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Old February 6th 15, 10:36 AM posted to uk.radio.amateur,rec.radio.amateur.homebrew
Frank Turner-Smith G3VKI Frank Turner-Smith G3VKI is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 137
Default FM for the Eddystone EA12?

"Ralph Mowery" wrote in message
...
"Michael Black" wrote in message
news:alpine.LNX.2.02.1502051950290.19867@darkstar. example.org...
On Thu, 5 Feb 2015, Ralph Mowery wrote:
I don't have any of the very old gear, but every so often I listen to
the
hams around 3.85 MHz. that use the old military and AM gear. While I
don't think it is really legal (and don't really care) some of those AM
transmitters sound beter if I switch to FM on my Icom 746 pro. I think
when they were made they seem to put out about as much FM as AM.

That's weird. I thought those hardcore AMers wanted purity, and took
effort to ensure they were putting out a good signal. They sure aren't
using modulated oscillators, and I don't think anything where the
modulation would get back to the oscillator.

There may be two kinds of people using AM. One for 'good quality AM' ,but
the other is using mainly the military gear from around the WW2 era or so.
Maybe even before that if they can find it. That is the stuff that can
contain about as much FM as it does AM. The power supplies are often
feeding the oscillator as well as the final stages and not regulated very
well if at all. That probably helps modulate the transmitter to have a
lot of FM in the signal.

FM has always been a legal mode for 80m in the UK, it's just that nobody
normally uses it intentionally.
Provided you're using no more bandwidth than normal AM I can't see a
problem.
--
;-)
..
73 de Frank Turner-Smith G3VKI - mine's a pint.
..
http://turner-smith.co.uk