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Stefan
>If someone
wants to report about the signal, it is welcome :-)
Jay W1VD WD2XNS WE2XGR/2
----- Original Message -----
Sent: Monday, January 16, 2012 6:43
PM
Subject: LF: Beacon to the west... /
TA
Hello LF group,
After a break of 2 days on LF, which is
VERY long for me, i am back on about 136.172. I've done various changes on the
circuit and even use another VFO (the DDS is used in the first VLF
experiments). It is running on batteries and i just opened the windows to the
shack so there may be a little drift.
I'm back with -3 dB f.s. and its
frozen outside! :-)
This is the last pair (4 pcs.) of FETs and i will go
back to the IRFP460 then. However i found there is also a IRFP460A
which looks a bit more suitable for such critical switch mode applications.
I've already ordered 20 pcs of them ;-) The FETs i'm using right now have rise
and fall times below 10 ns which may be even worse in this application. But
maybe the actual reason why they blow up is a completely different. Thus i
will test the DDS now (no phase glitches)...
If someone wants to report
about the signal, it is welcome :-)
73,
Stefan/DK7FC
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