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Duncan's 1960 Magnavox

Picked up this beautiful 1960 Magnavox Console.

I've restored a few vintage tube radios in my past, but never a TV before!

Everything, and I mean EVERYTHING appears to be original and untouched.

A few tubes have been replaced with GE units, and the 5U4GB is labeled "Japan"

I'm still learning here on my end, so any helpful advice, corrections, or input is always welcome!

A quick power up shows a decent picture!

I'm re-capping this set because the C2 4 section capacitor did blow out (overheated, swelled up, and popped) - causing loss of picture. The whole process took 2 seconds, and I shut the set off while the cap popped.

Year: 1960
Model # 1MV354 R
Chassis: V30-15-00

Dude that thing is a real time capsule, all I can say is WOW! Very nice catch.

Quote:

Originally Posted by ARC Tech-109 (Post 3258621)

Dude that thing is a real time capsule, all I can say is WOW! Very nice catch.

Thank you! I will take good care of it.

I started with replacing all the wax/paper capacitors & large 4 section capacitor in the audio amp.

I used slightly higher rated film caps inside the chassis (factory is 400v, I used 630v)

As I understand film caps are not polarity senstive and can be installed in any direction.

Multi-section can cap was replaced with a unit from Hayseed.

Re-installed the amp and everything still worked great!

https://live.staticflickr.com/65535/...1b03a2dc_b.jpg PXL_20240722_210024262 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...8bcd7817_b.jpg PXL_20240722_210111542 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...b6d5ab72_b.jpg PXL_20240722_211318305 by Thomas Duncan, on Flickr

New film caps (yellow)
https://live.staticflickr.com/65535/...bc4ed5d2_b.jpg received_2499329160274717 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...0aa5dfb3_b.jpg PXL_20240726_223320695 by Thomas Duncan, on Flickr

Removing TV chassis

TV chassis re-cap

I removed each paper/wax cap and started replacing them with film caps.

Again, I heard and read the diagrams online, it seems these yellow film caps are not polarity sensitive?

Most of the caps were rated to 400v, the replacement caps I used were around 600-630v. Same uF factory rating with a tolerance +/- 10%

https://live.staticflickr.com/65535/...d21a4619_b.jpg PXL_20240730_204949224 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...99bab2a9_b.jpg PXL_20240801_010015986 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...d9cd3e81_b.jpg PXL_20240801_010041094 by Thomas Duncan, on Flickr

I know any normal electrolytic capacitors ARE polarity sensitive, and should never have the + terminal installed to chassis ground.

I don't understand why the diagram shows Cap #4 with + to ground.

I thought it was a typo, but the OG capacitor was installed in the same way.

So, I installed the replacement 2uF / 50v cap with the + terminal to chassis ground.

https://live.staticflickr.com/65535/...4218069f_b.jpg PXL_20240803_005803186~3 by Thomas Duncan, on Flickr

OG cap:

https://live.staticflickr.com/65535/...1b6bf9bb_b.jpg received_1052973953063467 by Thomas Duncan, on Flickr

New cap:

https://live.staticflickr.com/65535/...9a3cf871_b.jpg received_1249401692693103 by Thomas Duncan, on Flickr

.

Very Nice TV! My Parents has a set like that - but only a tv. I spent many many nights
in front of it as a kid.... Watched till the stations went off the air at 3AM.
I would like a parts store like that near me......

.

Only lytics and IIRC Tantalums are polarized.

Your flyback is probably fine if it makes the screen light up that well. Many flys would normally drip some wax or tar (depending on what they're made of) over the course of their service life....It's also not uncommon for some of the tar to chip or peel off with age....the flyback doesn't need replaced it just needs recoating with wax, tar, corona dope or sensor safe RTV (which one is a matter of personal preference).

The positive grounded lytic probably filters a negative voltage rail. All tube gear has positive rails, but some have negative rails too. Some sets connect the can lytic capacitor negatives to a floating negative rail separate from the chassis, and if you change that bad results tend to occur. Another thing that can be confusing when you see it for the first time is a voltage doubler circuit.

Don't replace paper caps with ceramics in TVs, ceramics aren't stable enough for video and sweep applications that originally called for paper.

Quote:

Originally Posted by Electronic M (Post 3258646)

Only lytics and IIRC Tantalums are polarized.

.the flyback doesn't need replaced it just needs recoating with wax, tar, corona dope or sensor safe RTV (which one is a matter of personal preference).

The positive grounded lytic probably filters a negative voltage rail.

Don't replace paper caps with ceramics in TVs, ceramics aren't stable enough for video and sweep applications that originally called for paper.

Thank you for the info, I'll keep that in mind. I didn't know that about ceramics.

I'll pickup some blue sensor safe RTV from the store this weekend.

Out of the TV Chassis capacitors I replaced so far:
13 replaced with Film caps
1 with a Lyitic
2 with Mica (Hard to find value & tolerance) - Mica seems to be okay? - From what I can find online its not considered a ceramic.
.0039 uF @ 200v +/- 10% (Part of the Horizontal Hold Circuit)
.0051 uF @ 400v +/- 5% (Sits between the Sync Phase inv & AGC Clamper)

Micas are fine...expensive, but fine. Those 2 caps you changed should also be available as film capacitors (I don't think I've seen 5100pF used anywhere before and haven't looked for new parts that value) and I probably would have used Panasonic or Illinois Capacitor brand red film caps in those locations for budget reasons.

After reading multiple forum posts about re-coating the flyback, i've settled on the following RTV.

Brand name: Momentive / SNAPSIL

Model RTV: RTV-133 Silicone Rubber

It's been reported good to use on flyback transformers, and carries the following traits:

It does not produce acetic Acid .
It utilizes an atomospheric moisture cure system, which releases an
alcohol vapor from the sealant surface during cure.
Dielectric Strength: 20kv per 1mm layer.

I've got a MSDS sheet listed here for more reading/ spec.

The new can caps arrived from hayseed.

I installed one, and have one left to replace.

That just about does it for all the capacitor replacements.

The old can cap that was replaced was VERY leaky and way out of spec. It was reading 80-100% higher uF ratings than listed on the can.

https://live.staticflickr.com/65535/...61c87b09_b.jpg PXL_20240806_020045066 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...1f7f3f94_b.jpg PXL_20240806_020145917 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...ece988f2_b.jpg PXL_20240806_025948971 by Thomas Duncan, on Flickr

https://live.staticflickr.com/65535/...4523f9f9_b.jpg PXL_20240806_030359626 by Thomas Duncan, on Flickr