When aligning my sets SW band I get a good signal on 18mc but the signal for 16mc falls 15.5mc. I can adjust 16 to be right on, but then my 18 signal falls short at 17.5. How do I get these spread apart to align on both as they should?

I have the same trouble on BC with 1600Kc and 1400kc.

Neal: perhaps your IF transformers are not adjusted properly. If the IF frequency is a bit too high, there will be less capacity range on the tuner and stations will be close together on the dial. It sounds like your problem. If the IF transformers are set too low, the opposite will occur and stations will be too spread out on the dial. Are you aligning by ear, or using a signal generator? If you have a digital receiver with broadcast band and shortwave you can check to see where you get a hetrodyne signal on the digital radio (should be station's frequency + the IF frequency).
Steve

Steve: Thanks for responding. I am using a signal generator. I don't have a digital receiver, but I think I will be Ok now that you've pointed me in the right direction. I suspected the IF frequency where I had the same problem on both BC and SW. Thanks again. I'll get back to you if I can't fix it.

:Neal: perhaps your IF transformers are not adjusted properly. If the IF frequency is a bit too high, there will be less capacity range on the tuner and stations will be close together on the dial. It sounds like your problem. If the IF transformers are set too low, the opposite will occur and stations will be too spread out on the dial. Are you aligning by ear, or using a signal generator? If you have a digital receiver with broadcast band and shortwave you can check to see where you get a hetrodyne signal on the digital radio (should be station's frequency + the IF frequency).
:Steve

Neal: do you have the Zenith alignment instructions for chassis 10A2? If not, I can e-mail a pdf file to you.
Steve

Steve, I do. I was going through the alignment proceedure when I noticed this problem. I'll do it again and focus on the first step (IF alignment). Maybe I'll put my fluke on the output xformer to obtain the strongest signal. I didn't tweak A,B,C,and D very far. I had my volume turned all the way up and my signal generator turned down so I didn't blast my ears out. But now I know the cause of the the problem I can focus on the IF alignment and see what happens. I expect I'll be OK. I can't do it right now cause I'm away from home. But I'll do it soon. I'll submit a follow up to let you know how it turns out.

Okay Neal. Let us know how you come out. Make sure your signal generator is fairly accurate. If you don't have a frequency counter to check it, the digital radio comes in handy to check and see where you're oscillating (455 kc IF plus the signal frequency). Without a frequency counter, I'd trust a station's frequency over a vintage signal generator. Yes, I know full speaker volume can be irriating if you're measuring output at the speaker terminals. You might also consider using the AVC line to measure negative voltage instead.
Steve

:Steve, I will get a digital radio and do as you suggested. My signal generator is fairly new. I tuned my last set with it and feel comfortable about it's output. But I need to familiarize myself with that proceedure.

Now, how do I identify the AVC line?

:Okay Neal. Let us know how you come out. Make sure your signal generator is fairly accurate. If you don't have a frequency counter to check it, the digital radio comes in handy to check and see where you're oscillating (455 kc IF plus the signal frequency). Without a frequency counter, I'd trust a station's frequency over a vintage signal generator. Yes, I know full speaker volume can be irriating if you're measuring output at the speaker terminals. You might also consider using the AVC line to measure negative voltage instead.
:Steve

Steve...I tried the digital radio thing and it turns out that if I put out 560kc on my signal generator, I get 560kc on the radio. Same accross entire band. Must be because it's an RF signal generator? Anyway it's real close, maybe 5kc difference.

:Okay Neal. Let us know how you come out. Make sure your signal generator is fairly accurate. If you don't have a frequency counter to check it, the digital radio comes in handy to check and see where you're oscillating (455 kc IF plus the signal frequency). Without a frequency counter, I'd trust a station's frequency over a vintage signal generator. Yes, I know full speaker volume can be irriating if you're measuring output at the speaker terminals. You might also consider using the AVC line to measure negative voltage instead.
:Steve

That's fine for checking your signal generator. But the real issue is where your Zenith's IFs are set. Tune the 10-S-589 to a strong AM broadcast station of known frequency, and see if you can zero-beat the station's frequency plus the IF frequency where you would expect it. For example, if the AM station is transmitting on 1200 kc (yea, I know guys - I'm showing my age), then you would expect to receive a strong signal on 1655 kc (IF + signal frequency) while holding the digital receiver close to the Zenith. If you rock the tuner a bit, you should be able to hear the squealing signal go up in pitch on either side of a null in the middle. The null is what we call "zero-beat". Hopefully your digital receiver is able to tune 1 kc increments and is not limited to 10 kc am channel spacing increments.
Steve

Okay Steve....thanks for your patience with me. I think I can get it right this time. The digital radio that I came up with goes in 10kc increments so I will find one that goes in 1kc increments and try again. Unfortunately I'm away from my set again until tomorrow. I've got a good strong station to work with on 820kc.

:That's fine for checking your signal generator. But the real issue is where your Zenith's IFs are set. Tune the 10-S-589 to a strong AM broadcast station of known frequency, and see if you can zero-beat the station's frequency plus the IF frequency where you would expect it. For example, if the AM station is transmitting on 1200 kc (yea, I know guys - I'm showing my age), then you would expect to receive a strong signal on 1655 kc (IF + signal frequency) while holding the digital receiver close to the Zenith. If you rock the tuner a bit, you should be able to hear the squealing signal go up in pitch on either side of a null in the middle. The null is what we call "zero-beat". Hopefully your digital receiver is able to tune 1 kc increments and is not limited to 10 kc am channel spacing increments.
:Steve

Neal: personally I wouldn't waste any money to buy one for just this purpose. I only suggested using one if it was readily available. I think your money would be better spent on a good used frequency counter that can be had on eBay for around $30. First I would try the alignment procedure again using your signal generator. You can check the second harmonic of your signal generator set to 455kc (fundamental frequency) by listening to your digital receiver at 910 kc. Rock your signal generator frequency knob till you "zero-beat" the harmonic signal on your digital receiver at 910 kc. Now you'll know where 455 kc is exactly on your signal generator. I usually use the speaker output volume and an analog volt meter (set to the 5v or lower AC scale and connected to your speaker leads) to do alignments, and seldom use the avc line but either method is fine. On the alignment of your Zenith, when adjusting trimmers A,B,C, and D, set your signal generator to the minimum output necessary so you can just hear the modulated tone in the speaker with volume control at max. Normally alignment should start with the last adjustment in the signal chain, and go backwards to the first, or antenna end of the chain. Make sure your Zenith is warmed up and stable before doing the alignment. Zenith's instructions simply mention trimmers A,B,C, and D (A & B are on the first IF, and C & D are on the 2nd IF). I don't think it's all that critical which is done first since adjustments are rather self-correcting, but start with the output IF and adjust C & D for maximum volume and max ac meter reading. Turn the screws backwards and forwards through the position of the loudest note, finally ending with a tightning motion at the loudest volume (max voltage reading). Before making the next adjustments on the input IF, use the signal generator's attenuator to reduce the tone volume, and proceed as before looking for the max volume and greatest meter reading (you may have to lower the meter's voltage scale for max sensitively). That should put your IFs where they should be, and proceed with the rest of the alignment from there.
Steve

Steve...I want to familiarize myself with the digital radio scenario. As you could easily tell, I have a lot to learn. But I'll put that on hold until the right digital radio comes up and follow your most recent instructions. I'll keep my eye out for a frequency counter also. Now all I need to do is get back to my set an implement. I want to learn about that AVC -voltage method too. Much help has come and I'm stuck on afternoon shift at work away from my set. I appreciate your help and I will surely keep you posted as I go along....Neal
:Neal: personally I wouldn't waste any money to buy one for just this purpose. I only suggested using one if it was readily available. I think your money would be better spent on a good used frequency counter that can be had on eBay for around $30. First I would try the alignment procedure again using your signal generator. You can check the second harmonic of your signal generator set to 455kc (fundamental frequency) by listening to your digital receiver at 910 kc. Rock your signal generator frequency knob till you "zero-beat" the harmonic signal on your digital receiver at 910 kc. Now you'll know where 455 kc is exactly on your signal generator. I usually use the speaker output volume and an analog volt meter (set to the 5v or lower AC scale and connected to your speaker leads) to do alignments, and seldom use the avc line but either method is fine. On the alignment of your Zenith, when adjusting trimmers A,B,C, and D, set your signal generator to the minimum output necessary so you can just hear the modulated tone in the speaker with volume control at max. Normally alignment should start with the last adjustment in the signal chain, and go backwards to the first, or antenna end of the chain. Make sure your Zenith is warmed up and stable before doing the alignment. Zenith's instructions simply mention trimmers A,B,C, and D (A & B are on the first IF, and C & D are on the 2nd IF). I don't think it's all that critical which is done first since adjustments are rather self-correcting, but start with the output IF and adjust C & D for maximum volume and max ac meter reading. Turn the screws backwards and forwards through the position of the loudest note, finally ending with a tightning motion at the loudest volume (max voltage reading). Before making the next adjustments on the input IF, use the signal generator's attenuator to reduce the tone volume, and proceed as before looking for the max volume and greatest meter reading (you may have to lower the meter's voltage scale for max sensitively). That should put your IFs where they should be, and proceed with the rest of the alignment from there.
:Steve

Steve...reporting back with much success. I sat the digital radio near my set and tuned it to 910kc. It had a handy am antenna. (loop type) I adjusted my signal generator to 455kc and put the probe inside the loop antenna. I rocked the signal back and forth and there it was, the second harmonic. I rocked the signal in then out, in then out, looking for the "zero-beat", and there it was dead center between the 2 rocked signals. And it was just a tad higher than the mark on the signal generator!!

Then I started the alignment process. I used the -avc voltage method in order to use the info that radiodoc and edd gave me. SW went perfectly with 18mc and 16mc coming out right on the money. BC went well on both 600kc and 1500kc coming in perfectly. 14kc was a little off, but what the heck. I was picking up stations I couldn't get on the digital!!

I have a couple of paper caps yet to change and a few more strands of brittle wire insulation and then I'm going to do it again just cause I can.

I've got a bid on ebay for a frequency counter. How can I thank you enough. I guess, just thank you for your time and talent.....Neal

:Neal: personally I wouldn't waste any money to buy one for just this purpose. I only suggested using one if it was readily available. I think your money would be better spent on a good used frequency counter that can be had on eBay for around $30. First I would try the alignment procedure again using your signal generator. You can check the second harmonic of your signal generator set to 455kc (fundamental frequency) by listening to your digital receiver at 910 kc. Rock your signal generator frequency knob till you "zero-beat" the harmonic signal on your digital receiver at 910 kc. Now you'll know where 455 kc is exactly on your signal generator. I usually use the speaker output volume and an analog volt meter (set to the 5v or lower AC scale and connected to your speaker leads) to do alignments, and seldom use the avc line but either method is fine. On the alignment of your Zenith, when adjusting trimmers A,B,C, and D, set your signal generator to the minimum output necessary so you can just hear the modulated tone in the speaker with volume control at max. Normally alignment should start with the last adjustment in the signal chain, and go backwards to the first, or antenna end of the chain. Make sure your Zenith is warmed up and stable before doing the alignment. Zenith's instructions simply mention trimmers A,B,C, and D (A & B are on the first IF, and C & D are on the 2nd IF). I don't think it's all that critical which is done first since adjustments are rather self-correcting, but start with the output IF and adjust C & D for maximum volume and max ac meter reading. Turn the screws backwards and forwards through the position of the loudest note, finally ending with a tightning motion at the loudest volume (max voltage reading). Before making the next adjustments on the input IF, use the signal generator's attenuator to reduce the tone volume, and proceed as before looking for the max volume and greatest meter reading (you may have to lower the meter's voltage scale for max sensitively). That should put your IFs where they should be, and proceed with the rest of the alignment from there.
:Steve

Wonderful! Glad that Zenith is working better now. Usually it's best to align after all the caps are replaced, but at least we know why the stations were bunched up now. What's the next project??
Steve

The next project is to finish cap replacements and brittle wire replacements. Then I'm going to align it one more time.

I also want to go back to my Zenith 7S682 and realign it. I feel like I can get a better result with the new things I've learned.
Neal

:Wonderful! Glad that Zenith is working better now. Usually it's best to align after all the caps are replaced, but at least we know why the stations were bunched up now. What's the next project??
:Steve