Tuesday, January 5, 2010

80m QRSS RX, TX or TRX

Some thinking came to my head lately... (ouch!). The 20m + 10.4MHz down conversion is a nice attempt. However, for a quick fix, there is another option.
Wrap your head around this:

  • 9.600MHz (modulated) oscillator
  • 6.000Mhz down conversion LO


  • 9.600MHz local oscillator
  • 6.000MHz crystal filter
  • 3.000MHz subharmonic BFO
  • or a 6.000MHz BFO (e.g. w/ NE612)

Now, seeing it, I think 3.5999MHz should be the natural choice anyway, since all crystals involved are off shelf standard....
For reasons of performance I would prefer subharmonic mixing. Simplicity, however, would be found in a single 6MHz oscillator approach.

Hmmm, if only I got the energy to build all my concepts....