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Stefan,
it is clearly visible here, abt 10dB over noise in
a 70Hz BW and even weakly audible.
73
Clemens
DL4RAJ
----- Original Message -----
Sent: Wednesday, January 11, 2012 1:34
PM
Subject: LF: QRP 1W /PA circuit
LF,
Last night i shot my PA again :-( No replacement
FETs were available so i had to stay quite during the night. Replacement parts
are ordered now and will arrive tomorrow :-)
During that time i will
run a LF beacon on 136.172 kHz running 1W TX power in DFCW-90,
starting in the afternoon. If someone can receive that weak QRPP
signal, then a report is very apprechiated :-)
Also i will do
some optimisations on my recently posted PA output stage (http://dl.dropbox.com/u/19882028/LF/DK7FC_137kHz_TX_antenna_and_PA_schematic.jpg),
just in case someone wants to build a similar design and is interested in
general:
-R= 100 Ohm/2W (In series with C, across
Drain-Source)
-C= 220pF/WIMA FKP-1 2kV (In series with R, across
Drain-Source)
-MOSFET: The IRFP460
will be replaced by a SPW20N60C3
:-)
73, Stefan/DK7FC
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