Svar till: Receiving SAQ on 24. Dec. 15

[Juergen Brustat]

Hi Bob,
I just had a look at the receive diagram on your website. You didn’t really use a 22 uH coil, did you ?
Because with a 4.7 nF capacitor it would resonate at about 500 kHz . I suppose, it’s only a typing error
and should read 22 mH, which would resonate at 15.8 kHz. The 100 k resistor broadens the selectivity curve
and when we consider component tolerances, SAQ might be well included. So far, so good, but :
the input impedance of your PC is probably not greater than a few kOhms and transformed parallel
to the tuned circuit will kill any signal received. So, I recommend using another transformer,
perhaps 100k:10k or 100k:1k, and it will work.
Instead of coil + transformer you could use a second winding on the coil only.
For testing, use the Russian Alpha signals at 12 an 15 kHz. They are much weaker than SAQ,
at least in western Europe.
Wish you good success ! DL2JMB Juergen