Blonde Port Started
 

Finished up the teletone and now off to the Blonde port hole set. Just a few pics of the disassembly of the unit and everything looks fine except the black waxy insulating material on the flyback is cracked on some of the pieces have fallen off. The unit rings out ok and wondering what I can use to either hold the remaining stuff on or replace it, any suggestions.

People here tend to coat the flybacks in RTV silicone, but any other material with a high resistivity/breakdown voltage should do the job.

You're probably best removing the loose stuff before you put anything new on it, to minimize the air space around it - and then really work the stuff on so it's there's as little air as possible around the coils.

That should prevent any arcing from happening as a result of the cracked outer tire.

It has been found that some of the silicones, and, other types tend to be corosive, and, reccommend against them.
Bill Cahill

I'm curious, could the unit be coated with corona dope?

get the sensor safe rtv at the auto parts store. acid free.

It looks like most of that wax will flick right off if you warm it with a heat gun. That's what I did recently when recoating a Philco flyback. I had meant to melt it off like liquid, but the stuff just started falling off in big pieces when it got warm.

This thread has some photos and a couple of recommendations for recoating material. I used sensor safe RTV. Eric H recommended some space age stuff from Aervoe.

Phil Nelson

Yours looks like my 24H20/24H21 that still works with only tubes and a couple of papers that were replaced in the 1970's. Does yours use a second audio/power chassis?

Tom C.

Tom,
It has the second chassis for the power audio. Portholes are nice sets and hoping to get her running in a couple of months as I have a mahogany unit coming at the end of the month.

Brandt

Well, re-coated the flyback with the sensor safe material. Looks like more of a bad cupcake frosting job but there are no voids on the inside. Currently recapping the chassis and going to replace the 6 sand power resistors as i have never had good luck with them working after such a long down time. The other mahogany porthole showed up yesterday and will post up some picks later on.

Was there a thread with pictures of the cabinet? I just picked up a blonde porthole combo myself.

Here's the link
http://videokarma.org/showthread.php?t=250578

Nice!

Finished with most of the paper caps and waiting for the new power resistors to come and I'll finish off the electrolytics.

This is a dumb question, but how did you get the CRT off? When working on my 12" porthole, I just lay the chassis on its size and clamp it to the bench (with the CRT attached). My 16" though, I am afraid that it might be too heavy or whatever. I haven't worked on that one yet. Can you take the CRT off without screwing up anything alignment-wise?

Well I'll see if I screwed up some alignment but after marking the tube in the yoke, I removed the high voltage springs, then the front support and insulator ring and supported the bottom of the tube with some foam. The tube (16gp4 metal tube) in my unit was very light compared to say a 12lp4 unit and it slid out ok but still was white knuckling it cause of the very long neck.

Just added all of the photos to the photo bucket site. Both this Fielding porthole which is being restored and a few of the unknown unit I picked up over Memorial Day

http://photobucket.com/portholes

Brandt

Boy, I wish I had that blonde one. It's a beauty.
Bill Cahill

Egad! what happened to that CRT? Looks like it was shipped by UP-- er, I pronounce it "OOPS" :D

When I removed the CRT from the chassis, a little bit of the dag peeled off. Seeing as it's a metal glass tube, I might leave it this way

ah, ok. Looked a bit like there was a massive dent in the side of it! :)

That's not dag, it's some sort of insulating paint. On new CRT instructions, they say to avoid touching it. That could be an early 16GP4, as the later ones they didn't seem to bother painting the glass any more. I'd just clean all that old shit off. Don't understand why they would think it necessary to insulate glass in the first place.

Thanks John, that's what I thought as the other unit I have does not have it at all, I clean it off when I re install the CRT for testing

Well, fired up the set on my variac and both the 360 and 130 volt system came up with no problem. Left the horizontal output tubes as well as the CRT out for the test. Connected the speaker and the VCR and got pretty good sound out of the speaker so most of the front end is running as well as the sound. Hopefully I'll get the CRT installed tomorrow and see if I can get a raster out of it. Gonna cut some insulator rubber sheet and cover some of the exposed CRT cone so I can minimize the chance of me having a new hair doo.

's only a couple thousand volts :D

An old tech acquaintance joked about it to me once.
The current from the CRT is quite low - 20kV hurts like hell, but what's more dangerous is gashing your hand open on something else sharp as it's involuntarily jerked back!

In all seriousness though, a healthy dose of respect for any high voltage device is good for your safety :)

Finally got a bit of time on the porthole and did a slow power up with the crt and got a raster at around 80 volts. Hooked up my vcr and did a little adjustment and got the picture up and running. The vertical size pot is bad as you adjust it up around mid range and the screen goes to a thin line and just past that the picture expands to super size. Rang out the pot and seems to have several dead spots so it's gonna be replaced. Overall the brightness adjustment is at about 1/3 up in the dark and the crt provides a real bright picture so guess i got lucky on this 16gp4. Now for the analyst and check for other problems.:banana:

oh the photobucket link

http://photobucket.com/portholes

Great progress on a great looking set! I sometimes wish here in NZ we had TV earlier than 1960...There would have been some cool looking sets around like this one! Cheers Glen

Did a bit more work on the set and couldn't get the noise out of the sound system. Also the picture was not entirely stable as I had to keep adjusting things to keep the picture good. Read a bit here and from the antique radio forum site and tried replacing the 6BN6 which cleared a bit but not much improvement. Decided to replace the tubes in the if section:yes: as the picture stability and the static from the speaker sort of coincided. After replacing the 2nd if stage 6AU6, everything stabilized and the hum disappeared with just a bit of adjustment on the buzz control. Put that tube back into the checker and it tested ok but after a minute or so, the short light on the checker dimly lit. Guess I'm gonna have to allow the checker to heat long before saying it's a good one. Right now just letting it run and so far so good after an hour

Went ahead and finished up the TV and installed into the cabinet after doing a bit of clean up and waxing on the cabinet. I was really lucky as the restore went very well and only had a few minor bugs. This set is really going to be a great addition to my old 1922 house and cant wait to have a viewing party with some of my friends. Here are a couple of pics

Man, that looks very promising! Keep plugging away, it will make a nice set!

Very nice one!