I am working on a Hallicrafters s-120 that I have had around for a while. I did a full recap on this unit and replaced the selenium recifier with a diode a while ago. I put it aside when I noticed that it appeared to be WAY WAY out of alignment but decided recently to try it again...

I have gone through the alignment procedure as stated in the schematics. I can't get it going right....

I can tweak this thing to pick up the local AM station that is about a mile from my house but nothing else. When I align it per the instructions, I get no reception at all when I am done with the alignment.

My question is what could be doing wrong? Is there a point where you should start with all of the trimmers and slugs in a certain position when you have something so out of alignment? It seems like the best I get it is when all of the slugs in the IF cans are bottomed out. This does not seem right to me. Has anyone ever done one of these before that can give me some advice?

I have done tons of alignments with great success but this one is a bear....

Hi

Check that the oscillator is operating. It's possible to receive a station and not have the oscillator working.

Look at the osc with a scope or listen to a second radio tuned the IF frequency above your S-120.

Do you have a signal generator to set IF frequency? Shouldn't have to bottom slugs to get a signal.

Norm

:I am working on a Hallicrafters s-120 that I have had around for a while. I did a full recap on this unit and replaced the selenium recifier with a diode a while ago. I put it aside when I noticed that it appeared to be WAY WAY out of alignment but decided recently to try it again...
:
:I have gone through the alignment procedure as stated in the schematics. I can't get it going right....
:
:I can tweak this thing to pick up the local AM station that is about a mile from my house but nothing else. When I align it per the instructions, I get no reception at all when I am done with the alignment.
:
:My question is what could be doing wrong? Is there a point where you should start with all of the trimmers and slugs in a certain position when you have something so out of alignment? It seems like the best I get it is when all of the slugs in the IF cans are bottomed out. This does not seem right to me. Has anyone ever done one of these before that can give me some advice?
:
:I have done tons of alignments with great success but this one is a bear....

Thanks Norm,

I'll check the oscillator. I do have a freq generator and I set it dead on 455 as checked with my counter.

:Hi
:
: Check that the oscillator is operating. It's possible to receive a station and not have the oscillator working.
:
: Look at the osc with a scope or listen to a second radio tuned the IF frequency above your S-120.
:
: Do you have a signal generator to set IF frequency? Shouldn't have to bottom slugs to get a signal.
:
: Norm
:

The oscillator appears to be functional as I can get the squeal from it on my reference radio as suggested.

Is there a general rule of thumb for starting all the trimmers out at a certain spot and then aligning from there? I am ready to throw in the towel on this one and make it a parts set....

Hi

Since you have a signal generator try setting the IF frequency first. You might be trying to align the IF Transformers on a harmonic? You shouldn't be all the way at one end of adjustment. Can you find another peak, more to center of adjustment?

Norm

:The oscillator appears to be functional as I can get the squeal from it on my reference radio as suggested.
:
:Is there a general rule of thumb for starting all the trimmers out at a certain spot and then aligning from there? I am ready to throw in the towel on this one and make it a parts set....

I have the same problem with mine. Where do you connect the scope to check the oscillator? I get a couple of stations, does that mean my oscillator is working?

Richard

The oscillator is operating if you are able to tune stations. Without the oscillator a radio is sometimes able to receive a strong station or stations mixed together. The tuner will act more like a volume control in this case.

Norm

:I have the same problem with mine. Where do you connect the scope to check the oscillator? I get a couple of stations, does that mean my oscillator is working?

^
:Richard
:
: The oscillator is operating if you are able to tune stations. Without the oscillator a radio is sometimes able to receive a strong station or stations mixed together. The tuner will act more like a volume control in this case.
:
:Norm
:
::I have the same problem with mine. Where do you connect the scope to check the oscillator? I get a couple of stations, does that mean my oscillator is working?

I can pick up other stations where they should be on the dial but they are very very quiet and generally only the 50k watters. I have to have my ear on the speaker to hear them. The local comes in very loud and a couple others come in at decent volume.

Back to my original question, is there a general rule of thumb as to a starting position for all slugs, padders trimmers etc when aligning a set that is way out of whack? Also, has anyone worked on one of these Hallicrafters that has any pearls of wisdom.

Before it goes to the parts pile, I am going to check every resistor to see if I have any problems there....