Help!!!

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Re: Help!!!

Post by 75X11 on Thu Sep 04, 2014 6:37 pm

If they don't already have a reference, You might put a line on the outside of your tools to give you an idea of how many or how far you have turned them. I'll let the 'tweakers' give you alignment instructions. Very Happy
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Re: Help!!!

Post by frank1956 on Thu Sep 04, 2014 7:43 pm

I had no luck Sad  with the alignment. I tried the 2nd IF can starting from the bottom, could not even get the needle to move on the analog meter scratch scratch Turned it ever which way with no luck either bottom or top. I am pretty sure I following the advice/instructions given to me. 1st IF can top portion will not even turn, not sure if it maxed out in turns, frozen or what the deal is. Started at 5:30 just now finishing up.

Thanks for the advice on the tools I will mark them as I use them.


Frank
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Re: Help!!!

Post by jerryhawthorne on Thu Sep 04, 2014 8:09 pm

This many pages into it can anyone post the schematic and instructions? The posting on the first page I can't open, I guess I don't have the right reader.
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Re: Help!!!

Post by Wildcat445 on Thu Sep 04, 2014 9:39 pm

Frank, try this. Determine what type of adjusters you have. Commonly they will either be slotted or hexagon shaped.

With the radio off and unplugged, and using your pocket screwdriver, make sure the alignment slugs will turn. Sometimes they get stuck over time. Plastic tools may not want to turn them. So get them to move with a metal pocket screwdriver. Do this like adjusting a carburetor, just a fraction of a turn at a time. Like a quarter turn. Fairly gingerly at first until you get it to move. If your set has hex shaped adjusters, get an Allen wrench and turn them. Freeing them up first will make adjustment easier.

Jerry, I have the schematic in front of me, but I'm not smart enough to post it. That is Frank's specialty. Perhaps he will be good enough to do that. If you have access to Riders, it is in Riders 23, Silvertone page 36.

Your signal generator should be warmed up enough to stabilize.

I suggested you start with the second IF transformer to help eliminate confusion. Put the hot lead of your signal generator, in series with your .01 uf isolation cap on Pin 1, the grid, of the 12BA6. Set your signal generator for a modulated tone at 455khz, the IF of your radio. Put the ground of the signal generator on one terminal of the power switch, B-, in series with another .01uf isolation cap. Connect your analog meter, set on the lowest AC scale, across the voice coil of the speaker. Select the correct tool to be able to turn the slugs on the IF transformers. Check all four adjusters. They have been known to be different.

Turn the radio on and let it warm up for a bit. Set the dial to wherever the alignment instructions say to, usually at a quiet spot at the upper end of the dial. You will want the volume control turned on full. You want just enough signal from your generator to be able to barely hear the tone. Watch the meter, and do not allow the signal to rise over a volt or so as you peak the transformers. Turn the generator output down each time it rises over a volt or so. This is very important to keep the AVC from messing up your work. Start with the bottom slug and turn it first one way, not over a turn or so, then the other until you hear the tone from the generator. Go easy, like I said. Just a bit at a time. When you have peaked the lower slug, do likewise to the top slug. When you feel the top is peaked, touch up the lower one again, then the top one, until you are satisfied that it is the best you can do. Being a touch off will not cause any harm.

Another tidbit that may help you. Sometimes, it works best to turn the signal generator up pretty good until you hear the tone. Then turn it down until you can barely hear it, and proceed with the alignment. Sometimes, you won't hear anything at first, until you start turning the trimmers. There may be some fumbling with this, but don't worry about it. Just get that tone, then adjust the generator input accordingly. When you hear the tone, run the tuning cap from one end to the other. You should hear that tone pretty much everywhere on the dial. If it comes and goes at regular intervals, you may have tuned to a harmonic of the IF and will need to start over.

Then turn off the radio, and connect the hot lead of the signal generator to the grid of the 12BE6, pin 1. Turn the set back on and do the same with this transformer as you did the other. The bottom slug first, the top next. Adjust each slug a couple times. After you get this transformer as good as you can, leave all your connections alone, leave the generator connected like it is, and try adjusting the second IF again. See if it is as good as you can get it. Then go back to the first IF and do it again. After you are satisfied that this one is okay, you are done with the IF alignment. I would expect the radio to play at this point. It might tune broadly or have one station more than one place on the dial. All we want at this point is for it to play. We will touch it up as the next step. Good luck.

WC


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Re: Help!!!

Post by frank1956 on Fri Sep 05, 2014 8:45 pm

Wildcat445 wrote:Frank, try this.  Determine what type of adjusters you have.  Commonly they will either be slotted or hexagon shaped.  

With the radio off and unplugged, and using your pocket screwdriver, make sure the alignment slugs will turn.  Sometimes they get stuck over time.  Plastic tools may not want to turn them.  So get them to move with a metal pocket screwdriver.  Do this like adjusting a carburetor, just a fraction of a turn at a time.  Like a quarter turn.  Fairly gingerly at first until you get it to move.  If your set has hex shaped adjusters, get an Allen wrench and turn them.  Freeing them up first will make adjustment easier.

Jerry, I have the schematic in front of me, but I'm not smart enough to post it.  That is Frank's specialty.  Perhaps he will be good enough to do that.  If you have access to Riders, it is in Riders 23, Silvertone page 36.

Your signal generator should be warmed up enough to stabilize.

I suggested you start with the second IF transformer to help eliminate confusion.  Put the hot lead of your signal generator, in series with your .01 uf isolation cap on Pin 1, the grid, of the 12BA6.  Set your signal generator for a modulated tone at 455khz, the IF of your radio.  Put the ground of the signal generator on one terminal of the power switch, B-, in series with another .01uf isolation cap.  Connect your analog meter, set on the lowest AC scale, across the voice coil of the speaker.  Select the correct tool to be able to turn the slugs on the IF transformers.  Check all four adjusters.  They have been known to be different.

Turn the radio on and let it warm up for a bit.  Set the dial to wherever the alignment instructions say to, usually at a quiet spot at the upper end of the dial.  You will want the volume control turned on full.  You want just enough signal from your generator to be able to barely hear the tone.  Watch the meter, and do not allow the signal to rise over a volt or so as you peak the transformers.  Turn the generator output down each time it rises over a volt or so.  This is very important to keep the AVC from messing up your work. Start with the bottom slug and turn it first one way, not over a turn or so, then the other until you hear the tone from the generator.  Go easy, like I said.  Just a bit at a time.  When you have peaked the lower slug, do likewise to the top slug.  When you feel the top is peaked, touch up the lower one again, then the top one, until you are satisfied that it is the best you can do.  Being a touch off will not cause any harm.  

Another tidbit that may help you.  Sometimes, it works best to turn the signal generator up pretty good until you hear the tone.  Then turn it down until you can barely hear it, and proceed with the alignment.  Sometimes, you won't hear anything at first, until you start turning the trimmers.  There may be some fumbling with this, but don't worry about it.  Just get that tone, then adjust the generator input accordingly.  When you hear the tone, run the tuning cap from one end to the other.  You should hear that tone pretty much everywhere on the dial.  If it comes and goes at regular intervals, you may have tuned to a harmonic of the IF and will need to start over.

Then turn off the radio, and connect the hot lead of the signal generator to the grid of the 12BE6, pin 1.  Turn the set back on and do the same with this transformer as you did the other.  The bottom slug first, the top next.  Adjust each slug a couple times.  After you get this transformer as good as you can, leave all your connections alone, leave the generator connected like it is, and try adjusting the second IF again.  See if it is as good as you can get it.  Then go back to the first IF and do it again.  After you are satisfied that this one is okay, you are done with the IF alignment.  I would expect the radio to play at this point.  It might tune broadly or have one station  more than one place on the dial.  All we want at this point is for it to play.  We will touch it up as the next step.  Good luck.

WC    



WC, I have tried the pocket screwdriver on the IF Can and it will not turn, nothing to bit on. It might be a hex screw I will have to find one to fit it if it is. There was noting like that in the alignment kit I got yesterday. I have looked at it under a magnifying glass and to me looks like the screw head is worn down, but let me find the hex screwdriver and see if that works.
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Re: Help!!!

Post by 75X11 on Fri Sep 05, 2014 9:10 pm

Inspect it well, they might have put some sort of sealant on it to prevent it's movement. On most of them the cores are brittle ferrite and can break if forced. Usually wax is used to inhibit the slugs' movement. If you see something like paint or varnish stop and advise.
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Re: Help!!!

Post by frank1956 on Fri Sep 05, 2014 11:21 pm

I have inspected it pretty good, did not notice wax or anything like that. But the 2nd IF transformer both top and bottom turn with no probably as does the bottom of the 1st IF transformer. All with a flat tip alignment tool/pocket screwdriver.
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Re: Help!!!

Post by Guest on Fri Sep 05, 2014 11:37 pm

Frank, I know it's last minute but I'll be at the Ruckersville Rummage this week-end, Sat & Sun. I can bring a variac if you want. It's where US 29 and US 33 cross each other.

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Re: Help!!!

Post by frank1956 on Sat Sep 06, 2014 9:25 am

MEZLAW,
Thanks. But I will be tied up with something else this weekend. If you are going to be over that way one day during the week I could meet you as I am free just about any day during the week. Weekends sometimes

Frank
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Re: Help!!!

Post by Wildcat445 on Sat Sep 06, 2014 5:38 pm

Frank, have you figured out what it will take to turn the trimmer that is stuck?

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Re: Help!!!

Post by frank1956 on Sun Sep 07, 2014 10:06 am

WC, No it not moving. Mad  Figured out it is not hex, but rather for a flat tip. Looks and feel's like the head has been stripped were nothing can get a grip on it. Tried several pocket screwdriver and nothing. What is next step replace the IF transformer/remove and inspected please advise.

Thanks
Frank
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Re: Help!!!

Post by Wildcat445 on Sun Sep 07, 2014 11:26 am

Frank, why don't you just go ahead with your alignment, using three trimmers that will move. Do the second IF first, then the first IF. See if we can get the alignment close enough that the set will play. It may not have to be in perfect alignment to work okay. If we can't get the alignment close enough, then, yes, you will have to replace the IF transformer unless someone has an idea on how to free that trimmer. I have, in the past, removed the can from the transformer and cut a new slot in the trimmer. That activity is rife with possibility for failure, but may be an option since you would have to replace the transformer anyway. Good luck.

WC

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Re: Help!!!

Post by 75X11 on Sun Sep 07, 2014 8:50 pm

This is the only illustration and description of this tool I know of. It says it can be used to change the induction of an IF xfmr without moving the slug so as to see if it would have any influence. One could probably be fabricated using a small tuning slug and a plastic rod.

http://www.antiqueradios.com/forums/viewtopic.php?f=19&t=233370
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Re: Help!!!

Post by frank1956 on Mon Sep 08, 2014 1:35 pm

All,
Thanks for the help, but don't seem to be able to get this radio to corporate. Does not want to align properly and same problem I was having prior to the alignment procedure. Went it wants to pick up a signal it does and when it don't it will not, which in turn get very frustrated. So I believe I will have to put this on hold for the time being and come back to it some other point in time. Just before making this post I went back and tried the alignment again with zero results. I am not a quitter, but there is a time when enough is enough, as you can see we are up to number 20 on this thread along. The radio is in better shape now then when I got it, re-wired, re-caped and new resistors.

Alignment did not produce the results that it was suppose to. Instruction were followed and re-followed. This is way it has been awhile since I have posted any results, wanted to make sure the proper procedure were being followed. No tone was produced nor was there any voltage reading produced on the analog meter across the voice coil on the speaker and I watched it very carefully.  

Again thanks to all for their help and for sharing their knowledge. I can truefuly say I have a better understanding and a respect for this hobby. It will not be my last project rest assure. I am have another project in the works, but hopefully will not be as difficult as this one. Laughing

Frank
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Re: Help!!!

Post by Bill Cahill on Mon Sep 08, 2014 1:48 pm

The voltage is too low there to measure it. It's about a tenth of a volt.
That's a bad place to try to measure voltages.

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Re: Help!!!

Post by 75X11 on Mon Sep 08, 2014 4:07 pm

Sometimes an easier project can teach you to get around the more difficult problems..
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Re: Help!!!

Post by 35Z5 on Mon Sep 08, 2014 5:00 pm

frank1956 wrote:All,
Thanks for the help, but don't seem to be able to get this radio to corporate. Does not want to align properly and same problem I was having prior to the alignment procedure. Went it wants to pick up a signal it does and when it don't it will not, which in turn get very frustrated.

Frank

Which means it has some problem alignment isn't going to fix... Alignment is performed so receiver will be at it's best performance, isn't going to fix a intermittent problem...  

Looking back with hindsight 20-20 & all, we should have nuked that thing for 4th of July... Laughing

Though with all the repair, I'm going to guess it has a intermittent IF transformer, they don't always make noise when bad...
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Re: Help!!!

Post by Bill Cahill on Mon Sep 08, 2014 5:29 pm

Could be I F is opening. He's right. Sounds like something intermittent.

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Re: Help!!!

Post by frank1956 on Tue Sep 09, 2014 10:11 am

35Z5 wrote:
frank1956 wrote:All,
Thanks for the help, but don't seem to be able to get this radio to corporate. Does not want to align properly and same problem I was having prior to the alignment procedure. Went it wants to pick up a signal it does and when it don't it will not, which in turn get very frustrated.

Frank

Which means it has some problem alignment isn't going to fix... Alignment is performed so receiver will be at it's best performance, isn't going to fix a intermittent problem...  

Looking back with hindsight 20-20 & all, we should have nuked that thing for 4th of July...  Laughing

Though with all the repair, I'm going to guess it has a intermittent IF transformer, they don't always make noise when bad...


Yea might not have been a bad idea. Oh well at least I have gain knowledge and much of great people.
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Re: Help!!!

Post by frank1956 on Wed Sep 10, 2014 5:13 pm

I would still like to get this Silvertone fixed. So what am I looking at ??? (Replacing the IF transformer) We have put alot into this radio like 3 months.
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Re: Help!!!

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