FM Transmitters...

Assuming they still exist and are interested. Have you ever looked at the cost of refurbished ordinary ham radio transmitting valves capable of half a kilowatt?

Not that I have, but I hear that new ones are often crap since the Chinese never really test them and the assemblies can be poor quality in plating and construction, but there aware still some big triodes around ex Russian military that can be pressed into use and the only issue is supplying the heater current of several amps.

Brian

The signal on 252 is compromised by another station these days, sadly. That transmitter was as I'm sure folk know a semi legal commercial outlet trying to gain access to the uk market but eventually closed and the transmitter taken over by RTE. Its nowhere near as strong as radio 4, I guess in the age of the internet it will eventually close, but the fact is that internet is not a radio station, its reliant on the good will of those who own it to keep it running in all weathers and natural disasters and wars, which of course I feel is pi in the sky, since communication channels are the main target in any war.

Brian

They tend to have redundancy built in, and many seem to use hot swappable modules and PSUs these days, so you can replace failed ones while still continuing to operate.

Many of the UHF DTT sites are using IoT 'valve' based transmitters, they were installed about about 10 years at DSO

Is the valve used specific to the frequency transmitted or could we buy valves from long-wave transmitters that are closing down?

In article <rurf1e$9l7$ snipped-for-privacy@dont-email.me, Brian Gaff (Sofa) snipped-for-privacy@blueyonder.co.uk> scribeth thus

This does seem the way of it they have reduced the TX power in order to save some money. I think the equipment is OK and whilst the broadcaster is wanting to move listeners to other mediums theres a diehard Irish population especially in the North West of England oddly enough who can still receive it on an ordinary transistor, possible valve! wireless and they can get it in their cars.

It is receivable down here in mid Anglia and its nice to have a brief listen from time to time to the land of my descent!, an all 'n all:)...

In article <rurehp$6fb$ snipped-for-privacy@dont-email.me, Brian Gaff (Sofa) snipped-for-privacy@blueyonder.co.uk> scribeth thus

We look after a small DAB system that comprises of a modulator thats running a bit of free open source software on a small NUC machine. That drives a small universal software programmable driver unit. The output of that goes to a linear Class A power amp of a 100 watts capacity thence to a sharp passband filter and then to the aerials.

All there is to that bigger systems will have a somewhat more elaborate mod and driver and a larger amp system by makers such as Rodent and Black in Germany!

In article <rurep1$7r1$ snipped-for-privacy@dont-email.me, Brian Gaff (Sofa) snipped-for-privacy@blueyonder.co.uk> scribeth thus

Dunno about vales for Ham use but the prices they charge for much bigger valves will have a shade more care lavished n them!..

Here you go, for a look at the place that uses them excellent PDF called Droitwich calling here worth a look!...

Indeed they did bit they seem to be out of fashion these days, the LDMOS rules!...