[Lowfer] Watering hole lowfers

[Garry Hess]

Doug,

I'm fortunate to have a GPS-locked 10 MHz OCXO. I drive a logic divide 
circuit with it to produce 100 kHz and 1 kHz. I input 10 MHz to my 
SDR-IQs to adjust their clock frequencies to read 10,000,000 Hz in 
SpectraVue software with AM detection. I then switch to USB, tune to 100 
kHz, and adjust the sampling rate of the Wolf GUI running in frequency 
measurement mode so the audio output frequency is correct. Since I like 
400 Hz offsets that means I tune the SDR-IQs to 99.6 kHz and adjust 
their sampling rates until I get 400.000 Hz. I use these sampling rates 
in Spec Lab. For ARGO, I adjust the "displayed frequency" calibrate 
value separately to obtain the desired 400.000 Hz value.

An alternate, direct way of ascertaining the sound card sampling rate is 
to input the locked 1 kHz signal into LINE IN and adjust the Wolf 
sampling rate to achieve a measured value of 1000.000 Hz.

-- 
73, Garry, K3SIW, EN52ta, Elgin, IL