Old Muntz TV for sale Locally to me, Should I pick it up?

[vortalexfan]

Well I think as far as trying to get this thing going completely goes, I'm just going to replace all of the open and out of tolerance resistors in each circuit one circuit at a time and test the TV out after each section is done to see what the TV is doing after each section is done, that way if I get the TV to give a raster and what not midway through then I'll know by what sections I just completed replacing the resistors in that those sections were what was responsible for the TV's issues and I'll know that more than likely the rest of the resistors that I hadn't touched yet by that point will more than likely be fine to leave in place (unless they are 5% or 10% tolerance resistors which then in that case I would just replace those because of the fact that those tighter tolerance resistors are a little more important to the circuit's functionality than the 20% tolerance resistor are).

[vortalexfan]

I just put in a large order of Resistors to Mouser of all of the Resistors that I needed that to replace in the TV that I didn't already have in my stash, and it only cost me $22 and some change including 2 day shipping through FedEx. I really stocked up and got 20 of each one of the resistors I needed that I didn't already have in my stash, and that way most of the resistors worked out to be less than 10 cents a piece with some being less than 5 cents a piece.

[vortalexfan]

OK, so I figured out the mystery of the model number of this set and the one like mine that was in another thread on here.

Sam's DID actually cover this set, in Set 173 Folder 10, the actual model of this set is the Philharmonic Model 820! The exta zero was a typo on the model no. sticker and if you look carefully at the model number sticker the extra zero is actually crossed out, with a felt tipped marker.

So what this TV is actually is a Philharmonic Model 820 TV that was made by Meck Industries of Plymouth, Indiana.

So if anyone has a copy of Sam's 173 folder 10 that they could scan and upload that would be most helpful.

Also a little update on the repair process, I completely rebuilt the audio circuit in the TV and part of the sweep circuitry as far as replacing resistors go, and I'm still getting current draw in excess of 191 watts, and no vertical or horizontal or high voltage still, which I think I have narrowed my issue down to a bad 5U4 tube, which I think if I can just get a fresh 5U4G tube installed in the TV (instead of the questionable ones I have currently that were all redplated or close to redplated when they were ran when the TV had the shorted capacitors in it), I think the TV will start running fine.

The reason why I'm thinking this is because if none of the 5U4 tubes I have currently are strong enough to get the horizontal and vertical oscillators running then that would explain the excessive current draw, because as I understand it, if your vertical and horizontal oscillators aren't running then the TV is going to draw Excessive amounts of current because the vertical and horizontal oscillators when they run help to get the current draw down (at least that's how Shango has always explained it whenever he's worked on sets like this that have had excessive current draw.)

I guess I'll just have to test my theory and buy a NOS 5U4G tube from AES or one of the other tube outfits online.

[vortalexfan]

Yikes, I didn't realize how much 5U4 tubes are going for!

It seems I won't be getting a 5U4 tube for under $20 seeing as they go for between $25-$1,100 a pop!

[Electronic M]

I've had sets that with dead sweep oscillators and the outputs never drew enough to redplate or arc the rect.

I find my 5U4s for $10 a pop or cheaper at swapmeets.... Another option is to make a solid state 5U4 to with some silicon diodes.

[vortalexfan]

Originally Posted by Electronic M

I've had sets that with dead sweep oscillators and the outputs never drew enough to redplate or arc the HV rect.

I find my 5U4s for $10 a pop or cheaper at swapmeets.... Another option is to make a solid state 5U4 to with some silicon diodes.

I would like to try and keep this TV as original as possible since this is a rare early TV Set.

I'll keep checking around for cheaper 5U4G tubes.

Also don't you mean Low Voltage Rectifier? The 5U4 is the Low Voltage Rectifier, not the High Voltage Rectifier.

[Kevin Kuehn]

Originally Posted by vortalexfan

The reason why I'm thinking this is because if none of the 5U4 tubes I have currently are strong enough to get the horizontal and vertical oscillators running then that would explain the excessive current draw, because as I understand it, if your vertical and horizontal oscillators aren't running then the TV is going to draw Excessive amounts of current because the vertical and horizontal oscillators when they run help to get the current draw down (at least that's how Shango has always explained it whenever he's worked on sets like this that have had excessive current draw.)

I guess I'll just have to test my theory and buy a NOS 5U4G tube from AES or one of the other tube outfits online.

I guess you could also test that theory by pulling your vertical and horizontal output tubes and seeing if your current draw decreases substantially? I think it's highly unlikely that several 5U4's don't have enough snuff to power the circuits. This company has new 5U4GB for $12. Why not keep the rarer 5U4G's for after you get all the bugs out? http://www.abcvacuumtubes.com/vacuumtubes_tubelist.html

[vortalexfan]

Originally Posted by Kevin Kuehn

I guess you could also test that theory by pulling your vertical and horizontal output tubes and seeing if your current draw decreases substantially? I think it's highly unlikely that several 5U4's don't have enough snuff to power the circuits. This company has new 5U4GB for $12. Why not keep the rarer 5U4G's for after you get all the bugs out? http://www.abcvacuumtubes.com/vacuumtubes_tubelist.html

Well you have to remember that before I got the bugs worked out of the power supply I did most of those tubes pretty hard (to borrow InItForFun's words) .

Also when I pulled the Vertical and Horizontal output tubes the current draw dropped significantly from 194 Watts to 149 watts, so I think maybe the 5U4 is probably part of the problem, unless there's something else that I'm missing...

So an update, I do have HV and the Horizontal Oscillator is running again, and I think the vertical maybe running again as well, but nothing on the picture tube yet, (I flipped the TV on its side and turned it on and I heard the distintive high voltage buzz and I didn't hear that before).

Also something is still smoking R62 yet, but I think I figured it out, I think it might be R31 which is supposed to be a 27K Ohm 4 Watt resistor (2 56K Ohm 2 watt resistors in Parallel), which are out of tolerance as it only measures at 20k Ohms, that's the only thing I can think of that could be causing my R62 to smoke as that's the only other thing in the path of R62 in the circuit (I even traced it out on the schematic and nothing else was in the path of R62 that I saw of that could be causing R62 to smoke, unless there's something wrong with my 6AC7 tube that's causing it to smoke.

[vortalexfan]

OK so here's a video of what its doing currently.

Just follow the link below and it should take you to the video.

https://photos.google.com/photo/AF1Q...-sTDUuRGgsqv7t

[Kevin Kuehn]

Do you by chance have in your possession a working oscilloscope and the ability to look at the horizontal and vertical oscillator waveforms?

[Kevin Kuehn]

Originally Posted by vortalexfan

OK so here's a video of what its doing currently.

Just follow the link below and it should take you to the video.

https://photos.google.com/photo/AF1Q...-sTDUuRGgsqv7t

Link says I need to log into my google account, which I don't have, and don't want one.

[vortalexfan]

Originally Posted by Kevin Kuehn

Do you by chance have in your possession a working oscilloscope and the ability to look at the horizontal and vertical oscillator waveforms?

Yes I do, an old Tektronix 453 but have no idea how to use it, because it doesn't have its original manual anymore, it has all the attachments though.

and I guess I'll upload my video to YouTube so you can view it that way.

[Kevin Kuehn]

Originally Posted by vortalexfan

Yes I do, an old Tektronix 453 but have no idea how to use it, because it doesn't have its original manual anymore, it has all the attachments though.

Believe it or not that's a very common situation. Unfortunately I'm probably not the guy to teach you how to work your scope on line.

[Kevin Kuehn]

Found a pdf download of the manual for your scope. That's a very nice scope.
http://bama.edebris.com/manuals/tek/453/
The controls on those vintage scopes are all very similar, and really not as scary as you might first think.

[vortalexfan]

Originally Posted by Kevin Kuehn

Found a pdf download of the manual for your scope. That's a very nice scope.
http://bama.edebris.com/manuals/tek/453/
The controls on those vintage scopes are all very similar, and really not as scary as you might first think.

Yes, I did find that manual and downloaded it, and read through it, just not sure where where everything hooks up in regards to trying to find the waveform for the horizontal and vertical oscillator and what switches should be used and which ones shouldn't be used.