#46
|
|||
|
|||
"Now there's a surprise!" Glad you checked Bob. But, I was sure that you did.
|
#47
|
||||
|
||||
What was a little surprising is that all the larger valued resistors (10K and up) were within spec. It's the smaller (< 500 ohm) resistors that were way off. I've seen the same in some early Admiral sets.
|
#48
|
||||
|
||||
Quote:
No manufacturer was ever able to eliminate moisture as a problem. IRC tried, and got a patent for their "molded" carbon composition resistor process that sealed the outside of the resistor and thus reduced moisture intrusion, but aging and lead flex allowed the moisture intrusion. If it wasn't for economy and pulse/surge capability, carbon composition resistors would have been dead long ago, as most film types suck at handling surges. And no, you can't bake the moisture out - DoD and NASA both tried, but found that the heating process shifted resistance greater than the moisture did. Cheers,
__________________
Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! Last edited by Findm-Keepm; 11-18-2013 at 09:58 PM. Reason: added "on the shelf" |
#49
|
||||
|
||||
I recently purchased some carbon comps from Allied Electronics for those "special" sets where I'd like to retain the original look. Also, they were dirt cheap
Check out the bag they came in. Along with the 1/2w 100K resistors inside was this humidity strip and some silica gel desiccant. It seems to have helped. Every resistor is +/- 5% with a bunch being under 100K. I spot checked a few from my non-environmentally sealed stash and all are high but still just within tolerance. |
#50
|
||||
|
||||
Audiokarma |
#51
|
||||
|
||||
Before I forget, would you mind taking a quick shot of the tuner string when you get a moment? On the one I'm doing, it seems to have slipped, and the knot came out of place on the shaft.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#52
|
||||
|
||||
I finished replacing the main power supply filter caps which just leaves two multi-section caps to go. I figure that was good enough and decided to fire it up.
No smoke and I could hear the horizontal kick in. No raster though. I loosened up the anode cap and was able to draw a nice strong arc. Eventually, I noticed that the test CRT filament wasn't lighting up and touch up the pins with a soldering iron. That did the trick Unfortunately, I only seem to have horizontal deflection and I can heard some corona arcing inside the HV box but it's progress of sorts. Quote:
|
#53
|
||||
|
||||
Sort of. The string has a knot which fits into the center. I need to see which way it wraps around the shaft....clockwise or counterclockwise from the center, out.....
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#54
|
||||
|
||||
I think I'd need to remove the dial face to show that part ? Not so easy to do.
|
#55
|
||||
|
||||
Nope, just pull off the knob and give me a shot showing where the dial cord goes when it comes off the center of that geared shaft
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
Audiokarma |
#56
|
||||
|
||||
Do these help ?
http://www.flickr.com/photos/70039806@N00/11018689726 http://www.flickr.com/photos/70039806@N00/11018600645 http://www.flickr.com/photos/70039806@N00/11018846204 http://www.flickr.com/photos/70039806@N00/11018773616 Last edited by bandersen; 11-23-2013 at 07:46 PM. |
#57
|
||||
|
||||
Look at the second stringing diagram (page 6-8) in the Rider manual for RA-112:
http://www.earlytelevision.org/pdf/d...-rider-tv6.pdf I believe that's what I looked at when I restored my RA-113. My tuner had a busted gear, so I had to pull the mechanism completely apart, and somehow I got it back together correctly. Phil Nelson Phil's Old Radios http://antiqueradio.org/index.html |
#58
|
||||
|
||||
The vertical oscillator definitely isn't running and I've got some weird voltage readings on the osc tube. The plate is -55 volts but should be 70 Could be the boosted B+ line isn't working right.
|
#59
|
||||
|
||||
I discovered a loose wire in the B+ Boost circuit. Fixing that resulted in a raster
I rigged up a crude antenna and picked up this LPTV broadcast. The focus is terrible because the focus coil messes up the self focusing 8XP4 test CRT. Hooked up to an ATSC receiver / converted box. Zero audio. However, the FM radio reception is pretty good. It wouldn't be the first time a vintage TV didn't like my converter box. I dug out an unmarked, rebuilt 17" CRT and hooked it up. This is the best focus I could manage. Could be this CRT isn't compatible with this set or maybe the focus circuit needs some work. |
#60
|
||||
|
||||
Thanks for the pics and reference materials. I got it
Seems that the tuner was rewound incorrectly at some point, and the tensioner was stuck on the tuner shaft. Working now!
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
Audiokarma |
|
|