Hi
Re the Hans Summers 80m TX (and posibly other versions)
Tom ZL1THG was unable to get his 80m TX on frequency .
He bypassed the inductor with a short, leaving the tuning capacitor remaining.He still was at 3500.600 kHz...
This wasnt unexpected. I assume that these crystals supplied are cut for oscillation with a 30 pf load. Circuit components should give this load to acheive the rated frequency on the crystal. In this case 3.500 MHz or 7.000 MHz,, 10.140 MHz
However the frequency we want is nominally 850 Hz higher on the 80m and 40m bands. So the capacitance needs to be smaller than 30 pF.
Tom succeeded acheiving oscillation on 3500.850 kHz, by using the existing trimmer and an 8.2 pf instead of the toroid inductor in the VCXO. Depending on the crystal a larger or smaller capacitor may be needed
Kevin
ZL1UJG
