RadioBanter - View Single Post - Hallicrafters SX-42 Alignment

August 3rd 03, 04:32 AM

In article ,
(Ed Engelken) writes:

It is possible to get the local oscillator (LO) set on the wrong side
of the signal frequency when aligning the higher frequency bands. If
you get the LO on the high side of the signal frequency on one end of
the band and on the low side on the other end, the calibration and
sensitivity will never be good.

Very good advice, and a common cause of trouble with single-conversion rx.
Such cross-alignment can also cause self-oscillations and/or totally dead spots
somewhere on the dial.

Another way to check for this error is to flip the signal generator (or the
radio) to the expected image frequency, and verify that the image is on the
same side of the "real" frequency at both ends of the dial. Many receiver
manuals mention this check.

I have the SX-42 docs but not real handy. Something to look forward to when I
try to get my '42 up to snuff (it is almost deaf now, but works on all bands
and modes).

Are there still any commercial mobiles on the 30-50 MC FM band?
73, Mike K.

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