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All
This latest addition to the
HF / MF tx convertor opens the door to data
communications on 500 ... ranging from 'all' the K1JT systems
through to the single carrier
multi tone systems of
MFSK , DOMINO and THOR .. even the almost
forgotten Amtor-arq and Packtor modes , anyone still have
there pk232
listed are
data modes that may be used with non-linear systems :-
G..
Sent: Tuesday, December 08, 2009 12:20 AM
Subject: LF: 500kHz simple 5W TX/RX transverter
Dear All,
My WSPR tx up-converter has now been modified to
a full TX/RX tranverter suitable for WSPR, QRSS and CW in a
very simple way, making use of the FT817 split facility which allows you
to RX on 500kHz and TX on 28MHz. By adding a series LC between the TX PA and the
FT817 input/output RF connection (with back-to-back diodes at the L and C
junction, this allows "pass through" from the 500kHz ATU to the FT817 on RX
(tuned to 500kHz). On TX, the diodes conduct and the C part is in parallel with
the first cap in the TX low pass filter. This scheme is now working really well
with good RX sensitivity and no change in TX power out.
Schematic of the
transverter is on my blog at http://g3xbm-qrp.blogspot.com/ . My
attempt to add it as an attachment to an email here earlier failed.
This more or less concludes my 500kHz experimenting, apart from
getting a few more CW QSOs in the log. It's been great fun all the way with lots
of support from folks here. I was going to try 136kHz, but think I will now give
this a miss for now.
73s
Roger G3XBM
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http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
G3XBM
GQRP 1678 ISWL G11088
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