Sounds good Roger and Graham... what it the stability like the problem with
transverters/upconverters normally is that while ok for some modes they are
often not stable enough for the very weak signal modes. These are modes where
you need to know the frequency of a station very accurately because you will
not hear it, or it will only pop above the noise for short periods.
Alan G3NYK
--- On Wed, 9/12/09, Graham <[email protected]> wrote:
> From: Graham <[email protected]>
> Subject: LF: 500kHz simple 5W TX/RX transverter >>DATA MODES<<
> To: [email protected]
> Date: Wednesday, 9 December, 2009, 22:13
>
>
>
>
>
>
>
> 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 :-
>
>
> http://groups.google.com/group/uk500khz/web/meat-grinder-comms
>
> G..
>
>
>
>
> From: Roger
> Lapthorn
> Sent: Tuesday, December 08, 2009 12:20 AM
> To: [email protected]
>
>
> 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
> --
>
> -------------------------------------------------------------
> http://g3xbm-qrp.blogspot.com/
> http://www.g3xbm.co.uk
> G3XBM
> GQRP 1678 ISWL G11088
>
>
>
>
>
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