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

[vortalexfan]

Originally Posted by Kevin Kuehn

Just out of curiosity, how many DC volts do you measure from pin 2 of the 5U4 to ground? And from pin 5 of the 6W4 to ground? Before measuring take a look at the voltage chart(page 8) in your Sams so you have an idea of what to expect.

I'm assuming the set will be powered up for this procedure?
Also will the tubes be removed for this or are they still in the sockets?

[Kevin Kuehn]

Originally Posted by vortalexfan

I'm assuming the set will be powered up for this procedure?
Also will the tubes be removed for this or are they still in the sockets?

Yes powered on with tubes in sockets.

[vortalexfan]

Originally Posted by Kevin Kuehn

Yes powered on with tubes in sockets.

OK well a little problem, when I was replacing some of the capacitors I replaced a couple of .05 MFD capacitors with what I thought were some .047 MFD capacitors but then when I looked at the code on it again I realized it said 472 rather than 473 on it so right now I really can't power on the TV because of it having the wrong value of capacitors in a couple of spots.

I do have a list of the capacitors I need though drawn up, including the electrolytics I didn't replace yet, and interestingly enough this TV uses all of the basic capacitor values like .1, .01, .047, .0047, and .033 (which actually the last one is .035 but .033 will work fine I in its place I think).

[old_coot88]

Before investing further effort and $$ in that set, it'd be advisable to check the no-load current draw of the power xfmr, considering the xfmr has a history of being brutalized over and over.

Remove all the tubes (except HV rect), disconnect CRT from its socket, power up and measure AC current draw from the wall. This 'idle' current should be very low. If it's excessive, suspect some cooked windings in the xfmr.

[Tube TV]

Originally Posted by old_coot88

Before investing further effort and $$ in that set, it'd be advisable to check the no-load current draw of the power xfmr, considering the xfmr has a history of being brutalized over and over.

Remove all the tubes (except HV rect), disconnect CRT from its socket, power up and measure AC current draw from the wall. This 'idle' current should be very low. If it's excessive, suspect some cooked windings in the xfmr.

Yes agreed this would be a excellent plan.
Lets hope that the flyback isn't cooked.

[old_coot88]

Originally Posted by Tube TV

Lets hope that the flyback isn't cooked.

The fly shouldn't be affected since it was not in the current path of the B+ short.

[vortalexfan]

Originally Posted by old_coot88

Before investing further effort and $$ in that set, it'd be advisable to check the no-load current draw of the power xfmr, considering the xfmr has a history of being brutalized over and over.

Remove all the tubes (except HV rect), disconnect CRT from its socket, power up and measure AC current draw from the wall. This 'idle' current should be very low. If it's excessive, suspect some cooked windings in the xfmr.

OK, that's easy enough to do.

[vortalexfan]

Originally Posted by old_coot88

Before investing further effort and $$ in that set, it'd be advisable to check the no-load current draw of the power xfmr, considering the xfmr has a history of being brutalized over and over.

Remove all the tubes (except HV rect), disconnect CRT from its socket, power up and measure AC current draw from the wall. This 'idle' current should be very low. If it's excessive, suspect some cooked windings in the xfmr.

Well the only problem is, that as I pointed out in a previous post I have accidentally replaced two .05 MFD capacitors with 2 .0047 MFD capacitors because I misread the capacitor code on the outside of the capacitors, which I thought they said 473K on them but then after I installed them in the TV set I looked at the code marker again and saw that it actually said 472K not 473K like I thought it did.
So I have two capacitors in the TV that are outside of the tolerance rating of the original capacitors so I'm afraid to power it up until I get those capacitors replaced with the correct value capacitors which I currently don't have any .047 MFD 630 VDC capacitors in my capacitor stash.

I don't want to order anything yet unless I can make a full order and I can't do that until I know this thing is going to be worth my time ordering the rest of the capacitors I need to finish the job and I don't want to put an order in for just two capacitors because that's a waste.

Does anyone have a couple of .047 MFD 630 VDC film capacitors that they could spare?

[Electronic M]

Originally Posted by vortalexfan

Well the only problem is, that as I pointed out in a previous post I have accidentally replaced two .05 MFD capacitors with 2 .0047 MFD capacitors because I misread the capacitor code on the outside of the capacitors, which I thought they said 473K on them but then after I installed them in the TV set I looked at the code marker again and saw that it actually said 472K not 473K like I thought it did.
So I have two capacitors in the TV that are outside of the tolerance rating of the original capacitors so I'm afraid to power it up until I get those capacitors replaced with the correct value capacitors which I currently don't have any .047 MFD 630 VDC capacitors in my capacitor stash.

I don't want to order anything yet unless I can make a full order and I can't do that until I know this thing is going to be worth my time ordering the rest of the capacitors I need to finish the job and I don't want to put an order in for just two capacitors because that's a waste.

Does anyone have a couple of .047 MFD 630 VDC film capacitors that they could spare?

The test he suggests (pull every tube and power up for a current measurement) will work accurately no matter what capacitance you installed for paper caps...Basically, there will be no tubes to put signal into or take signal out of those caps, there won't even be B+ voltage anywhere...THe only part that should be energized is the power transformer...You could probably glue a pair of leads to a rock, solder that in place of the caps your scared of and not have it do harm or affect the results of the suggested test.

The point here is to verify the expensive/rare power transformer does not have an internal short/current leakage (read that verify the trans ain't ruined). If it don't draw too much current order all the caps when you have the dough, if it draws too much current shelve the set for a few months till you can track down a good transformer or kick it down the road to its next owner.

[vortalexfan]

Originally Posted by Electronic M

The test he suggests (pull every tube and power up for a current measurement) will work accurately no matter what capacitance you installed for paper caps...Basically, there will be no tubes to put signal into or take signal out of those caps, there won't even be B+ voltage anywhere...THe only part that should be energized is the power transformer...You could probably glue a pair of leads to a rock, solder that in place of the caps your scared of and not have it do harm or affect the results of the suggested test.

The point here is to verify the expensive/rare power transformer does not have an internal short/current leakage (read that verify the trans ain't ruined). If it don't draw too much current order all the caps when you have the dough, if it draws too much current shelve the set for a few months till you can track down a good transformer or kick it down the road to its next owner.

OK thanks that's what I wanted to know. I'll proceed with the test then, since I don't actually have to fear ruining the set with the wrong value capacitors in it with this test, that was my main concern.