From HB9ASB, JN36pt
Here I've still troubles with my PC (seems to be a Monday device), so
I'm back to the most reliable mode and only qrv in normal CW.
But with a little bit more power from a new TX. A G3YXM design with the
following variations: Vackar VFO on 6.8 MHz and 4*IRFP250 supplied with
35V/20A.
So far I've made very good experience with the Vackar (I also used it in
my former TX): If temperature compensated it has a good stability,
acceptable for SlowCW. Anyway, next project is a DDS.
The IRFP250 is very robust (and it handles much more current than the
IRFP450) and so far they survived every mismatch.
Only protection circuit is an overcurrent protection at 25A, realized
with a sensing transistor over a shunt, instead of the hall element.
It triggers a Flip-Flop and stops the driver until reset.
Unfortunately I am probably now also in the crocodile class: In the past
few weeks I've heard often stations, probably calling me, but I couldn't
copy them. Especially in QRN caused by "electric" snowfall. Please give
me long calls (your call only) so that I get the chance to adjust the
receiver and Audio-DSP.
Last Sunday I could also receive PA2NJN - he was very strong - about the
same as DF2PY. But both are probably also in the crocodile league, hi.
Paul, HB9DFQ is now also QRV in Slow CW and I'm trying to get Bert,
HB9DCE on this mode. Bert has a very good receiving situation and hears
probly better than me. They have both approx. 100W RF and good antennas.
Paul is located near Zurich and Bert near Winterthur, 150km NE from my
QTH.
Sorry for all those stations I missed in the past weeks - we will try
again.
73 de Toni
|
