[ARC5] HF Converter - feeding mixer with a square wave?

[Leslie Smith]

Good-day Tom & others:

A suggestion has been made: Harmonics found in the LO signal will mix with
'out of band signals' to create spurs.  An obvious example would be:
   Signal - 3x LO -> IF frequency.
    10.000 - 3x 3.2 -> 400kHz

Since the BC-453 has an accurate dial and a 10MHz signal is easily found a
test rig can easily demonstrate the proposal above.  The desired 80m signal
would be at 3600 kHz.

I propose to build this circuit using a 2n3819 + some sort of binary
divider.  I'm thinking a 4027 JK FF.  Alternately, other frequencies might
be tested:
    1512(kHz) - 3x 400 -> 312(kHz)
This is a conveniently done here at my QTH.  ABC Radio National broadcasts
on 1512 locally.  Other nearby stations (both weak and strong) will provide
more test signals.

Once this has been done, I can test Wayne's suggestion of feeding a
sine-wave to the mixer at the frequencies listed above.

Leslie
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20220318/72fa2b88/attachment-0001.html>