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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Mon 24, 2016 3:39 am 
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Joined: Jan Sat 31, 2015 10:06 pm
Posts: 413
Update: later this evening I put the chassis down flat and repositioned the picture tube so the HV cable reaches, intending to swap some tubes to see if the picture came back. Before I swapped any tubes, I powered the set on and - the picture was back. Not perfect, it was the non-horizontally-sync'd picture from before. But the all-gray problem was gone. Hmm. Something loose in he chassis, that may have shifted as I repositioned it? Fleeting problem that is now gone for good? Or an intermittent outage that I will never resolve and be tormented by forever?
Anyway, back to trying to fix the horizontal sync.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Tue 25, 2016 4:19 am 
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The other day thomas13202 mentioned that one of the new capacitors may have failed. Is this a not-unusual occurrence? I kind of assumed that the new caps would all be great and run fine for the rest of the set's, and my, life. Do the really sometimes go bad after a year of extremely light use? What's your experience with new cap failure rates?


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Tue 25, 2016 6:42 am 
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anything man made can and will fail. on top of that some new condensers can be bad right out of the box due to various reasons. especially condensers made in china do have known problems. i have no clue how likely it is but it is a definite possibility. they may be fine they may not check them.

If the Horizontal Hold control can cause the pic to slant one way or the other, it's doing its job and the H sweep gen stage is OKeh. You're just not getting sync pulses to it, and C511 and/or C513 are now prime suspects.

mr knox is a knowledgeable tec i would check the parts he mentioned. c511 and c513

do you have a television analyst? this is the easiest way to find the problem. if not and you know how to troubleshoot using a scope check if the sync pulses are present. i cant help you with scope troubleshooting as i have never used one for that but mr knox probably can along with other people here.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Tue 25, 2016 2:19 pm 
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Thanks Thomas. I will check those caps out when I get home I get my caps from justradios, the yellow ones. Probably all from China as so many things are.
I do not have a scope or a tv analyst. If you could recommend some specific models I can look into getting them. They would be a big help.
I used a scope back in high school.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Wed 26, 2016 4:49 am 
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Joined: Jan Sat 31, 2015 10:06 pm
Posts: 413
Tonight's activity:
- C511 - (new cap installed last year) unsoldered 1 end, jumpered in another new cap - no change. I replaced the existing one.
- C513A - (new cap installed last year) unsoldered 1 end, jumpered in another new cap - no change. I replaced the existing one.
- C516 - (this is an original suitcase cap) I'd tested this one in May but decided to try it again. I unsoldered one end, jumpered in a 2000 mica - picture was now worse - more slanted, more jumbled. Went into the "gray screen" mode a couple of times. Interestingly I found that banging on the lower right front of the chassis with a pliers had some effect, snapping it out of the gray screen and back to the (very jumbled, more slanted) picture, sometimes. With a plastic ball point pen I poked at various caps and resistors and tubes while the set was playing, but nothing jumped out as a loose connection or a cold solder. I eventually soldered back in the existing suitcase cap.

So now the picture is a bit worse. :(

Note: during the restoration I found some deviations from the schematic. I replaced the components, leaving the old repair but with new caps. i didn't do anything with them tonight, but I want to mention them in case someone thinks they're significant. Specifically:
- a 25/25 electrolytic across R539 / C513B. This is in addition to those two, and is not on the schematic.
- R534 - the schematic calls for a 100k resistor. Installed is a 68k resistor. It measures 87k in circuit. I found that in production run 3 this was changed to specify a 22k resistor.

Edit 10/28/16: corrected the C516 text here to reflect that I jumpered in a 2000 mica, not a 1000.


Last edited by sdyer on Oct Sat 29, 2016 3:41 am, edited 2 times in total.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Fri 28, 2016 4:50 am 
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Location: Ann Arbor, MI
On C516, does it have colored dots on it? If so, how are dots arranged and what are the colors?

Is the vertical sync as solid as it used to be? Try to remember how much you could rotate the control and still have it lock. And then see if is about the same now. If the vertical is now touchy where it used to be more solid then the problem could be earlier in the sync circuits than where you have been looking.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Fri 28, 2016 3:42 pm 
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Hi Tom - here is C516, the suitcase cap on the right.
Attachment:
File comment: The colors appear to be:
Top - black, red, black
Bottom - black, gold, red

C516.jpg
C516.jpg [ 48.09 KiB | Viewed 2603 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Fri 28, 2016 4:57 pm 
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Joined: Jan Sat 31, 2015 10:06 pm
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Here's something interesting I noticed with the L503 choke replacement I put in in May. When I hold the pliers up to it and away from it, the horizontal hold is affected. I'm not too concerned - it just seems to affect the resistance, which affects the hold, and adjusting any effect something's having on L503 is what the horizontal hold control is for. Still, this is an interesting effect. See latest video at https://www.icloud.com/sharedalbum/#B0f5n8hH4m5dr7
Attachment:
L503 Affected.jpg
L503 Affected.jpg [ 40.59 KiB | Viewed 2601 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 12:49 am 
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OK, that capacitor is a 2000 pf cap. So another change from the schematic.

Bringing any metal near a choke made the way that one is will change the inductance. So the effect that you are seeing in perfectly normal.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 3:14 am 
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Is that partial schematic of the sync section correct? I don't see that choke in it.

Another thing to try. Measure the voltages on the 7f8. Someplace the service literature should show the expected voltages. Post the voltages you get and what is expected. Also measure the voltages on the sync sep tube.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 3:40 am 
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Hi Tom - my post on C516 was incorrect. I jumpered in a *2000* mica cap - the one pictured below. My original notes (I keep notes on a pad as I go) show 2000. It was just my entry in this thread where I mistakenly transcribed it as 1000. I've edited that post to correctly read 2000. So C516 looks like a good, working cap at this point.
Attachment:
2000 mica cap.jpg
2000 mica cap.jpg [ 23.1 KiB | Viewed 2580 times ]

The schematic posted above is not the right one, now that I look at it closely. Below is the schematic I have, showing L503:
Attachment:
Horiz Schematic.jpg
Horiz Schematic.jpg [ 69.08 KiB | Viewed 2580 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 7:55 am 
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for the b&k television analyst the model i recomend is the 1075. this hasnt been made since the 50s. they also had a 1076 and 1077. i like the 1075 because it is all tube equiptment no solid state diodes or transistors. much easier to service when needed. ebay is the only place i know of to get a television analyst. the latest one made was the 1077 some time in the 1970s. unless you find one that has allready been serviced you will have to go through it to make sure everything works ok.

oscope i could not advise you on. i have no clue what a good one would be.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 7:35 pm 
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R505 was very high, R506 was open. I replaced both and - the H. Sync is working now. Whoohoo! I also replaced R537 which was reading high (105k, vs. 82k) which made a small improvement (I think) in picture quality. See the latest two videos at:
https://www.icloud.com/sharedalbum/#B0f5n8hH4m5dr7
They are of the Pet Shop Boys videos, and Burns & Allen.
Attachment:
Pet Shop Boys - Frame.jpg
Pet Shop Boys - Frame.jpg [ 41.49 KiB | Viewed 2558 times ]

Attachment:
Burns & Allen - Frame.jpg
Burns & Allen - Frame.jpg [ 43.93 KiB | Viewed 2558 times ]

Attachment:
R505 and R506 jumpered.jpg
R505 and R506 jumpered.jpg [ 113.38 KiB | Viewed 2558 times ]

Attachment:
H Sync Fixed 10-29-16.jpg
H Sync Fixed 10-29-16.jpg [ 82.09 KiB | Viewed 2558 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 8:16 pm 
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Great news! Congratulations are in order (and a cold beer if so inclined). Glad that you got it sorted out.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sat 29, 2016 11:04 pm 
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Good job!

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Sun 30, 2016 12:39 am 
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Greetings from FixitLand!

Glad you found the culprit! R506 being open would kill the plate voltage to the sync-separator stage, certainly killing the sync. But why you were still getting vertical lock is a mystery. Oh well — fixed now!

I also see I have the wrong schematic compared to your set. Online, I found the 48-1000 service manual which shows a quite different H sync section, but later on it lists a circuit change which closely resembles your schematic. Because I was seeing a different schematic, I likely was misleading you with different component numbers; my apologies!

Take care,

J. E. Knox "The Victor Freak"


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Mon 31, 2016 12:11 am 
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good job on the horizontal hold fix. congratulations on a job well done.

how is the cabinet coming along.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Oct Mon 31, 2016 1:36 am 
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Joined: Jan Sat 31, 2015 10:06 pm
Posts: 413
Hi Thomas - the cabinet is coming along well. I started a thread under cabinets, and one on a dedicated Philco site - I need all the help I can get.
http://antiqueradios.com/forums/viewtopic.php?f=7&t=307372&p=2591459#p2591459
http://philcoradio.com/phorum/showthread.php?tid=15588&pid=115687#pid115687
Briefly, I've been re-laminating the water-damaged wood. The first goal is structural strength, then I can strip it, put new veneer on, then refinish it. It involves lots of clamping:
Attachment:
Clamp 2.jpg
Clamp 2.jpg [ 86.01 KiB | Viewed 2504 times ]

There are many more pictures and details at the links above.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Nov Sat 05, 2016 1:49 am 
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Joined: Jan Sat 31, 2015 10:06 pm
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So now that the TV is basically operating, I'm working on getting it to operate better, both picture quality and sound quality. In this post I'll discuss current video issue number one: even though the sync is now stable, it still goes out sometimes. See the latest video (it is a DVD called "Gate to the Mind's Eye") - the sync goes out at 47 seconds, then returns at 1 minute:
https://www.icloud.com/sharedalbum/#B0f5n8hH4m5dr7
Here are a couple of frames from before it is lost, then after.
Attachment:
sync lost at 47 seconds - frame.jpg
sync lost at 47 seconds - frame.jpg [ 42.99 KiB | Viewed 2411 times ]

Attachment:
sync lost at 47 seconds - frame 2.jpg
sync lost at 47 seconds - frame 2.jpg [ 42.19 KiB | Viewed 2411 times ]

Any advice on what might cause the momentary dropout? Does it have something to do with the brightness of that scene? I always ask for advice before I start hunting through components and such, since I'm not really a TV repairman. :)


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: Nov Sat 05, 2016 2:13 am 
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Joined: Jan Sat 31, 2015 10:06 pm
Posts: 413
And now for some audio items.

Audio problem number one: The audio sometimes drops very dim. Changing the channel selector (the one on the TV itself) away from channel 4 (where I have the signal coming in) and back *sometimes* helps. In the past when I was poking around checking voltages, touching the circuits sometimes jolted the audio back to the proper level.
Does anyone have any pointers on where to start with this problem?

Audio curiosity: So I decided to start checking resistors, to solve the above issue. The first resistor is R200. The schematic calls for 220 ohms, a 3300 is installed, and it reads 4900 out of circuit. What?! I jumpered in a 220 ohm and - no effect at all on the picture. Perhaps a slight improvement, but so slight I might be imagining it. My plan is to just solder the resistor that was there, the high-reading 3300, since someone put there for a reason and it's causing not problems. But before I do - does anyone think I should put in the new 220 instead?


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