Wednesday, 2 January 2019

The frailty of modern technology (and my ego)

Mrs FVM can certainly take a flattering photo
Katy and GM4FVM enjoying the Hogmanay celebrations.
Least said about that the better.

"Lose some weight you doughball" might be the least said then.

Moving on.

I feel that modern solid state power amplifiers are a weak point when it comes to being "brittle". They break easily. It is not surprising as we expect so much of them. We push them to their limits, we expect them to be sold a low prices and yet we also expect the highest level of reliability from them. They are generally made by the second-string producers, the big three having more or less backed out from this sector (maybe because of the reliability issues). So probably I can expect these things to have short lives and need regular repairs.

Or maybe I just break them.

Maybe I am careless with these fiddly devices. I could say that, but regular readers here know that I have had the same experience with good old solid reliable valve ones too.

Could it be my fault? Nay, surely not.

When my latest 2m linear arrived just 9 months ago and I placed the Microset SR-200 into reserve. I meant to fix it at some stage. Why did I not fix the Microset? I have just found, having a reserve that does not work is rather like not having a reserve at all.

Yes, to add to the list which already contains the 6m linear, my main Gemini 2m linear has also developed a fault. SWR trips when there is no SWR problem. As it is only 9 months old it has been packed off back to the maker and so I dug out the Microset. Surprisingly, having sat in the cupboard for 9 months it has not fixed itself.

Discussing it with John, G1VVU, he immediately suggested power starvation. Of course! Why did I not think of that. I am a chump. One of the DC supply leads looks the worse for wear. It turns out that is not the fault (John was just making a suggestion), but I certainly blamed myself for a basic error. Basic errors I can do well.

So what is the fault with the Microset? We don't know. Investigations continue. Perhaps I should put it back in the cupboard and see if another 9 months will help.

Leaning against the wall on the other side of the shack is the 6m linear. I should be fixing that too. But wait a minute, I decided to do without it for a while and working barefoot seemed OK on 6m. Why not just stick with barefoot on 2m for a while longer?

So, with 50 watts I venture onto 2m FT8 ...
144MHz FT8 contacts at GM4FVM 29 Dec 2018 to 2 Jan 2019
Well, maybe there was a bit of a lift on, but 50 watts of 144MHz seems to be OK really.

Click the images as usual if you need more detail.

I also wondered what 95 watts of FT8 on 70cms would do ...
432MHz FT8 contacts at GM4FVM 29 Dec 2018 to 2 Jan 2019
I am pleased with that. Working France on any VHF band is very good for me, but F6DBI (IN88) on 432MHz it is a bit special, and at 833km not bad on UHF in any sense. I worked the same station on 2m this week (three times actually), and I would have been happy with that. As it turned out, F8DBF (IN78 at 849km) and F6APE (IO97 at 949km) on 2m are not shabby either.

OK, I am making a meal of this. My linear amplifiers are really just here to get stations to turn their beams towards me. In almost every case, 50 watts is fine, and usually much less is enough. Living rather out of the usual line stations beam in, I find a bit more umph is handy to get them to turn their antennas and beam at me. I live in the south east corner of IO85 square, and that is not where most stations think Scotland belongs. If they are already pointing at me, barefoot is plenty.

Having no linear certainly rules out moon bounce on 2m - but I am still active on 70cms, and this past few days I have worked Germany (first time on EME) and Switzerland (first time on 70cms by any means). 95 watts - Phew! - QRO for now.

Yes I will get those linears back into action soon. In the meantime, I am very happy to go along with what I have.

Sometime I must tell you how 2 watts on HF is doing for me - rather well in fact.




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