"geojunkie" wrote in message
om...
This SX-101a is my first HAM-only receiver, and has some features new
to me such as a product detector. I have spent many hours recapping
and aligning it, and pretty much all is well, but I have questions
about what is "normal" for this unit:

For AM reception you must listen to either the upper or lower
sideband, unlike my SX-71. I notice that no matter where the
selectivity is set (2,3 or 5 khz) that I must retune when switching
between sidebands. It is like the spread of the side band oscillator
crystals is a bit wider that the selectivity. I must tune lower up a
bit or upper down. Is this normal? If not, how can I close this gap a
bit?

I notice that the S/N ratio seems poor. There is always a lot of
background rush (kinda like white noise) compared to the SX-71. The
alignment process makes no reference as to what is normal. Even with
antenna terminals shorted there is still some noise, not
insignificant. How can I measure to see if this is within spec, and if
not, what might be the culprits?

Do the signals really jump out of the backround noiise, or does it seem
like the radio is half deaf? I don't know the SX-101, but in general, a
very sensitive radio might very well have a significant amount of
backround noise. Of course, if the sensitivity seems low, you will have
to do some basic troubleshooting. The RF amp and the mixer are the main
suspects.

Be sure you didn't miswire anything when you recapped it. I'd like to
say such things never happen, but I miswired a ratio detector after I
fixed a bad connection at it's internal mica cap a couple of days ago.



I could not get 15 meter band to align... no matter how slug and
trimmer were adjusted I could not get the full bandspread as shown on
the dial. All other bands were fine. What might I look for to correct
this? I set 21.3mhz right on but both ends come up short of dial
setting.

The oscillator may be on the wrong side of the signal. If it's above
the signal, try setting it below the signal. Or vice versa. Don't
expect the oscillator to be on the same side of the signal as the other
bands.

BTW, for now my antenna is a 10ft wire, but that is what I was using
on the SX-71 which is my only comparison reference. Perhaps the 101
needs more antenna to sound good??? Any and all advice appreciated as
always.

Dan

Again, I don't know the 101, but I'd expect it to be considerably more
more sensitive than the run of the mill Hallicrafters radios such as the
S40A, which will start to work with a clip lead on the antenna terminal.

Frank Dresser