[Hallicrafters] SX-101A Dial Adjustment Help

[Rocco Lardiere]

Frank,

Perform  receiver alignment per the manual.  That's the best thing to do,
even if you need to find equipment and get some local help.

If the problem is on all bands, it's possible that the pointer on the dial
cord has slipped or been moved intentionally or it is badly misaligned
electrically.  The pointer should have overtravel in both directions, beyond
the band edges.  It's best and easier to leave it alone and adjust the local
oscillator trimmers properly per step 5 in the alignment instructions.   A
slipped pointer could do that - but that's a long way to slip.  You should
check the dial indexing - the pointer should line up with the five vertical
dial lines on the far left of the readout when the tuning cap gang is fully
closed (should hit the mechanical stop) (see p. 15 in the manual).  The
pointer reset should be centered for this check.  If the mechanical indexing
is approximatly correct, you have an electrical alignment problem, which is
actually easier to fix.  As the manual says, check the mechanical indexing
first and then move to the electrical frequency adjustments.

If the problem is only on 20 meters, or perhaps one or two other bands, it
is likely that someone got in there and twiddled away at the local
oscillator adjustments without understand what he was doing (very common!)
Alignments are not that difficult, at least the RF part.  Read the manual
and adjust L16 per step 8 - that affects 20 m only, and you should be able
to walk in the frequency (center the pointer reset when you do this).  Be
careful to locate L16 - don't touch anything else unless you KNOW what it is
and understand the alignment instructions for it.  Note that C58, the
associated LO cap, is soldered in place on many if not all of these
receivers, so don't try to adjust it, even though it is called out in the
manual.

Best thing is make sure you have good tubes in there, clean the switches and
pots with DeOxit and perform the entire alignment, if you feel comfortable
doing it.  You may be surprised how much better the receiver performs!

Hope this helps - these receivers are actually easy to work on, with plenty
of room.  The hardest part of all this is getting the receiver out of the
case without scratching or breaking anything, such as your back.  I think I
remember that there are access holes in the bottom of the case to get at L16
without taking the cabinet off; that's a good thing, because the cabinet can
affect some of the LO adjustments (though not much for this receiver, if I
remember correctly.)  It's best to take it out and inspect for dirt,
spiders, etc.

73,

Rocco N6KN
----- Original Message -----
From: "Frank Baker_new" <frankbaker at mchsi.com>
To: <hallicrafters at mailman.qth.net>
Sent: Sunday, March 09, 2003 2:34 PM
Subject: [Hallicrafters] SX-101A Dial Adjustment Help


> Hello:
>
> I recently acquired a SX-101A. The problem I have is that the Pointer rest
> does not have enough travel to center on the correct frequency. It's
around
> 100kc's low. For example 14.200 is actually 14.260  using all the pointer
> adjustments. Please send me the method to adjust if you have ran across
this
> problem before
>
> 73's Frank
>
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> List Administrator: Duane Fischer, W8DBF **for assistance**
> dfischer at usol.com
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