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#31
09-21-2010, 11:43 PM
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Nice job repairing the CRT base
 I imagine you have a few bad caps too. Those are some funky looking light bulbs. Are they specialty or vintage bulbs ? 
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#32
09-22-2010, 12:23 AM
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The large ones are "industrial service" lamps. I got them at the U of M salvage store for $0.10 per pack! They had some nice 1980s 25w lamps too, some from ITT and some GE ones with a picture of Edison on the side of the carton.
-J
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#33
09-28-2010, 08:26 PM
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So I played with the set some more tonight. I left it sit for a couple hours with just a 40w lamp in the tester, giving the tv about 30 volts. I then put the big lamps back in, and heard scanning! I plugged the set into line voltage, and amazingly there was sound! Not just static, but an actual broadcast! I guess there's still some analog transmission in this area.
The picture is very wrong. It does seem to change with the channel selector, but not much. The upper half is dimmer then the lower half. There's also a very noticeable high pitched sound. I don't know if that's normal for older sets, but I have good hearing and can pick up a modern set when it's left on with no picture. I turned the set off for a moment while I got a light so I could read the controls, but when I powered the set back up there was no picture, no high pitched sound... just audio. EDIT: The station is from across the border... CBC on channel 9. The audio stages work perfectly, the set has fantastic sound. -J Last edited by compu_85; 02-19-2011 at 12:03 AM.
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#35
09-28-2010, 10:09 PM
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The worst is over. You have a raster, the CRT works, the HV flyback works, the yoke works. Now as suggested, some paper capacitor replacement and electrolytic capacitor replacement will quickly bring this old girl back to life.
Top of the picture may look dark because the scan lines are so far apart. Vertical linearity is way off but that could have been from someone monkeying with the control or more likely, bad caps in the vertical section. Congrats and welcome aboard Mate!
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#36
02-18-2011, 02:08 PM
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So I'm going to the electronics store today to buy caps. Looking through the pictures in the schematic I noted all the ones that looked like paper. In the parts list I notice some of the caps have a voltage listed, some do not. Why is this?
EDIT: looks like the paper ones are the ones with a voltage rating. Easy enough. -J Last edited by compu_85; 02-18-2011 at 02:23 PM.
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#37
02-18-2011, 06:52 PM
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Yes just start with electrolytics and paper caps and see what that buys you. Don't worry about micas as yet, since you may get very good results by just changing these out. Keep us posted!
Gilbert
__________________
I don't know anything about ignorance and I could care less about apathy. www.galaxymoonbeamnightsite.com
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#38
02-18-2011, 07:12 PM
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I've gotten the chasis out, there's trouble in river city. Looks like I was too hasty in my initial powerup, the vertical output fuse (.3 amp) is blown. The flyback also looks like it got toasty at some point and dripped a bunch of wax into the bottom of the cage.
I didn't have the set running very long when I got a picture, and I've never smelled any bad smells from it, I wonder if the flyback melted years before? Someone was nice enough to scan the Sam's for my set, but I think it's missing a page in the schematic section. :/ -J
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#39
02-18-2011, 11:27 PM
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So how fatel does this look?
The lead going to the top of the HOT had a very shoddy repair done to it, the last few inches of the wire had been changed to lamp cord with a very poor solder job on the tube connector. The part where the wires were joined fell apart. It may have just been twisted together with a single turn of electrical tape to cover it. Doesn't that wire cary very high voltage? Can I replace the damaged end if I use good wire and cover it with layers of heatshrink? Start of the evening. I don't think a single part has ever been replaced. A few hours later, a bit of progress. So far the caps match the Sam's. I was annoyed when I found the modules were soldered in place, but less annoyed when I found you can reach most everything through holes in the chassis. Now that I've supported my local electronics store, I think I'll get the remaining caps online. Electronic Connection seems to add a ~$2 markup per cap  -J Last edited by compu_85; 02-19-2011 at 12:00 AM.
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#40
02-18-2011, 11:46 PM
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One more question... I need to clean between the CRT and the safety glass. What's the best way to get the CRT out of the cabinet safely? Lay the whole thing down on its front and get a helper to help grasp it by the mounting ears?
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#41
02-19-2011, 12:53 AM
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Yes, that is usually a good method. The Photofact manual my have a CRT removal/replacement procedure in it as well.
__________________
Chris Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did."
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#42
02-19-2011, 09:08 AM
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I'd plug away and finish replacing capacitors, and then worry about the rest.
Don't forget the electrolytics. I usually do them first, since the rest of the TV is pretty irrelevant if you have a crippled power supply. It would spoil your day if a filter croaks and burns up your power transformer. A little dripped wax under a flyback is common and not a horrible sign in itself. I have sets in that condition which play reliably. The HOT lead may be ugly, but it's working well enough to display a full raster. Like the dirty safety glass, I'd leave it until later. Once you have a sharp, brilliant picture with strong audio, you can worry about such details. Regarding new non-polarized caps, to make life simple I usually buy everything with a 630V voltage rating even if the original was rated lower (200V, 400V, whatever). When manufacturers were ordering in huge quantities, they could save money by using the lowest-rated cap that worked in a given circuit. You are not buying in bulk and a cost difference of one or two pennies is not worth your attention. Have fun! By coincidence, I recently got a couple of 1957-1958 sets (one RCA, one Philco) and both have triple speakers. They're not in a condition to compare, but I suspect RCA might win a Pepsi challenge, as it has a crossover network with tweeters & woofer, not just three speakers wired in parallel. Let me know if you're still missing a schematic page. I can download many Sams for free via the local library subscription. Phil Nelson Phil's Old Radios http://antiqueradio.org/index.html
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#43
02-19-2011, 09:29 AM
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Quote:
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#44
02-19-2011, 09:58 AM
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Quote:
For a while I removed all the high voltage tubes and used the set as an amp for my phone playing Pandora. My set also has the 3 speaker setup w/ a lill crossover. It sounds fantastic. It has descent power too, on the bassy stuff it had enough umph to make the grille cloth vibrate visibly. I'm hoping it sounds even better after the recap, the higher you had the volume the brighter the audio got. The HOT lead fell apart as I moved the chassis. So i'll need to repair it before I power things up again. If you could nab me a copy of the diagram I'd be very appreciative  Looking through this one there are no directions for removing the CRT or safety glass, just removing the tuner and chassis. Whoever put in the crt was sloppy, the nuts were hardly finger tight and are 3 different sizes  -Jason Last edited by compu_85; 02-19-2011 at 10:07 AM.
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#45
02-19-2011, 12:36 PM
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I have the Sams (folder 346-11). If you send me a PM with a regular email address, I'll email it to you.
You might want to edit your very first post in this thread. The label on your back cover says 21-D-7447 but your post gave a different (nonexistent) model number. The HOT lead falling apart is clearly an omen telling you to replace the electroytics before tempting fate again Phil Nelson
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