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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Wed 06, 2015 8:13 pm 
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The reason that I mentioned that it should be grounded is just because it forms one plate of a capacitor, as does the metal mounting structure around the CRT. If it is not grounded then it can end up with almost the full high voltage on it. Now, since the capacitance is fairly low, you will not get electrocuted if you touch it. But you could end up using excessively strong language and might bump and break something.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Wed 06, 2015 9:02 pm 
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I will make sure the picture tube frame is grounded to the chassis before I crank up the voltage on the variac. I certainly don't want to risk saying $@#!, or %&!!#.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 12:25 am 
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You can see the springs inside the bracket contacting the CRT, I'm pretty sure there's a wire going to the chassis as well, but just to be sure I'd put a jumper on it.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 2:57 am 
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I epoxied the top contact back on that tube where it came off, posted way above. The tube tested well last week, when I had all the tubes tested, with the cap just pressed on. I tried some solder, but that wasn't going to work. I wicked most of it off with the soldering iron, then just glued the top with some epoxy around the edges. Hopefully it's still connecting. I also fixed the speaker.
Attachment:
File comment: This cap will never move again.
6BG6G - Epoxied the top back on.jpg
6BG6G - Epoxied the top back on.jpg [ 46.17 KiB | Viewed 3537 times ]

Attachment:
File comment: Repaired the speaker with coffee filter and rubber cement.
Speaker Repair.jpg
Speaker Repair.jpg [ 48.49 KiB | Viewed 3537 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 3:55 am 
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After I put the tubes all back, the shields for the little tubes looked lousy. I soaked them in Heinz white vinegar for 24 hours, now they're completely rust-free. Now it's looking sharp.
Attachment:
File comment: Soaked for a day, then scrubbed them with a scrubber sponge.
Heinz White Vinegar, 24 hrs.jpg
Heinz White Vinegar, 24 hrs.jpg [ 50.79 KiB | Viewed 3532 times ]

Attachment:
File comment: Much better.
Clean.jpg
Clean.jpg [ 63.49 KiB | Viewed 3532 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 4:44 am 
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Location: Wyoming, Michigan
My cat is sitting on my lap as I write this. I can stroke her back a couple of times until her hair starts crackling. Now the electrical potential between us is about 22,000 Volts. I touched her nose and it discharged. Neither of us swore or broke anything. Even at twice the "full voltage" of your CRT.

The current flow through the CRT glass is negligible. The HV feeding the anode of the CRT has to be at a current level high enough to light the phosphor on the screen. The "full Voltage" here is the one that many of us have accidentally touched and have been led to swearing or breaking something. That level of current can't pass through the glass wall of the CRT. Apples and oranges. By all means ground the CRT mount if you wish to enable the noise filtering of the outer graphite coating but, again, it's not a safety issue, x-ray or electrocution. Or even swearing or breaking things.

It's good to respect and fear electricity when warranted. And better safe than sorry I guess. But fear can diminish with knowledge, and unwarranted fear can lead to paralyzing timidity and inaction. Or just missing out on things.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 4:53 am 
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Location: Wyoming, Michigan
The vinegar bath will leave the tube shields "raw" and very susceptible to flash rusting rather quickly. I would burnish them with 0000 steel wool and then apply some sort of protectant. Liquid car wax or maybe WD40 or something.

I don't think the epoxy will stay solid at that tube's operating temperature. Will at least start bubbling or even smoking. Might make a mess.

All in all you're doing great. My advice can be taken or left as you see fit. Sometimes I just like to rant. Excellent progress and good photos and feedback.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 4:59 am 
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Is that the horizontal output tube that you glued the top back on? If so, that one gets very hot, and your epoxy is going to basically burn. You'll want to make sure you have a good soldered connection, since a poor connection at that point can cause problems for the tube.

What I do with these is the following: Heat the cap with a soldering iron, and shake off all the old solder. Now gently punch down the center of the top so it pokes inward a bit, with the hole at the bottom of your "dip." If the hole isn't visible, use a tiny drill to make one, or punch a tiny nail through it.

Then scrape the wire coming out of the tube to get it nice and shiny, and pre-tin it with a bit of solder so you can see it is sticking properly. Then poke the wire through the hole in the cap (your newly formed dip makes sure at least some wire comes through) and solder securely, basically burying the wire tip in a dome of solder.

This will not be mechanically strong, but the electrical connection will be good. Install the tube with some care so that you don't put any stress (except pure downward force) on the tube cap, and it will stay connected.

If you want to add some kind of adhesive to secure things better mechanically, use silicone caulk, since it can tolerate very high temperatures (just like a silicone hot holder or oven baking sheet). It's a bit rubbery, but in a thin gap it will hold things OK. Epoxy will tend to burn (although there are epoxies that can tolerate plenty of heat if you special order them), and Super Glue will let go almost immediately (it can hardly even tolerate 140 F, and your tube will run a lot hotter than that).

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 5:52 pm 
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I have my fingers crossed on this one.

Not that I believe in luck.

"Luck is the by-product of good planning." Henry J. Kaiser.

Do you have a variac? 8)

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Thu 07, 2015 6:19 pm 
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I do indeed have a 3A Variac. I've got to fix up the epoxied tube, then I can give it a try. Should be soon!


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Fri 08, 2015 3:14 am 
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I fixed the cap per on the 6BG6G per Tom's instructions. Worked like a charm! I heated the epoxy with a heat gun, then once it was a bit soft I pried the cap off with an X-acto knife. Then I used a small nail to poke a hole in the cap, and then a bigger nail to widen it. Finally I put the cap on, with the wire just about at the opening, and soldered it. Photos below. Thanks Tom!
Attachment:
File comment: Step 1 - put a hole in the cap.
Hole.jpg
Hole.jpg [ 60.04 KiB | Viewed 3471 times ]

Attachment:
File comment: Step 2 - put cap on, make sure wire is in a good position to be soldered. (Apologies for the blurry pic.)
Wire in Hole.jpg
Wire in Hole.jpg [ 37.67 KiB | Viewed 3471 times ]


Attachments:
File comment: Step 3 - older the wire to the cap.
Soldered.jpg
Soldered.jpg [ 37.62 KiB | Viewed 3471 times ]
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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Fri 08, 2015 3:19 am 
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I turned on the power. This was done without the unit hooked up to any kind of video source. I ramped the Variac up slowly, eventually to 115. Results:
- tubes glowed (mostly)
- 6BG6G was arcing - it had a purple glow inside
- picture tube glowed at the base, but no activity on the screen
- Outer 5U4G didn't glow
- Speaker buzzed softly
- No change in glow/buzz/picture tube when I fiddled with the knobs on the front
After I saw the arcing I turned it off. I turned it on again to get the picture below, and this time the outer 5U4G *did* glow. 6BG6G was still arcing - you can just make out the purple glow in the pic.
For the arcing tube - should I replace it? Or could it be due to some wiring issue, resistors, etc.? I don't want to leave it powered for any length of time until that is fixed. After that, I can get into troubleshooting this monster.
Attachment:
File comment: These things haven't glowed since the 60's or earlier, probably.
First Power.jpg
First Power.jpg [ 28.76 KiB | Viewed 3471 times ]


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Fri 08, 2015 3:43 am 
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If the purple glow in the 6BG6 is on the inner surface of the glass that's okay, it means the tube is conducting, possibly too much if the Horizontal oscillator isn't running.

If the glow is inside around the plates then the tube is gassy and no good, the arcing makes me think this is probably the case. If the Horizontal oscillator isn't running the 6BG6 will overheat in short order and self destruct, possibly this was the source of the arcing?

A quick test for the oscillator is to take a screwdriver with a well insulated handle and bring it up to the cap of the 6BG6, if things are working as they should you will get a small purple arc to the blade of the screwdriver (do not ground it!), if that is working move the screwdriver to the cap of the 1B3 HV rectifier tube, you should be able to draw a larger purple arc from that to the screwdriver.

When you say the 5U4 didn't glow are you referring to the heater? If that's not glowing it could only be a bad tube or a bad connection with the socket.

Maybe it's just the picture but I don't see the heater glowing in the Damper tube and several others? Possibly a bad connection feeding part of the heater circuit? I think the Damper is on it's own heater circuit though.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Fri 08, 2015 3:50 am 
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The circled tube doesn't appear to be lit (or maybe I can't see it through the getter?), that's the Horiz oscillator, if it's not lit there's no way it will have high voltage.


Attachments:
osctube.jpg
osctube.jpg [ 10.3 KiB | Viewed 3468 times ]
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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Fri 08, 2015 5:09 am 
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A way to determine if the horizontal oscillator is running is to measure the voltage at the grid of the horizontal output tube (6BG6). If you get 20 volts or more negative, then the oscillator is running. If you get around 0 then it is not running. If it is not running, remove the 6BG6 from the set while you trouble shoot the oscillator. With the 6BG6 removed, you can take your time doing voltage measurements. Note though that you can only check for a negative grid with the 6BG6 installed. Another way to remove power from the horizontal output circuit (to avoid overheating the 6BG6 and horizontal output transformer (flyback)) is to remove the damper tube.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 09, 2015 11:44 am 
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Location: Wyoming, Michigan
The purple glow of a gassy tube is more of a magenta color, the purple glow of a normally operating 6BG6 is more of a royal blue to ultraviolet (aka "black light"). The glow in your photo is appears to be the latter.

I would strongly urge you to perform the Sams resistance checks per the chart provided. Everyone here skips that step for reasons unknown but it's 101. It's tedious and time consuming which I guess is a turnoff but a lot can be learned by doing them.

Gently rocking each tube in its socket while the power is on may lead you to discovering a dirty socket or two which may explain why some of the tubes don't light.

This is the phase that separates the men from the boys. Chin up and patience.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 09, 2015 11:53 am 
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Location: Wyoming, Michigan
The screwdriver and arc trick is the level of current that causes swearing and breaking things. Usually harmless but a safer method is to place the glass of a CFL (curly-fry) household light bulb very close to the cap of the 6BG6. If the HV is working, the bulb will light brightly. If this occurs, look next at the ion trap magnet placement for reason why the CRT isn't lighting.

Again, this all should be done after resistance checking per Sams chart.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 09, 2015 12:05 pm 
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YouTube example: http://m.youtube.com/watch?v=Gas1GMPMa3g


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 09, 2015 2:57 pm 
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I've determined that the 6BG6G glow is the normal blue, not the gassy purple. Let me know if you think otherwise. All tubes lit up, none are dead.

I hooked up an old VHS player to see if I could get sound - I did. The sound was very dim, and adjusting a variety of controls affected the sound, not just tone/volume controls, but I did hear PeeWee's Playhouse coming through. (Slim pickins on VHS tapes at my house, and all I could find is an old tape of that show from the 80's. I ordered a VHS of music videos to test with - something with constant sound, and that I know what it should sound like.)

Still nothing on the CRT. I tried fiddling with all the knobs, nothing had any effect. I'm wondering how tight the HV connector to the tube should be. It's all the way in, but is not "locked" in or really very tight. It won't fall out, but could that be an issue?

The CFL test failed. So, I'm going to poke around underneath and see what I can find in the HV circuits.
Attachment:
File comment: Normal?
6BG6G Glow.jpg
6BG6G Glow.jpg [ 18.3 KiB | Viewed 3407 times ]

Attachment:
File comment: How tight should this be?
High Voltage Connector.jpg
High Voltage Connector.jpg [ 42.54 KiB | Viewed 3407 times ]

Attachment:
File comment: This is a working bulb, but no light here.
No CFL Light.jpg
No CFL Light.jpg [ 73.83 KiB | Viewed 3407 times ]


Last edited by sdyer on May Sat 09, 2015 3:33 pm, edited 1 time in total.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 09, 2015 3:32 pm 
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Before "poking around" in the high voltage circuitry, I read up on safety. http://www.repairfaq.org/sam/captest.htm#ctsdc talks about how to discharge capacitors. In the radios I've worked on, I just used an alligator cable across the leads. I've never had any snap, crackle or pop of any kind. For the TV, should I use something with a resistor? Do I need many dischargers of varying resistances for the various caps? Is it only the electrolytics that need discharging, or the others as well?
What other safety precautions do you all take?


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