[Hallicrafters] SX101

[Rocco Lardiere]

Mark,

I agree.  Here is a copy of what I originally sent to Bill earlier this
morning for the edification and amusement of the net.

"Bill,

The best advice I can give you is to follow the alignment instructions in
the manual very carefully.  Make sure you have the correct manual for your
radio - don't use an SX 101A manual if you have an older SX 101.

Here are some hints:

Be certain all the tubes are correct and good - it's usually a good idea to
try some known good substitutes in all positions.  Often performance picks
up.  You don't want to align to a bad tube!  And be sure to DeOxit ALL
switch and connector contacts.  Be sparing applying to the rotary bandswitch
contacts - wet only the metal, don't let it soak the wafers.  If your
bandswitch or mode switches are noisy, you need to clean them up first.
Otherwise, you can fool yourself during the alignment.  I also spray the
tube pins, straighten them, and reinsert them - this cleans up a lot of
mystery problems before I begin the alignment.  Deoxit the spring
connections to the variable cap sections rotors; if the tuning is
intermittent or scratchy when you tune through the bands, that's almost
always the problem.  If the radio is intermittent when you shift its
position from horizontal to vertical, find what is causing it.

Follow the instructions carefully.  You might want to enlarge the pertinent
pages on a xerox machine to make them easier to read.  Check the diagrams
very carefully to make sure you are adjusting the coil or capacitor that is
called out.

If an adjustment does not seem to do anything or does something you did not
expect, back off and recheck what you are doing.  If an adjustment does not
work, you may have found a real problem that needs to be fixed.   Don't
force anything - ever.   Sometimes variable trim caps in the Hallicrafters
are soldered in place at the factory.  If you see this, leave them alone and
perform the other adjustments - don't try to unsolder anything.

As for your generator - don't trust the calibration on the dial.  You can
usea counter or a modern multi mode transceiver that receives lower
frequencies for an accurate readout using a small piece of wire on the end
of a short coax jumper - a "sniffer" antenna that can be placed close to the
tube of the stage you are testing (such as an oscillator).  Usually you can
hear the frequency you are trying to maximize by laying the sniffer wire
(6-12 in.) near the radio to be tested.  I use an Icom IC 756 - it goes down
below 50 kHz and is really accurate for frequency checks.  Do NOT transmit
accidently into a sniffer antenna; disable the transceiver transmit function
(run the power to zero and unplug the key and mike).

When you do the RF alignment, do check the mechanical indexing (first step).
With the dial set at the extreme left hand stop, the pointer should be close
to the vertical indexing marks on the frequency band lines (all are in a
row, up and down).  Often someone has changed the pointer position with
respect to the main tuning capacitor.  It does not have to be perfect, but
it should be close.  Mechanical tuning should be absolutely smooth and the
pointer should not jump as you tune.

These radios are really straight forward to align, and yours will perform
much better if nobody has done one lately.  You will feel much better about
using this radio once it plays properly.  Call a local expert if you have
problems - experience counts on these things.

If you get into trouble, feel free to drop me an e mail.

73,

Rocco N6KN"