[Boatanchors] BC-639 Military Receiver

[eldim at att.net]

Hello JH & Fellor BA'ers,
Sounds good to hear of other uses. Thank for the info on the BC-640 finals.  24G = 3C24.  I always thought that was a cute tube and would look nice lit up in a cabinet.  I'll have to see if  FRANK'S TUBES has a spec sheet on them. I don't recall the filament voltage, and surely the filament current. As I play more with vintage tubes, I always have a knowledge craving as to what transformer is required to lite of the filament.  In a store you can write off the heat generated as an advertizing expense. :>)
Another thing I wonder about is a story I was once told about the origin of the BC-639 Receiver and the BC-640 Transmiter,  is that they were British designed in the late 30's.  It would be interesting to hear of it's origin and history.  I was in  (AFCS) AIR FORCE COMMUNICATIONS SERVICE from June 62 to Oct 63 and Jan 68 till Dec 72.  
73,
Glen, KA7BOJ
Tacoma, WA
eldim at att.net

-------------- Original message from jhhaynes at earthlink.net: -------------- 


> The tubes in the BC-640 were 24-Gs, IIRC. 
> 
> That experience you are citing I guess is from the days when the military 
> services were prohibited from buying any new VHF gear as a way to get them 
> moved into the military UHF 225-400 MHz band. 
> 
> I was at Edwards AFB in the early 1960s and we had a need to operate on 
> the VHF aviation frequencies as there were a lot of contractors on the 
> base and that sort of thing that were operating on civilian frequencies. 
> So we had a lot of ARC-3s with AC power supplies as a way to operate 
> those frequencies. There was a BC-640, but it was so bad that it wound 
> up at the MARS station. 
> 
> Then there was some mission they flew from time to time that involved 
> flying to Europe and required civilian VHF radio operation. So we had 
> a big suitcase full of crystals for ARC-3s that they would check out 
> whenever they needed to fly that mission. 
> 
> I was gratified to see a few years ago that the AF now has modern 
> equipment that will operate on VHF and UHF. 
> 
> 
> 
> jhhaynes at earthlink dot net 
> 
>