[ARC5] Selectivity improvement in BC-639

[Jack Antonio]

On 6/2/2014 12:08 PM, Kenneth G. Gordon wrote:

 > Jeep: I am very curious why you would consider doing that to that 
receiver? It
 > covers 100 to 156 MHz, and as I recall, is not particularly sensitive 
in that
 > range, nor very stable either.

The BC-639 includes a BFO, but on mine,the beat note against a stable
source (local ATIS) is very unstable.

So I wonder, what was the purpose of the BFO, was there ever any intent
for CW use on VHF(actually called UHF back then)?

 > Indeed! They are very broad. I forget exactly how broad but I think 
it was
 > something like 30 KHz.


According to the book:  "140,000 cycles at 6db down".

Jack Antonio WA7DIA/4