[time-nuts] HF frequency counting receiver

[Nick Sayer]

> On Jun 20, 2016, at 12:52 PM, Bob Camp <kb8tq at n1k.org> wrote:
> 
> Hi
> 
> The cheaters way is to simply use a fully synthesized radio tied to a known 
> reference frequency.

Yeah, that’s what I’ve got in mind. Both the synthesized tuning LO and the second LO would be derived from an external 10 MHz standard. My thought is to make a 10 kHz passband tunable in 5 kHz steps. Now, designing a receiver may be biting off more than I can chew, but that’s what I was going to try.

> Feed the output into one channel of a sound card. Feed 
> the other channel of the sound card with a known frequency tone. Post process 
> it to death with your choice of FFT programs.

Well, using the same 10 MHz standard to make a 1 or 5 kHz tone (or both) should be easy. From what you and others have said, it sounds like trying to use a TIA to read the audio frequency is a non-starter.