Admirable AVO

[marconi]

When a relative’s husband died and she cleared out her loft she found an old AVO in a leather box. I don’t know how old it is but know it has not been used since her husband left the RAF In the 1950’s. ( I think it may actually belong to them!) It needed a good home so I was given it. I have not got round to cleaning it up and sorting out the missing batteries and it has just sat on the corner of my bench. Yesterday I needed an old fashioned moving coil meter to observe a voltage variation. I compared its output against my trusty skytronics DVM and to my pleasant surprise observed what I recorded in the attachment. Please excuse some of the camerawork. I guess it must be 60 to 70 years old.

ps: My first meter bought as a Christmas present in 1971 which my father was told was the Japanese equivalent of an AVO. It certainly gave sterling service until the rotary switch wore out.

Analog Multimeter TMK-500 Equipment TMK, Tachikawa Radio - https://www.radiomuseum.org/r/tmk_analog_multimeter_tmk_500.html

 

[marconi]

I’d like to move this thread away from the world of Laurence Llewelyn Bowen by asking who do we think the apprentices telectrix and pete999 employed in the 1930s might be now in the EF and why?

 

[pc1966]

Believe it or not, even into the 2000s many of the police radio transmitter sites were still using an RF transmitter with a valve as the final amplifier. Didn't look very 'valvey' though as it was sleeved with a metal heatsink. Can't remember the type.

It is still very much the case that for very high RF power levels, and/or very high frequencies (in the 10s of GHz and above, not "VHF") that valves are still the best choice in many cases.

Of course when ever you ask for the "best" choice it is very dependent on the criteria you are using for it, and the trade-off changes as technology advances, but they still have a very special place in some areas.

 

[littlespark]

I once worked at Leuchars when it was an RAF base. Doing some not very interesting mundane work in their communications centre.
3ft thick bomb proof concrete walls.

A lot of their equipment still used valves as it wasn’t able to be hacked as well as modern digital electronics could