Hi all,

Im looking to start on the Philco TV I picked up at the ETF in Hilliard.

I need a few tubes to get it going, some where missing some tested bad.

I need the following tubes;
6SN7 2x
12AU7
6AU6

Also the speaker cone is trashed so i think I am going to need a speaker.

The flyback looks good and at the ETF had a chance to test the 12JP4 which tested near 100% in emission/life test. It also looks like someone started recapping in the 70's.

Any help would be appreciated.

Matt

What's the problem with getting those very common tubes? If you insist on buying
them in person, rather than by mail, just go to any decent hamfest around your area.
Good luck with the project!

I am strictly lo-fi so I don't know much about tube audio, but the 6SN7 & 12AU7 are desirable enough to audiophiles that I don't have any spares. Seem to be plenty of 6AU6s, though!

I have a similiar Philco and had to go through a half dozen 6SN7s in the vertical circuit before I found one that would work. The tubes checked okay, it was just that this set was very picky.

Matt;
PM in Private I'll send some tubes to replace what's missing:yes:with address:banana:
Jody....driving 2.5 tons of Antique post-war Mopar Fun:banana::banana:

Thanks to some Video karma members and Just Radios, i have started work on the Philco TV.

The first thing was to clean up the chassis, then insert all tubes except the 5U4 rectifier tube so could power up without the HV. So i ran up the variac up slowly over like 45 min just to see if the tubes lit and the power trans did ok without heating up.

After that went ok i inserted the 5U4 and did a slow power up over an hour and a half and was rewarded with a raster.

After that and getting schematics and a service manual I ordered replacement caps form Just Radios, they did not have all the cap values i needed but i decided to place the order to get started.

The caps came in on Thursday and i decided to take time this long weekend to start recapping in stages, replace 5 then power up to make sure no harm was done.

Here are some of the picts of the first power up, the recap and the progress

Final set of picts for today, showing the progress. First pict is the first semblance of a picture I got after hooking the LaserDisc player up through RF, the second one is after

That is some good progress you got there!

Those round tube Philco sets make one of the best pics out there, IMO. The one I had gave a very sharp picture, great detail. I had to have more than 4Mhz video bandwidth, but mine was a split chassis.

After quite a few more old junky capacitors where replaced, here are some more progress picts. The first one is the underside, an the second is the picture I got after the latest round of cap replacements.

The video comes form a Pioneer LaserDisc player with the RF modulator set to channel 4. The disc is LaserVision Demonstration II. A very high quality Japanese produced LD. Using 35mm film Betcam SP tape and HiVision videotape sources.

Woooow!

Hi all,

After replacing caps and making progress, resistors started going bad... Some i broke the leads off of when replacing other caps, the wire seems very fragile. Other caps started drifting badly the more the set was used. So Started replacing the larger higher power resistors first.

Now I am having issues with the horizontal locking in, it gets close but will just not make a nice straight picture without waving. I noticed that there are horizontal frequency and horizontal stability controls and wondered if I might start there.

Also I would love to take a scope to this thing and make sure my waveforms are correct, but there is a big problem and that is the CRT and yoke are mounted permanently in the cabinet, so if I take the chassis out I have nothing to connect it to...

Using a LaserDisc player as my source, have attached a picture of the effect. It is Jose Caracas singing.

Once the electronics are done I am not sure what to do about the photo finish which is badly marked in places.... but working order electronics are the order of the day first.

Matt

Well lets try the picture again.

Hi all,

First of all I would like to thank all of you who have helped me on this set. Some things got in the way so it was on the back burner, digging back into it soon and I have a question, I was told to replace all of the mica caps in the horizontal and vertical section as i can not get things to stay stable and all other paper caps have been replaced. For the replacements what type of capacitors should I order.

Matt

I replace mica with mica, available from http://www.mouser.com/ (and other suppliers).

Have you worked through the horizontal adjustment procedure in the Sams manual? I'd try that before replacing more capacitors.

If that doesn't help and your problem is limited to horizontal (that is, you have good vertical stability), then I'd replace only the horizontal caps and see where that gets you.

Phil Nelson

The service notes have a horizontal set up procedure using a basic scope. There is a test jack so you can do it from the top of the chassis.

"Bends" are usually caused by leaky sync coupling caps or shorted IF tubes. Check those first.

Well,

I am back at working on the TV after a long break. Went to work on it las night and it looks like I have no HV, today i took the cage off, there is a large brown/black spot on the 6GB6 Horz output tube and when in operation I see what looks like HV inside the tube it has a slight blue ionized glow inside. So I am thinking that the tube is bad, I do not currently have a tube tester, as it was borrowed and I had to give it back.

I also started gluing parts of the cabinet back together that where separating.
Matt

Make that 6BG6....

Check the HV rectifier (1B3 I think) in the cage. The glow in the horizontal output, unless extreme is usually normal. Disconnect the plate cap with the set off, on the 1B3 and carefully position it away from everything, turn it back on and use a WELL INSULATED srewdriver placed near the cap to look for a arc to come from it. If you get the arc, the 1b3 has gone bad. For some reason I find HV rectifier tubes die shortly after they are returned to service. My T-933 Maggie and my Zenith N chassis both did that. Just be careful when using this test. No grounding the screwdriver and fingers on the far end of the handle.
No arc, check the negative voltage on the control grid of the horizontal output tube. Low or no voltage means no oscillator. Normal, check the 6BG6 and the damper.
Does this set have a horizontal drive control?

Hi,

I checked and got no arc, the 1B3 is a post 68 RCA. When i measure the negative voltage on the grid it is -0.9 sam's says it should be -4. Yes it does have a drive trimmer.

I am measuring with the fluke 28 FM in the DC range with the negative lead clipped to a spot on the chassis and the positive to the test point.

Matt