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

[Kevin Kuehn]

Well that's a good starting point. Can those bar magnets be centered in the clamp doohickey so they are the same position on both sides? Not sure how much that will help. I need to sleep on this, not sure off hand why the brightness would need to be in a center position. There's also the possibility that someone has had that trap off the neck and it needs to be reversed front to back. Some traps have an arrow that indicates the end to be pointing forward.

[vortalexfan]

Originally Posted by Kevin Kuehn

There's also the possibility that someone has had that trap off the neck and it needs to be reversed front to back. Some traps have an arrow that indicates the end to be pointing forward.

Yes there is an arrow on this Ion Trap and its facing forward towards the front of the picture tube, also I did adjust the focus adjustment knob and I got a much clearer picture than before.

I also can't seem to get the vertical and horizontal hold to lock in, and is it normal to be able to hear the vertical oscillator through the speaker on the TV?!

[Kevin Kuehn]

Originally Posted by vortalexfan

I also can't seem to get the vertical and horizontal hold to lock in, and is it normal to be able to hear the vertical oscillator through the speaker on the TV?!

No you can't get the raster to lock unless there's a sync pulse from composite video signal being detected. Right now the horizontal and vertical oscillators are free running. You should have the ability to make the vertical roll up or down, just won't lock in. I'd say the vert oscillator sound is normal because you probably have the volume cranked with no audio signal to detect.

[vortalexfan]

Originally Posted by Kevin Kuehn

No you can't get the raster to lock unless there's a sync pulse from composite video signal being detected. Right now the horizontal and vertical oscillators are free running. You should have the ability to make the vertical roll up or down, just won't lock in. I'd say the vert oscillator sound is normal because you probably have the volume cranked with no audio signal to detect.

Well I hooked a converter box up to the tuner and I'm not anything on the tuner, no audio, no video, nothing, and I'm not even getting any snow on the screen, or white noise from the tuner, when I go through the channels or adjust the fine tuner knob, all I'm getting is the sound of the vertical oscillator through the speaker that's it, no white noise, nothing.

[Kevin Kuehn]

Originally Posted by vortalexfan

Well I hooked a converter box up to the tuner and I'm not anything on the tuner, no audio, no video, nothing, and I'm not even getting any snow on the screen, or white noise from the tuner, when I go through the channels or adjust the fine tuner knob, all I'm getting is the sound of the vertical oscillator through the speaker that's it, no white noise, nothing.

Time for more voltage measurements. Does your tuner match that of the sams folder you've been using, a single 6AG5 and 6J6? If so verify that your DC pin voltages match what Sams call out for V1 and V2, from the voltage chart on page 8.

For anyone following here's the tuner portion of the Sams 101-5 schematic along with the voltage chart.

https://live.staticflickr.com/65535/...38a31f87_b.jpg

https://live.staticflickr.com/65535/...ec92c010_b.jpg

[vortalexfan]

Originally Posted by Kevin Kuehn

Time for more voltage measurements. Does your tuner match that of the sams folder you've been using, a single 6AG5 and 6J6? If so verify that your DC pin voltages match what Sams call out for V1 and V2, from the voltage chart on page 8.

For anyone following here's the tuner portion of the Sams 101-5 schematic along with the voltage chart.

https://live.staticflickr.com/65535/...38a31f87_b.jpg

https://live.staticflickr.com/65535/...ec92c010_b.jpg

Yes, my TV has the 2 tube tuner in it.
Although I don't have any 6AG5 tubes so I subbed it out with a 6AK5 tube.

I'm assuming I can take the voltage measurements through the top of the tuner's tube sockets with the tubes removed?

[Kevin Kuehn]

Originally Posted by vortalexfan

Yes, my TV has the 2 tube tuner in it.
Although I don't have any 6AG5 tubes so I subbed it out with a 6AK5 tube.

I'm assuming I can take the voltage measurements through the top of the tuner's tube sockets with the tubes removed?

No the tubes definitely need to be installed, so I suppose that's going to be difficult unless you have one of the test socket adapters. You might be able to push the pins only partially in the socket and probe the sides of them. Maybe Old Coot will have a better idea on where to go next. I was going to suggest that you check for change in AGC voltage when you connect your signal source to the antenna input vs no signal, if so that would indicate that signal is getting though the tuner and video IF and at least as far as the detector. AGC voltage should go more negative with stronger signal. Great to hear the HV rectifier solved your brightness issue.

[vortalexfan]

OK so here's the measurements I got from the tube sockets on the tuner in the TV:

6AG5:

What it should measure:
Pin 1: -.2 VDC
Pin 2: 0 V
Pin 3: 6.3 VAC
Pin 4: 0 V
Pin 5: 145 VDC
Pin 6: 130 VDC
Pin 7: 0 V

What I measured:
Pin 1: -0.6 VDC
Pin 2: 0 V
Pin 3: 6.8 VAC
Pin 4: 0 V
Pin 5: 83.3 VDC
Pin 6: 82.3 VDC
Pin 7: 0 V

6J6:

What it should measure:
Pin 1: 110 VDC
Pin 2: 83 VDC
Pin 3: 0 V
Pin 4: 6.3 VAC
Pin 5: -2 VDC
Pin 6: -6 VDC
Pin 7: 0 V

What I measured:

Pin 1: 80 VDC
pin 2: 74.5 VDC
Pin 3: 0 V
Pin 4: 6.8 VAC
Pin 5: .2 VDC
Pin 6: 0 V
Pin 7: 0 V

So it looks like some of my critical voltages for the tuner are a lower than they should be.