Message-ID: <2107.200101021732@gemini>
From: "James Moritz" <j.r.moritz@herts.ac.uk>
Organization: University of Hertfordshire
To: rsgb_lf_group@blacksheep.org
Date: Tue, 2 Jan 2001 17:35:55 +0000
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Subject: LF: Happy New Year - Transatlantic
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Dear LF Group,

A happy new year to all - I have been without E-mail facilities over 
Christmas, so have just spent a couple of hours reading through 
the 260 or so e-mails that had accumulated - mostly from the LF 
group! It might take a while to digest all of it.

I didn't have a lot of time for radio things over the holiday, but like 
several others I was able to copy VE1ZZ most nights - best 
reception was during the early mornings of 25th and 26th of 
December. The limiting factor on signal quality at my QTH was 
QRN, which perversely was much higher than it had been in the run-
up to Christmas. I was quite suprised that the signal strength could 
vary as quickly as it does, sometimes 5 minutes is all the 
difference between good copy and unreadable signals.

I look forward to the tests of the 12th/13th, and will certainly be 
taking part. As far as frequencies go, the best bet as far as I can 
see for the EU side is using the bottom band edge as we did 
effectively in the autumn - provided we avoid the frequencies used 
by SXV, this should avoid interference to other users in Europe, 
and is the favoured part of the band for Canadian/USA listeners. 
The 136.5kHz frequency in use by VE1ZZ is probably OK, provided 
nobody decides to fire up on CW; but usually activity is low late at 
night. So I plan to use either 135.715kHz, or 135.916kHz 
depending on what SXV is doing, or unless somebody else 
desperately wants to use these frequencies.

Something else that would be worth clearing up is what dot lengths 
will be in use - VE1ZZ has made use of rather short dots, which 
works OK for his signal . But since he  appears to have a much 
higher ERP available than any European station, it would probably 
be best if everyone else stuck to 3s dots. In any case, it would 
help to know in advance, so that software settings can be 
optimised.

I also got my BPSK receiving gear going over Christmas- I now 
have a W&G SPM19 level meter with homebrew external 
preselector and demodulator, feeding one of G4JNT's PIC 
interfaces to VE2IQ's "Coherent" software. The SPM19 has an 
ovened reference with 10e-7 stability, and 1Hz tuning steps. The 
demodulator uses the reference output to synthesise the BFO 
frequency, maintaining the overall stability, which should therefore 
be more than adequate. I have not yet received any off-air signals, 
but loop-back tests with a signal generator and BPSK modulator 
worked fine; I am now working on the transmitter - I just hope that 
everybody does not lose interest before I get the whole thing 
finished!  I am a bit sceptical about the "Grab" feature of Coherent -
 the longer the grab length, the less random the output data seems 
to become, even with just noise being fed into the demodulator 
input.

I saw quite a few unusual modes on 136kHz; Andy's SMT-hell, what 
I presume was PSK31from DK8KW and friends, and something 
which seemed to be the key-clicks of a CW signal, without the rest 
of the signal, when looking at 136.5kHz.

I worked G3KMP for the first time on 136kHz - Colin expressed an 
interest in getting active soon on 73kHz, and being located in 
Hastings, he should be easily within range of a number of people; 
as before, I intend to be active on 73kHz on Friday evenings, if 
anyone else wants to try out their new NoVs.

Cheers, Jim Moritz
73 de M0BMU