Admiral 19A11 tabletop
 

In the Admiral 19A11, what's the deal with these rear-panel potentiometers (like Focus) with the nylon shafts and innards? They're all really, really sticky. I took apart the Focus pot to see if it was frozen with gunk or melted. Looks like new. I cleaned it anyway, and applied a little electronic lubricant. It's still so stiff that it feels like I'm going to ruin the shaft when turning it.

http://antiqueradio.org/art/Admiral1...entiometer.jpg

Is there some magical lube that will make these turn normally?

On the positive side, it looks like there's some life in the CRT. All I've done so far is replace the power-supply electrolytics and the 6KV-rated caps.

http://antiqueradio.org/art/Admiral19A12FirstImage.jpg

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

If it's the shaft that's binding, it may have swelled over the years. I'd try some fine emery paper on it to reduce it a little followed by a good cleaning and relubing.

Looks like you've got a GOOD 7JP4 there...

Yes, it's the shaft that binds, and only in the enclosed part (the portion that hangs out beyond the chassis doesn't bind at all). I didn't know that nylon can swell. Sanding sounds worth a try.

Regards,

Phil Nelson

I have the same situation with the 17T1. Focus knob is very tight. Curiously, the adjacent horiz. cent. knob is less stiff and the vert. cent. knob doesn't bind at all. I think maybe that corner of chassis is hotter.

Same deal with the three nylon pots on my set. Tight, tighter, tightest. Swelling from heat would make sense.

Phil Nelson

I'd guess that the most probable suspect is the nylon, but another thought, might be the bearing has swollen.

Pot metal is well known to swell with age and I'd assume that these bearings probably were cast and not machined.

On some pot metal assembles from the 1920's, I've run into swelling pot metal that has pinched the steel shafts after long storage. I found it easier to ream the bearing than to polish the shaft and either seems to work equally well.

You know, my first thought was swelling of the Nylon. But reading "earlyfilm's" suggestion of swelled pot metal, that makes sense. And, it may be easy to ream it out with the appropriate sized drill.

Just a thought.

Does anyone happen to have a scan of the Sams manual (59-2) for this model? My library doesn't have the paper version and they cancelled their subscription that formerly let me download manuals for free.

I got the Riders manual from the ETF archive, but the more docs the better :)

You can send me email via http://antiqueradio.org/contact.htm .

Phil Nelson

I just emailed it to you. Enjoy.
- Winky

Thanks!!

Phil Nelson

The Admiral's looking better, after a basic recap and some new resistors.

http://antiqueradio.org/art/Admiral19A12ThirdImage.jpg

This set was somewhat recapped long ago, by the look of the replacement caps used. I found a couple of funky things and I wonder how well it worked at that stage, if at all. The picture tube was very crooked, as seen in the first photo. It's hard to imagine someone watching it very long in that condition.

Perhaps this is a later version. It has a vertical linearity control on the back panel that's not shown in either manual.

Phil Nelson

Vert Lin Control in 19A1 Models
 

My 17A1 has the vertical linearity control, and I have this schematic showing the control on two 19A1 models, the 19A11 and 19A15. I have no idea where the schematic came from. It looks identical to the Wallace schematic with a slightly different drawing style.

https://lh4.googleusercontent.com/-F...rt%2520lin.jpg

- Winky

Phil-

Some people have said that the 7JP4 TVs have mediocre pictures compared to bigger sets, but yours has as good a picture as I could imagine could be created on any 7-inch CRT. If any of my 7" sets look anywhere near that good when I restore them, I will be very happy. Nice job!

The picture quality on that set is fantastic. I wish my Tele-Tone looked that good. Inspiration to find a stronger 7JP4 for it for sure.
Keep up the good work :thmbsp:.