[Hallicrafters] SX-100

[DW Holtman]

John,

Have you removed the Sub-assembly? If you are looking at L-17 and L-18, I 
guess that you  have. The first thing that i would do is go to L-17 with an 
ohm-meter and switch to LSB and see if  a ground is applied through the 
switch S3A rear. Next do the same for L-18 at USB. If the grounds are not 
there, try a good cleaning on all of the wafer switches. If the grounds are 
good, and If you have an O-scope, you can put it on Pin 2 of V-5, switch 
back and forth to see if both crystals are oscillating. at 1600 and 1700 khz 
. If you don't have a scope, you can do the same thing with a radio that 
receives CW. Put a loop of wire around the oscillators and receive the 
signals.

Another problem is the set being very far out of alignment. The transformers 
can be so far out of alignment that it will not receive in all modes, the 
modes can be alinged so that LSB receives USB and  visa versa.

Hope that this is in the ball park and will help you get started.

Best,
DW Holtman
WB7SSN


----- Original Message ----- 
From: "John" <AI4FR at verizon.net>
To: <hallicrafters at mailman.qth.net>
Sent: Tuesday, February 22, 2005 10:13 PM
Subject: [Hallicrafters] SX-100


> Folks,
>    I am restoring an SX-100 MK1a and ran into a problem(really 2). The
> second problem is that while looking around the insides to figure out
> problem 1, I noticed that the red choke(L17 or L18), Hallicrafters part
> number 53B008 has the coating burnt nearly off. The scheumatic I am using 
> is
> very blury and I was hoping that maybe someone here can point me in the
> right direction as to where to find a replacement. This choke and another
> like it are both near the 12AT7 tube.
>
> As for problem 1? Well incase any one is interested, for some reason the
> radio does not work on SSB. As a matter of fact, flipping the AM / SSB
> switch does nothing. All of the tubes are good as well as the 
> caps(recently
> replaced). There have been no modifications that I can see except the
> addition of an SO-239 connector. When I use the on/off/treble/usb/lsb
> switch, I get audio out of the speaker in all settings except the off and
> the lsb choice. When I first received the radio, she was dead in the water
> except for one bulb that would come on. Almost as if the beast was winking
> at me cause she knew how difficult of a releationship we were about to 
> have
> :-).
>
> Thanks in advance for any help that you can toss my way.
>
> AI4FR
> John
>
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