Author |
Message |
NelsonM
|
Post subject: Sears Silvertone Medalist All Channel Posted: Dec Mon 14, 2015 9:21 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
Hi there,
I recently saw an old Silvertone Medalist in need of a home on Craigslist and in the moment I had the bright idea that antique TV restoration would be a fun hobby that I can get into because surely the internet would have all the answers. In short, I need the help of you knowledgeable folks to bring this baby back to life. I have absolutely no experience in these sorts of restorations and minimal knowledge about electronics, but I can handle a soldering iron and I'm ready to learn so long as I won't be eligible for an electrical engineering degree at the end of the course. Is there any good literature that would get me up to speed? Maybe a thread or two in recent memory in which a lot of the basic info is consolidated? The local library here has a copy of Sams' ABCs of Television Servicing from 1962 and Sams' Photofact Course from the 70s in the archives... is anyone familiar with these?
I've been busy soaking up whatever I could in the short time I've had this thing. I realize that I'll need a schematic before I even attempt to start and not to plug it in and give it a whirl after decades in storage no matter how strong the urge. Luckily, the model sticker was still inside. It's a 19" Warwick set, 528.61497, circa 1967. There's absolutely nothing about this set online. If anyone is a collector of old Sears catalogs or has Sams Photofact folder 757-3, I'd very much appreciate any info that you can provide.
Between learning about toxic capacitor death fumes and high voltage heart explosions in the process, I figure it would also be prudent to ask about some of the common safety precautions that a new guy should take to avoid death and other death-like outcomes. What type of equipment should I have to do this job properly aside from an iron, multimeter, and an insulated screwdriver with a wire and a set of alligator clips? Is a HV test probe necessary? Variac (would the cheapo $50 2 amp ones on eBay suffice)? CRT tester? I see so many options for vintage CRT testers with a different sets of features... can anyone offer any recommendations?
Pictures to come as soon as the spam restriction is lifted.
Any advice, wisdom, and comments will be greatly appreciated.
|
|
Top |
|
 |
zeno
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Mon 14, 2015 4:18 pm |
|
Joined: Apr Sat 06, 2013 2:18 pm Posts: 421 Location: New Hampshire
|
Get the best equipment you can afford. For a variac look into the Sencore PR57. Its also an isolation transformer. After a meter its the next most useful thing. http://www.ebay.com/itm/Sencore-AC-Powe ... SwnipWZvMWWith that & a meter you can fix almost any B&W or color tube type TV. When you start on it DO NOT recap it. Fix it until you get some kind of pix on it to be sure the CRT, HV transformer etc are good. Then you can do the caps a few at a time, NOT all at once. The Sams books will be a good start to learn. Good luck & keep us posted. 73 Zeno 
|
|
Top |
|
 |
Findm-Keepm
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Mon 14, 2015 4:42 pm |
|
Joined: Sep Tue 30, 2014 6:08 am Posts: 3655 Location: The Old Dominion VA 23518
|
I've got the Sams if you need it - PM me if you wish to purchase it - say 6 bucks, shipped? The sams includes folder 3A, for the remote chassis, should your set be equipped.
One caveat to Zeno's comments - the input filter, a 150uF, 175V capacitor in a can, is likely bad, or will fail soon. I'd replace it before too long....
Cheers,
_________________ Brian "Capacitor Cosmetologist since 1979" USN Retired 1984-2006 (Avionics/Cal)
|
|
Top |
|
 |
Eric H
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Mon 14, 2015 11:14 pm |
|
Member |
 |
Joined: Jan Thu 01, 1970 1:00 am Posts: 10282 Location: Redlands CA
|
Caps were greatly improved by 1967, the set may work as found, or need minimal repairs, it depends a lot on how it was stored.
If you don't want to invest in a Variac right away you can power it up through a 200 watt light incandescent light bulb hooked in series with the AC line, it will be bright at first then taper down to barely glowing if there are no shorts.
|
|
Top |
|
 |
Mr. Detrola
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Tue 15, 2015 6:31 am |
|
Joined: Jan Thu 01, 1970 1:00 am Posts: 27234 Location: Detroit, MI USA
|
I agree, there's a good chance it doesn't have a lot wrong with it and it may even work. I would definitely try it out at reduced voltage before doing anything else, you should at least be able to get a good idea exactly what you have to start with.
_________________ Dennis
Experience is what you gain when the results aren't what you were expecting.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Tue 15, 2015 9:43 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
Thanks all for the replies. I got the TV for free which takes some pressure off of the budget, but the Sencore would put me over. I will definitely keep the brand and model in mind though if I catch the bug and this turns into a permanent hobby. Findm-Keepm, expect a PM soon. Off to the hardware store for that 200 watt light bulb! In the meantime, here's some for the eyes as promised. More here in this album for those interested: https://www.flickr.com/photos/nycnelson/albums/72157661716025530  
|
|
Top |
|
 |
zeno
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Tue 15, 2015 3:15 pm |
|
Joined: Apr Sat 06, 2013 2:18 pm Posts: 421 Location: New Hampshire
|
And its a remote set ! Never seen a Sears B&W remote. 73 Zeno 
|
|
Top |
|
 |
Mr. Detrola
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Tue 15, 2015 4:05 pm |
|
Joined: Jan Thu 01, 1970 1:00 am Posts: 27234 Location: Detroit, MI USA
|
There weren't a lot of B&W sets with remote control at that late date, I recall a few of them coming in the shop. It's also very unusual for a B&W set to have a wood table top cabinet in 1967.
That chassis and some variations of it was built for a number of years, including in some consoles. It's OK, nothing fantastic. They eat yokes and electrolytic caps, and the non-remote sets had far too many failures of the on-off switch.
You'll probably have to replace some electrolytics in the remote control receiver in addition to servicing the main chassis.
_________________ Dennis
Experience is what you gain when the results aren't what you were expecting.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Tue 15, 2015 6:11 pm |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
That's interesting and a little worrying at the same time. The previous owner said he'd let me know if he ever finds it, but the remote is officially MIA. I guess I should just disconnect the Molex to the remote control unit to spare the components while I focus on the TV?
Is there anything I can do to minimize the possibility of yoke failure or is it just one of those things that happen as a matter of course? The exposed coils are pretty crusty but intact.
|
|
Top |
|
 |
Eric H
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Tue 15, 2015 8:10 pm |
|
Member |
 |
Joined: Jan Thu 01, 1970 1:00 am Posts: 10282 Location: Redlands CA
|
The yoke will either fail or it won't, not much you can do about it other than brushing the dust off it.
I believe they mostly failed because the glue used on them corroded the wires, it depends on the glue used.
|
|
Top |
|
 |
Mr. Detrola
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Wed 16, 2015 2:10 am |
|
Joined: Jan Thu 01, 1970 1:00 am Posts: 27234 Location: Detroit, MI USA
|
This TV may not work with the remote chassis unplugged, you'll need to look at the schematic and see if any jumpers are required.
_________________ Dennis
Experience is what you gain when the results aren't what you were expecting.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Sun 20, 2015 4:57 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
Hi everybody, Chugging along slowly with this TV. Received the Photofact (thanks again Brian!) and started working on some of the cosmetics. Trying to decide whether to keep the patina that's developed on the wood. There's quite a bit of "crazing" on the finish for lack of a better woodworking term. Polished it down a little with some Novus #2 and finished it off with some Meguiar's Ultimate Paste Wax. Looks more half good than it does half bad so I'm leaning towards keeping it original. Which leads me to the first bad news. While disconnecting the HV anode lead from the picture tube in preparation for chassis removal, the rubber cup, rock hardened with age, crumbled over the screw driver. Unavoidable, but super bummed about it. Would it be advisable to tape the pieces back with some electrical tape or to leave it as is? The port on the CRT also looks a bit rusty. Would it be safe to juice this thing up? Crunchy cup: Attachment:
File comment: Crunchy cup
DSC_0370.jpg [ 174.4 KiB | Viewed 4772 times ]
Crusty hole: Attachment:
File comment: Crusty hole
DSC_0368.jpg [ 190.17 KiB | Viewed 4772 times ]
Crispy wires: Attachment:
File comment: Crispy wires
DSC_0369.jpg [ 178.04 KiB | Viewed 4772 times ]
Well, the chassis is out and once everything is cleaned off I'll check as many resistors and capacitors as I can before I put the finishing touches on the dim bulb tester and give it a go.
|
|
Top |
|
 |
ChrisW6ATV
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Sun 20, 2015 5:34 am |
|
Member |
 |
Joined: Dec Thu 06, 2007 11:54 pm Posts: 2888 Location: Hayward, California USA
|
I would replace the anode cap/connector with another one, maybe from a junk TV set if you can find one. Also, I would try to gently sand some of that rust off the anode connection on the CRT, but it will probably work OK without doing so.
_________________ Quote: (Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Sun 20, 2015 7:53 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
Are anode connectors universal?
If so, that won't be so hard. As it happens, I came across a big TV dump today.
|
|
Top |
|
 |
ChrisW6ATV
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Sun 20, 2015 8:38 am |
|
Member |
 |
Joined: Dec Thu 06, 2007 11:54 pm Posts: 2888 Location: Hayward, California USA
|
Most of them are pretty similar, yes. Color TV sets may use bigger ones or have thicker wire (for the higher voltages), but the clips should be close enough. Sony color TV sets often have a different type of connector though, so skip those ones as a replacement for other brands.
_________________ Quote: (Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Dec Sun 20, 2015 8:44 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
ChrisW6ATV wrote: Most of them are pretty similar, yes. Color TV sets may use bigger ones or have thicker wire (for the higher voltages), but the clips should be close enough. Sony color TV sets often have a different type of connector though, so skip those ones as a replacement for other brands. Thanks. I'll be on the lookout. Forgot this one: Attachment:
DSC_0363.jpg [ 216.77 KiB | Viewed 4752 times ]
Right side is after 2 applications of synthetic car wax. Left side was just cleaned off. Might buy a tub of Briwax once I know this thing will work.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Jan Fri 15, 2016 6:52 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
Hi again,
So I've cobbled together a bulb tester and managed to snip an anode cable from a 1997 20" Samsung. The old one had many more strands vs. the new one which only has 7 and is about 3 times longer. I'm hoping that won't be an issue.
But now a new hitch: in the process of desoldering the old lead from the tube socket pin, I ever so slightly melted the base of the plastic (although I'm convinced it's only a cosmetic disfigurement) and pretty surely cooked the little resistor there in the picture.
The markings and schematics call for a 4.7K Ohm resistor. Testing of the old resistor in circuit with the tube removed brings up 5.3K Ohms. After looking around, it seems resistors have more parameters that were left unspecified. Would a 4.7K Ohm 2% 2W metal film resistor be a suitable replacement? Am I correct to understand that, without measuring or having the info, the only way to determine wattage is by measuring the length (my little guy is about 12mm)?
Furthermore, I'm a little concerned about the plastic socket and would like to keep the application of heat to a minimum. Would it be proper to snip the old resistor on one end and push it aside then solder in the new one over it (there's not enough clearance to snip the whole thing out)? The thing is glued in there with a big glob of solder in close proximity to another wire and I can already tell it's going to take a lot of heat to get break it loose.
Many thanks.
|
|
Top |
|
 |
Eric H
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Jan Fri 15, 2016 7:38 am |
|
Member |
 |
Joined: Jan Thu 01, 1970 1:00 am Posts: 10282 Location: Redlands CA
|
5.3 k is close enough that I wouldn't worry about it, that's just a bit more than 10% off, probably well within the tolerance limit.
As for the new anode lead you can just cut it to the length you need, the number of strands makes no difference, the Samsung Anode can no doubt handle much higher voltage than the original.
|
|
Top |
|
 |
NelsonM
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Jan Fri 15, 2016 9:22 am |
|
Joined: Dec Mon 14, 2015 7:54 am Posts: 25 Location: New York City
|
Eric H wrote: 5.3 k is close enough that I wouldn't worry about it, that's just a bit more than 10% off, probably well within the tolerance limit.
As for the new anode lead you can just cut it to the length you need, the number of strands makes no difference, the Samsung Anode can no doubt handle much higher voltage than the original. Blah. Spent hours reading about and finding local sources for resistors, but of course I skipped the 3 second search that would have told me 3 band resistors have 20% tolerance... Thanks for saving me a trip to the store.
|
|
Top |
|
 |
zeno
|
Post subject: Re: Sears Silvertone Medalist All Channel Posted: Jan Fri 15, 2016 3:52 pm |
|
Joined: Apr Sat 06, 2013 2:18 pm Posts: 421 Location: New Hampshire
|
Yup the 4.7K is 20% so OK. Socket melting a little no issue. Often happens. Clean anode area with 91% isopropyl alcohol, do not scratch glass cleaning rust. When doing HV work do your best not to have sharp edges or they will ark. Ball soldering is best if you can get the hang of it, I never did. Practice first on something else. A longer anode lead may make it possible to run the set with chassis pulled out more. 73 Zeno 
|
|
Top |
|
 |
Who is online |
Users browsing this forum: No registered users and 5 guests |
|
|