[ARC5] Selectivity improvement in BC-639

[Kenneth G. Gordon]

On 2 Jun 2014 at 12:49, Jack Antonio wrote:

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

Makes sense...
 
> 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)?

Hmmmm......good question, to which I have no answer.

>  > 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".

Wow! 140 kHz.! No wonder Jeep wants to improve it!

Ken W7EKB