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Mal,
we have here a unit W&G SPM 12 that run 24 hours at day
used for our relay LF to 2 meters FM, the filters used is the 1800 HZ, without
AGC, and powered from a 12 VDC voltage battery, in this way also without the AC
line the syntetizer dont lost the frequency tuned.
For me work very well, all the signal received with my 80
metrs vertical and IC737 with converter, are also on SPM 12 with a 40 metrs high
vertical located on a 600 meters high hill and retrasmitted in 2 meters
FM.
The stability for qrss 3 is excellent.
For me this is an excellent receiver, bought here few mounths
ago in hamfest for 180 Euro.
73 Giulio Ik2DED.
In spite of what some say this device is very
stable, but I use it inside in a fairly constant temperature, not outside in a
garden shed.
AGC is not necessary. On LF it is more desireable
not to use agc, otherwise static takes over to the detriment of weak signals.
Tuned to various signals during the weekend, all
signals stayed within the 20 hz bw. It works well.
All signals were monitored on speclab and argo.
Someone said they preferred a 300 hz bw.
How can anyone work with this sort of bw on LF !!!!!
and hear the very weak signals. I now know why I
hear dx stations calling some UK station, that do not reply !!!!! They
obviously do not have the optimum signal over noise with a 300 hz
bw.
I listened and watched the recent Russian signals
on both the Siemens and W&G and had no problem with stability. I saw no
wobble of variation at all.
Another point. Dont switch your pegelmesser on
and off each time you use it. Leave it on all the time to stablize the
oscillators, mine stay on for weeks at a time. On commercial radio stations
all equipment is left on 24 hrs each day and every day of the year.
The W&G spm-12 is synthesized.
73 de Mal/G3KEV
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