Duncan's 1960 Magnavox

[Mr.Duncan]

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.

PXL_20240806_020045066 by Thomas Duncan, on Flickr

PXL_20240806_020145917 by Thomas Duncan, on Flickr

PXL_20240806_025948971 by Thomas Duncan, on Flickr

PXL_20240806_030359626 by Thomas Duncan, on Flickr

[Mr.Duncan]

Today's the day!

Finished replacing the last multi sectional capacitor.

The old one was VERY swollen and leaking fluid.

I powered the set up slowly with a variac.

At full voltage I'm pulling 2.5 amps which seems to be normal. No abnormal sounds, no arcs.

The photo below kind of exaggerates how bright the tube filaments are glowing. Much more mellow in person.

I'm getting just a non-adjustable horizontal line across the screen.

So I'll need to do some reading as I have no clue what controls the vertical movement of this line?

**I only ran the set for about 30 seconds with the screen set to minimum brightness** - didn't want to burn the CRT.

PXL_20240806_221113960.PORTRAIT by Thomas Duncan, on Flickr

PXL_20240806_225509131 by Thomas Duncan, on Flickr

PXL_20240806_230959278 by Thomas Duncan, on Flickr

PXL_20240806_230953330 by Thomas Duncan, on Flickr

The safety glass in the display makes the line look much thicker than in person.

PXL_20240806_225528496 by Thomas Duncan, on Flickr

[Mr.Duncan]

Upon checking both these tubes, one BARELY shows good on my tube tester.

6BF6 - Pass
Vert OSC & AGC

6DT5 - Fail? - Readings are poor.
- Labeled as VERT output.

Photo of 6DT5 test below.

PXL_20240806_234132521 by Thomas Duncan, on Flickr

PXL_20240722_010820973 by Thomas Duncan, on Flickr

[Mr.Duncan]

I did end up re-coating the missing wax area of my flyback with silicone.

Everything worked great, I gave it 48+ hours to cure.

Silicone info is listed below.

Also picked up a spare NOS flyback to keep as a spare.

I think I need to re-cap the power supply to my Blonder Tongue, I'm getting a rolling bar on the screen. Rolls from bottom to the top. This occurs on both my CRT TV's.

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.

PXL_20240815_205641719 by Thomas Duncan, on Flickr

PXL_20240820_230248590 by Thomas Duncan, on Flickr

[Electronic M]

Originally Posted by Yamamaya42

They were one of the biggest BW tubes ever made, however, they don't last very long, cause they tend to push the gun rather hard, mine works, but is on the weaker side.

I got it all for free, as it was just a chassis and CRT from a set that someone made into a pet bed, It's a newer one than yours, but still uses a 24AHP4.
https://www.youtube.com/watch?v=PvMHr4-WO8s

Yup. Until this spring you would have had my then biggest direct view set (23" Setchell Carlson School TV) beat. I believe there were 25, 27 and 30" built too, but the 30" Dumont Royal Sovereign was the biggest monochrome direct view ever. The Dumont is stupidly rare and heavy and on top of that it's hard to find one with a good CRT let alone a spare....So in spring I jumped on a 27" Muntz that the ETF had with a strong CRT in it. I think I paid something like $5 (they'd been trying to sell it for over a year) and unlike the Dumont I can actually move the damn thing myself.
It isn't my biggest monochrome picture though....at 5' diagonal the picture my Norelco protelgram duo-vue projector can throw onto a screen is fairly impressive...as well as dim.

Originally Posted by Mr.Duncan

I think I need to re-cap the power supply to my Blonder Tongue, I'm getting a rolling bar on the screen. Rolls from bottom to the top. This occurs on both my CRT TV's.

Yeah, better than half my BTs have new caps...One of them had its bridge rectifier die during a lightning storm (which is weird because it and it's antenna are in the basement and there was a ton of other stuff plugged in and running that wasn't harmed).
Granted that hum bar isn't always caused by caps.... sometimes they're happier (read don't develop bars from hum loops) being ungrounded or even isolated from the grid...my main BT rack is powered by an isolation transformer and a PC in that rack is plugged in to an adapter that ungrounds the cord.

[Alex KL-1]

Originally Posted by Electronic M

.......................................



Yeah, better than half my BTs have new caps...One of them had its bridge rectifier die during a lightning storm (which is weird because it and it's antenna are in the basement and there was a ton of other stuff plugged in and running that wasn't harmed).
............................................

Sometimes I see these almost impossible to describe lightning discharge hitting only one device, sometimes one of the last of the chain... oh, these kV pulse propagations...