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Old January 4th 04, 01:35 AM
geojunkie
 
Posts: n/a
Default SX-101a Operational Questions

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?

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.

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