Steve et al...
I normally try to leave a 200Hz gap between my transmission and other
strongish ones but it is sometimes difficult to find a spot on a Saturday or
Sunday morning...
It is certainly something that everyone must consider when operating on LF,
unless you want to hear the whole band at once, use the tightest filter you
can get!
I recommend a TS850 with International Radio 400Hz filters at both IFs
allowing full use of the IF bandwidth controls... superb.
73, dave G3YXM
Over the past month, I had become aware that a certain G-station - new
to LF, but with a very commanding signal on 136.53 kHz - was often heard
to 'clobber' QSOs, and CQ calls from other stations. This puzzled me
greatly, because I knew that the station concerned could usually hear
the other stations involved.
It appeared to me - and to others - as if the station was deliberately
causing QRM to his fellow LFers.
Having recently telephoned the operator concerned, I can report that the
reason for the unintentional QRM amounted to a lack of understanding
concerning typical IF bandwidths employed by amateurs on 136 kHz. The
operator concerned is using a receiver with an effective IF bandwidth of
50 Hz (!), and he was quite happy to operate to within 100Hz of other
stations!
I advised the operator that we tend to assume a receive IF bandwidth of
250 Hz and generally aim to maintain a 300 Hz separation from other
stations. (I believe that 300 Hz has been the figure quoted during LF
Group discussions and at the LF Forum.) I hope I did the right thing.
But with the fancy new receivers now available (which I'll probably
never be able to afford!), does the Group still feel 300 Hz to be a
reasonable separation for normal CW operation?
Regards to all,
Steve GW4ALG
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