[Techman]

You've pretty much summed it up, David.

I had one go to full DC voltage while I was actually sat watching the radio. The 'S' meter light suddenly went a lot brighter coinciding with a strange noise on receive which broke the squelch. I instantly knew what had happened and cut the power!

I used to be very much against switch mode power supplies but, in reality, they're generally a lot safer in use than these 'old school' linear types, and RF noise supposedly generated by them isn't really a problem with them these days - BTW, I'm talking about the ones designed for powering radio equipment and not all the other noise generators that everyone has to contend with! (If I want to leave radios unattended, I've got a big old 12 volt smoothed, but unregulated unit that can never realistically go 'over voltage').

I've opened it up and it's as vile inside as it is on the outside and it still stinks like a poultry shed. In the pictures below you can see the 'add-on' board for the fan sensor, with an 'old school' thermistor, which looks of a type that's nicely familiar and has broken away from its bonding compound sticking it to the heatsink. There's also the remains of glue where the fan would have been stuck to the top of the grill cover The skeleton preset seen down in the depths looks to be the 'set voltage' adjustment of the main unit. There's a good hefty transformer with a double 117 volt primary. The unit is rated at 20 amps, so it could be useful if the smell ever leaves it. There's also still the possible fault of it cutting out after a while - perhaps that fan sensor 'add-on' circuit board incorporates some sort of cut-out? I'll have to stick a good load on it and leave it for a while to see what happens!