New Project - RCA 8PT
 

Today a package arrived, containing a very nice little TV, the RCA 8PT, black, with a swivel stand. It's in excellent physical condition, and my goal is to get it into excellent electrical condition as well.

Opened it up, cleaned out dust, tested the tubes... it needed only one tube, a 6U8, curiously the only non RCA 6U8, a Japanese Channel Master, was bad.

Turning on the TV it gets a nice bright raster, and good sound, but the horizontal hold can't be dialed in.

One symptom worries me a bit, probably due to ignorance. With the Horizontal frequency control at a low frequency (I can hear the flyback), the out of sync image is nice and bright. As I turn up the frequency, it hits a point where the image horizontally collapses into what looks like a modulated vertical stripe, and the screen gradually goes dark. I think I can hear zapping sounds in the flyback, or maybe the frequency is just all over the place, but whatever it is appears to be killing the high voltage. Turn down the horizontal frequency, and the image comes back, full brightness, and the high voltage appears to be restored, but sync is impossible.

I am going to replace all the capacitors in the TV before I worry too much about the lack of horizontal sync, but the possibility of a bad flyback is a bit worrying. I wonder what the experts think.

I have to say, it is a nice contrast to my other vintage tv, in that moving it around can be done with one hand!

Looks like we've got another spammer!

"china wholesale". Yeah,that's just what people on a *vintage* tv site want...Chinese crap!

Spammer banned.

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Neat little sets, although the innards are tightly packed. This article has a link to the RCA factory service manual, and a few notes that may be helpful.

http://antiqueradio.org/rca16.htm

Phil Nelson
http://antiqueradio.org/index.html

My best guess would be the .047/600v paper cap in the boost circuit...And yes, I have also heard odd clicking noises when the frequency is way off and "squigging" (if that is the proper term). There are only about 4 paper caps in the horiz section (2-.047s, 1-.022 and 1-.22), I think that I would do those first and re-check the performance,
jr

Thanks all for the input!

I think I better go against my desire to see a picture on the screen now, and wait for all the capacitors to show up before I continue on. I'm happy to know this doesn't mean the flyback is suspect, at this point. In addition to the symptom mentioned above, the B+ is about 160, and should be 216, so fresh electrolytics and ditching the selenium rectifiers sure looks like it won't hurt.

Phil - your website is great, I remember reading about your TV several years ago when I used to go on rec.antiques.radio+phono. That's where I first became aware of this model. I printed the service manual from your website about a week before the TV arrived, to have an idea what to expect. I have to say I am surprised by how small everything is... even the controls are tiny.

I cleaned up the case with a toothbrush and warm water... it looks nearly new, although maybe it could be a bit more shiny. The only defect is the antennas are broken.

finally got my order in at mouser - 39 caps and two diodes. If it takes half as long to install these as it did to order them online I'm doing well :)

It's amazing how much grime gets trapped under safety glass...

Yeah, well, you gotta remember that l'il guy is 51-54 yrs old, & I'd about guarantee SOMETIME in its life it was around a smoker or 2, a few pets, & prolly some kids...Too bad these things can't talk-I'd LOVE to hear some of the stories they could tell...

I have one of those I have been using regularly for ten years now. I did a full recap when I got it and it works great. These are some of the best built vintage portables around, transformer powered, no printed circuits, all metal cabinet, etc. Once restored, it will reward you with years of viewing pleasure and it is small enough to use and display anywhere. Take your time with it and it will be well worth it. Let's see some pictures along the way.

Photos 1 of 2
 

As requested - here's some photos. Set is basically as received from member Eric H, aside from some light dusting and cleaning. As you can see it is in excellent internal and external condition!

Photos 2 of 2
 

You can see where I damaged the vertical hold knob a little bit when I was putting the chassis back into the case. Luckily it just cracked off a piece, which I recovered, and it didn't crumble, so I can glue it back together. These knobs are very delicate! When you separate the front and rear halfs of the chassis, getting it lined up again so everything lines up is a bit critical. Mine is one of the later models with safety glass instead of plexiglass, so it is very easy to clean and free of scratches.

Those small knobs are often missing, probably more than half my 8" sets are missing them entirely.
Someone should repro them, shouldn't be too hard provided you can come up with a pristine one to make a mold from.

I have (had) 12 of these little guys, I think every single one of them would at least display a raster without anything being done to them, usually the Horizontal won't quite sync up, that's pretty amazing, only one has a bad CRT , way better odds than most sets.

That is about the condition mine was in when I first got it. Mine produced a weak picture with no sync when I got it. Since restoration it works like new and the CRT is strong and bright. It would have been nice if RCA had used an aluminized tube. I used to lament the lack of UHF on these sets but since the digital switch over it is no longer an issue. They make great daily watchers. It is a lot of work disassembling that cramped chassis and getting to all those paper caps but the results are well worth it. I am surprised RCA put so much into this set considering they were using PC boards in their much more expensive products.

Wow, a portablel with a transformer!