[Hallicrafters] RTMA Dummy Antenna needed for alignment?

[Roger D Johnson]

The whole idea of the dummy antenna was to align the input
of the receiver with the "standard" 50 to 100 ft wire
antenna most listeners used in the old days. Most of the
regular receivers did not have an antenna trimmer and this
was a compromise adjustment that generally gave good results.
Most of the high end "communications receivers" of old were
designed for an input impedance of 300 to 450 Ohms or so.
Most of these would benefit from using a 4 to 1 or 9 to 1
step-up transformer on the input. I normally just use the sig gen 
directly and have never noticed poor sensitivity due to the
impedance mismatch. Of course, the later receivers were designed
for a 50 Ohm input and should be aligned with a 50 Ohm source.

Regards and 73, Roger

-- 
Remember the USS Liberty (AGTR-5)
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