiation pattern much.

This is not a long term solution. The Hammerite will not last too long either. 

In the meantime I fell back on my reserve 23cm antenna, the 28 element Wimo:- 

28 element Wimo

The Wimo does not look great at only 1.5m long but it is only 2dB down on the Dual and it kept me going for several months. Good enough to get across the North Sea to Norway, Sweden and Denmark plus into France, Germany and more.

The Dual is now finished and back up. It looks a lot better than the Wimo and gains me those extra 2dB.

36 element Dual restored

From ground level I cannot even spot that the steel parts of the antenna are now green.

I wonder where I will be able to work on 23cms now that this antenna has been restored and replaced on the mast?

73 Jim

GM4FVM

Blog resumes?

 OK, when I asked for comments I expected more than one email. Thanks Rick.

Two more people mentioned it in messages about other things, and two people remarked on it during conversations. Those four were not expecting it to return.

On the face of it there seems to be almost no demand for my blog. I certainly cannot keep it up as before with hundreds of postings going back over ten years with loads of links to keep up to date.

However, I am going to restart and see if anybody notices. It will be a bit different now in many ways, and just the same in others.

73 Jim

GM4FVM. 

Blog paused

The GM4FVM amateur radio blog is down at present for a re-think.

After more than 12 years it is in need of a new direction. 

If there is a demand for it, the blog may return later in a somewhat different form.

73 Jim

GM4FVM