LF: DK7FC Report [Was QRP 1W /PA circuit]

["Dave G3WCB." <ganymede444@btopenworld.com>]

Stefan,

 

A trace of your signal visible here tonight. See attached.

 

73, Dave G3WCB IO91RM

 

 

-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org]On Behalf Of Chris 4X1RF
Sent: 11 January 2012 21:52
To: rsgb_lf_group@blacksheep.org
Cc: Stefan Schäfer
Subject: Re: LF: QRP 1W /PA circuit

Stefan,

Signal clearly visible in YO: http://dl.dropbox.com/u/10280270/yo4x1rf_DK7FC_QRP_1w_11jan2012.jpg


73s
Chris 4X1RF

2012/1/11 Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>

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

DK7FC_2200z_11_Jan_2012.jpg
Description: JPEG image