Finally able to produce a signal on 73kHz at long last!
The system is a lash-up around my normal 136kHz set-up:
- Two monster coils wound on B&Q "Fun Tubs" configured as a variometer, in
series with the 136 loading system
- Normal inverted-L antenna
- Double values for LPF in 'G3YXM' TX, running approx. 400W
- Crystal divider driver, giving spot frequency of 71.735kHz
Dave 'YXM could just hear me above the Rugby racket, which seemed very bad
last night, but we didn't bother to make a QSO. Interestingly, I can hardly
hear anything at all on 136kHz with the antenna tuned to 71kHz, so
crossband QSOs are going to be difficult with weak stations until I can
devise a way of switching out the extra loading.
Sorry I couldn't give any warning, but I only got it finished early last
evening. Anyway, sent 7 callsigns plus 'AR' on 71.735kHz from 20.00UT last
night, slow CW with 4 second dots. If anyone heard or saw anything I would
be VERY grateful for a report.
Regards John G4GVC