need help with Zenith k518

Go down

need help with Zenith k518

Post by snowscad on Mon Jan 29, 2018 12:41 am

I just purchased this Zenith K518 and I was told it had a hum in it so I replace all wax capacitors and
Electrolytics and when I went to plug it in and turn it on all tubes lit up and then they went out,nothing now so I check all tubes they check good on my tester and it seems they have the correct voltage if I'm not missing something and they are not lighting up.
And this radio has a clock on it, and it's not working and this is the first one I have every work on with a clock lm thinking it has something to do with it.also I have the schematics for it to.
All help is appreciated thanks in advance.
Dwain

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Mon Jan 29, 2018 10:14 am

I am going to do a lot of guessing here on this one. I don't have the sams in front of me. But from the picture I see online this is probably a late 50s maybe. I am thinking it has the smaller tubes maybe 35w4,50c5,12ba6,etc. With that said if it is or maybe larger ones I am guessing it doesn't have a transformer. The way the ones I have worked on the clock has a switch on it. This turns it on and off. Follow your wires from the plug to the chassis. There should be two wires going to it, one that is connected to the plug and one that is connected to the switch. See if where the wires go in to the chassis has 120.

You can also do this but have it unplugged. Normally these have tubes connected in series so make sure it is unplugged with power off and check the ohms of the wires going in to the chassis. Then if there is no reading in ohms follow the path to see where it is not connected. If it is one of the pc board type radios you may have a broke trace on the board or a connection that has a broke or bad solder joint. Look especially at the areas on the tubes the filliment is on.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Mon Jan 29, 2018 9:04 pm




Zenith K-518 1952
tubes
35W4
12BE6
12BA6
12AT7
50C5

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by CrystalRadioMan on Tue Jan 30, 2018 9:54 am

If you have been in there unsoldering capacitors, you may have damaged a terminal on one of the tube sockets.  This would explain why all tubes test good but do not light.  Check the voltage between pin 4 and 3 of every tube.  The tube with the broken terminal will have 120VAC across them.  I had this happen to an Arvin radio and the socket had a terminal break between where the tube pin plugs in and the solder lug portion.

But.........do what Wille says FIRST!  Very Happy
avatar
CrystalRadioMan
New Member
New Member

Number of posts : 8
Registration date : 2017-02-08

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Fri Feb 02, 2018 6:50 pm

Well I got the radio working after closer look at the 35w4 in my tester the filament between Pin 6 and 3 was out even though it let up in my tester I was thinking it was good so I put a new one in it that I had on hand and it worked I picked up the local stations real well but as I'm tuning through the dial I get a lot of Whistlin and Turpin and the clock is not working are they hard to work on does anyone know how to work on.
Thanks
Dwain

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Fri Feb 02, 2018 8:50 pm

If the clock is not working try these things. Check the coil. Chances are its a telechron clock motor. It will have a coil with two wires out. It should have a resistance reading. The issue I bet is the gear assembly with it. The gear assembly will look something like this.

http://thumbs1.ebaystatic.com/d/l225/m/ma9Kuj3CbjEtwhFUIni8MWA.jpg

On the bottom it will have a round bum out that fits in the coil frame. What I usually do is take a soldering gun and heat the shell. I have some light weight oil I put on the top and let it seep in. What happens is the grease in the assembly gets old and hardens. The heat loosens the oil and the lightweight adds oil lost over the years.

Here is a link to a description that explains it better than I do. As far as the whistlin and Turpin if its not WJLE it might be the silver mica disease as they call it. You can do a search on youtube for it and compare it to the sounds you hear on yours. As far as WJLE I am the fellow who live not far from you.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Fri Feb 02, 2018 10:36 pm

Thanks Willy I will look in to it and see what I can come up with
Dwain

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Sat Feb 03, 2018 10:59 pm

It didn't have SMD it was just some interference the radio sounds good now but i don't know about this radio it looks a little overwhelming to me I guess because I don't know anything about it but this is what it looks like.


snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Sun Feb 04, 2018 4:00 pm

snowscad wrote:It didn't have SMD it was just some interference the radio sounds good now but i don't know about this clock it looks a little overwhelming to me I guess because I don't know anything about it but this is what it looks like.


snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Mon Feb 05, 2018 8:00 am

That's a Telechron clock motor. One way to test it is to put a screwdriver close to the metal frame by the motor. But don't touch the wires. If I am not mistaken you should feel it attract the screwdriver the way a magnet does. The other way to test it is to have it unplugged and check the resistance of the two connectors coming out of the coil. If it tests fine and you get voltage to these two connectors when it is on then its probably the motor. Just use the link I posted and try to get the grease in the motor to loosen.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Mon Feb 05, 2018 2:24 pm

No magnet feel on frame with screwdriver and no resistance on coil connectors with it unplugged,plugged in I get 125v.
Does this mean the Coil is open?

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Tue Feb 06, 2018 9:33 am

snowscad wrote:No magnet feel on frame with screwdriver and no resistance on coil connectors with it unplugged,plugged in I get 125v.
Does this mean the Coil is open?


Sounds like its bad. I will have to check around to see if I have one. You can look at the spades where its soldered on. Look for a hair thin wire thats broke. Sometimes they break there. If you see it you can get a single strand of wire from a piece of stranded wire then wrap around the broke wire and then around the spade. Then heat it and let solder flow between the two.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Wed Feb 07, 2018 11:51 am

I took the clock out of case to get a closer look I think I know what your talking about when say spades but not sure and I don't see hair thin wire not if I'm over looking something in the last picture it looks like that one connector is bent would that be the problem and what do you use to clean it with.
I'm sorry but I don't understand all this radio terminology stuff.
Thanks for your time.





snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Wed Feb 07, 2018 1:43 pm

No problem , don't worry about the terminology it will come to you as you work on these. As far as the clock goes the spade I was talking about is the piece of metal the brown wire is soldered to. The piece coming out of the round object that has the metal frame going through it. I called it a spade as I couldn't think what else to call it, I heard someone call it that a long time ago.

Any way that piece the brown wire is soldered to is one end of the coil for the clock. The other spade is the other end of the wire coil. A coil is just a wire wrapped many times around a form of some type. As electricity goes through it a magnetic field is created. If one wire breaks then no field and the motor gears do not turn.

What you can do is to take a meter,put it on AC volts and see if there is 120 volts. If you get 120 volts across it when it is plugged up then you know its getting 120 volts. After that unplug it from the 120 wall socket. Then set your meter to ohms which is resistance to see if you get a resistance on these two spades, or pieces the wires are mounted to. I am thinking it should be 100 ohms or less but should have resistance.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Wed Feb 07, 2018 3:52 pm

willy3486 wrote:No problem , don't worry about the terminology it will come to you as you work on these. As far as the clock goes the spade I was talking about is the piece of metal the brown wire is soldered to. The piece coming out of the round object that has the metal frame going through it. I called it a spade as I couldn't think what else to call it, I heard someone call it that a long time ago.

Any way that piece the brown wire is soldered to is one end of the coil for the clock. The other spade is the other end of the wire coil. A coil is just a wire wrapped many times around a form of some type. As electricity goes through it a magnetic field is created. If one wire breaks then no field and the motor gears do not turn.

What you can do is to take a meter,put it on AC volts and see if there is 120 volts. If you get 120 volts across it when it is plugged up then you know its getting 120 volts. After that unplug it from the 120 wall socket. Then set your meter to ohms which is resistance to see if you get a resistance on these two spades, or pieces the wires are mounted to. I am thinking it should be 100 ohms or less but should have resistance.
plugged in I get 125v. no resistance across with it unplugged

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Thu Feb 08, 2018 9:23 am

From that it sound like the coil is bad. I will look around this weekend to see what I can find. I have some clock parts but I am not sure exactly. If your getting into these old radios don't miss the Meet in April at Nashville. Its on our side of Nashville and we don't have to go all the way in.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Thu Feb 15, 2018 7:30 pm

Hey Dwain, I have a question on this motor. when you look at this motor I need a measurement. On this picture

clock motor


When you look at it the bottom you see the side of the metal frame and across it you see a flathead screw that holds it to the clock frame and in the center you see the actual motor. On this motor can you tell me how wide from the side of the frame on the left to the right? In other words roughly from one frame side,across the motor to the other frame side. The one I have I think is about 1 and 3/4 inches across. They make others I think are maybe 2 inches across. I need to know the width. I may have others but I know I found the 1 3/4  wide one.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Fri Feb 16, 2018 2:19 pm




H-3 3.6 RPM Telechron motor hope this helps
Just let me know if you need something else.

Thanks,
Dwain

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Fri Feb 16, 2018 8:40 pm

You have what I think is the 2 inch wide one. I will keep looking. I am over the flu, my fever has been gone for over a day now so I am trying to get around more but still slow. I will see what I can find.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by snowscad on Sat Feb 17, 2018 10:03 am

Glad you're feeling better but don't over do it just for me if you not got one that's ok I may be able to find one online somewhere.
Thanks

snowscad
Member
Member

Number of posts : 18
Age : 62
Registration date : 2017-04-27

Back to top Go down

Re: need help with Zenith k518

Post by willy3486 on Sun Feb 18, 2018 12:35 am

No problem at all. My shop is a mess and hard to find stuff now. At one time I think the one you have is the one I needed and didn't have it but that was a few decades back. So this smaller one I rigged up to use. But I got one to replace it. I did see one on ebay I think exactly like you need. My daughter is visiting this weekend so maybe I can check tomorrow afternoon or Monday.

willy3486
Member
Member

Number of posts : 1420
Registration date : 2011-07-02

Back to top Go down

Re: need help with Zenith k518

Post by Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum