As I am interested on a Bitx working on 80, 40, and maybe 20 meters,
I am thinking on a Heterodine VFO and of course for the Bitx the band
switching as descrived on: http://www.phonestack.com/farhan/xcvr1.html
I am thinking of a heterodyne VFO using a oscilator from 5-5.3 more or
less, connected to the pin 1 of a NE602 acting as a mixer-oscillator
and a multy quartz crystal switched by diodes connected on pin6 of
NE602, at the output of the NE602 (pin5)there is a band pass filter
switched by diodes and finally a simple transistor as an emiter
The relation of the mix regarding that my IF value is 9Mhz is:
80meters: 7.5Mhz crystal+5Mhz Vfo=12.5
40meters: 11Mhz quartz crystal+5Mhz VFO=16 Mhz
20meters direct 5-5.5 VFO.
I think the VFO readout tunes directly on all three bands, and the SSB
is inverted but this is not a problem switching the carrier BFO
Does it look right?