[GreenKeys] Fredericks LEM-1

[Jim Haynes]

Well the 1280A has its ups and downs.  The display uses a plasma panel, so
if it breaks you are out of luck - unless maybe with a bit of work you can
replace it with various LED indicators.  And the frequencies are set
with the keyboard - so if you know exactly what frequencies you want
it's good, but it's not easy to just turn the knobs like you can with
the Dovetron or ST-8000.  I have one of the units, but think it is not
working correctly.  So I haven't been able to evaluate it.  The tuning
indicator is a pair of bar graphs - no worse than the crossed-LED display
but fairly hard to tune with.  There is a provision for attaching a
scope as a tuning indicator.  I'm supposed to be getting another one
soon, so hoping it works correctly and I can evaluate it properly.

There seems to have been a common specification behind a whole bunch
of demodulators: ST-8000, Frederick 1280, Dovetron, Electrocom 440,
maybe others.  Something calling for the mark and space frequencies to
be independently tunable.

jhhaynes at earthlink dot net