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#1
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I thought that might have been the case.
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#2
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Yeah, I thought of leaving them as they are. But then encapsulated them.
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#3
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The idea of couplets always intrigues me. When I used to repair colour TV's in customers homes back in the 70's there was a Thorn model 4KA set which used a similar component called a Thick Film Unit which was essentially a couplet. It used maybe half a dozen of them and they were notoriously unreliable. You'd replace one only to have it fail a week later. Made techs look like fools unfairly. Yours will last forever I'm sure.
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#4
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Quote:
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#5
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If you don't find an antenna I have one. It's out of a slender seventeener but I think it's the same.
The plastic bushing is rough but the antenna itself is good. yours for shipping if you need it. |
| Audiokarma |
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#6
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Thank you Eric. I have the bushings and all. Check your PM.
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#7
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I made a detailed post over on ARF about how I redid the knobs. So I thought I'd post that info here as well.
Here is what I did to the top knobs. I used the original knobs and cleaned them very good. This of course took off more of the letters/numbers. I tried using a black filler crayon to restore the letters/numbers. No dice. The indentations were very shallow. This must be the reason why the letters/numbers were so easily worn off. After that I lifted off the brass "bright" on each knob. It was glued but the glue broke free without much effort. After cleaning them I tried polishing them with Gorhams Silver polish. Like the rest of the TV, the brass plating was pretty much worn off too! I then sprayed on some primer, sanded it smooth and used my Bright Gold Rust-Oleum spry paint to get them back up to an acceptable level. I suppose I could have looked into getting them re-plated, but I thought the cost would be too high. Back to the plastic knobs. Once cleaned, I sprayed them with several coats of sandable primer. After they dried, I lightly sanded each knob "face" smooth. I then used some auto body galzing putty to fill what was left of the letter/number indentations. Then another 2 coats of primer sanded smooth. I then sprayed on several coats of Antique White Rust-Oleum spray paint. When dried overnight, I very lightly sanded the "face" of each knob till the paint was "level" and there was no sign of any "orange peel". I then made up some decals using my CAD program. I was able to match the font perfectly. I then ran my clear laser decal paper through my Brother laser printer. This prints the image onto the decal paper. I then applied a light coat of decal "bonder" by Testers. When dry, I applied a medium coat, then 3 more medium/heavy coats to the decals. I let them dry overnight. I then installed the "brights" with some glue and pressed them into position. I then carefully cut out each decal and applied them to the knobs. Carefully blotting out the excess water and smoothing the decals very flat. Again I let them dry overnight. I then fogged on several coats of the decal bonder over the entire knob. Then followed by several medium/light coats. Followed by several medium coats. When dry I installed the knobs. ![]()
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#8
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Great pictures of that transformer base! I repaired an identical one in a '62 Philco FM chassis. The rivet gets drilled out very carefully, then the caps can be removed. I put new caps under the PC board, not in the can.
I suggest disconnecting coils and measuring the pf value before removing it. I got lucky because an ex-Philco VK'er provided me with the values, which are not on the Sams or the Philco schematic.
__________________
"When resistors increase in value, they're worthless" -Dave G |
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#9
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Quote:
Are you saying that I should replace the caps? They looked good to me. |
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#10
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I used my 8YP4 test CRT and powered it up. After carefully checking B+ and filament string voltages, I powered it up to full voltage. I noticed that when the tubes heated up, the B+ would drop from around 270V to 140V. After some troubleshooting I found that L17 was open and not allowing B+ to get to pin 5 of V11 a 12AX4GTA Damper tube. I pulled the coil and sure enough one of the fine wires were broke off the main lead. An easy fix. Once done, B+ came up and stayed at 271V. Sams list it at 265V.
Here is what I was greeted to: ![]() I know the picture is bad, but I also have some tubes that tested bad that I haven't replaced yet till the weekend. All the controls did something so that's good. The filament string dropping resistor R59 was a 41 ohm 20W is now a 60 ohm 25W resistor that runs very hot. My spit sizzled when applied with a craft stick. Do they always run that hot? Do I need to go with a larger wattage? I went to 60 ohms because my line voltage is 122vac. Another thing I need some help with. I have no audio. The volume pot does increase and decrease the "hash" so I know downstream of the volume pot is working. I did some troubleshooting and found L14 the 1st IF coil is open. ![]() ![]() It's a simple coil and I have to pull the main board to either fix it (fingers crossed) or replace it. the Philco part number is 32-4644-12 with no other manufacturer listed as a substitute. I did try jumpering across the 2 terminals to short it out to see if that was the problem of no audio. Jumpering didn't help. I even heated up both terminals and re-flowed the solder, still no joy. I hoping that when I get some of the tubes replaced the picture and audio will be improved. As a long shot, does anybody have one of those coils? |
| Audiokarma |
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#11
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#12
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Quote:
Perhaps use a diode dropper for the heaters? 122v times 0.707 equals 86.25 volts... close enough to 88? jr |
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#13
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Could you explain what that is? I'm not familiar with those.
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#14
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That fly looks great! This was a common Philco issue and one of my sets like this has its fly covered in clear silicone.
Also, the yoke cover reconstruction may be the first one done on this forum.I was considering trying to "print" using a 3D printer but not sure the polymer would stand the heat in this application. An .stl file also needed to be created, which stopped the project.
__________________
"When resistors increase in value, they're worthless" -Dave G |
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#15
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Great work Crist.
I have 3D printed a simpler yoke cover to replace a disintegrating one in a Zenith and I have had no problem with the heat from the CRT.
__________________
Tim |
| Audiokarma |
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