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

[vortalexfan]

Originally Posted by Electronic M

I honestly have probably never hit the 800 part order threshold, but I do try to make my orders as few and big as I can to maximize price break and shipping ecconomy (read that minimize cost per item in my stock).

It isn't necessary to hit any of the volume price breaks... however planning buying to do as much of that as practical for you saves you money in the long run.

Not to sound rude but complaining about spending $8 shipping to get a single 10 cents part here in a week and prefering to spend $1 on a local part that should cost 10 cents seems like a logically conflicted argument. So a cheaper alternative was suggested.

When it comes to anything new I am as cheap as they come, and proud of it!

Well the problem is that with digikey and Mouser, in order to get free shipping you have to make a minimum $80 order, and none of my orders ever reach that minimum.

Plus when I get old radios, record players or TVs to fix up, I never know what value of capacitors are going to be in it until I open it up or look up the service manual, and seeing as half the time when I get an old radio or record player from someone I don't know what the model is until it's in my hands.

So it's kind of hard to make a bulk order of capacitors when half the time I don't even know what I'm going to need until I get the radio, record player or tv.

So to me just ordering the capacitors once I know what I need makes more sense, seeing as no two radio, record player or TV circuits are the same when it comes to what parts they will need it's kind of hard to know what parts to order in bulk and what not to order in bulk.

[Electronic M]

Originally Posted by vortalexfan

Well the problem is that with digikey and Mouser, in order to get free shipping you have to make a minimum $80 order, and none of my orders ever reach that minimum.

Plus when I get old radios, record players or TVs to fix up, I never know what value of capacitors are going to be in it until I open it up or look up the service manual, and seeing as half the time when I get an old radio or record player from someone I don't know what the model is until it's in my hands.

So it's kind of hard to make a bulk order of capacitors when half the time I don't even know what I'm going to need until I get the radio, record player or tv.

So to me just ordering the capacitors once I know what I need makes more sense, seeing as no two radio, record player or TV circuits are the same when it comes to what parts they will need it's kind of hard to know what parts to order in bulk and what not to order in bulk.

Ordering exactly what you would need in advance of purchase and no more is basically impossible, but there are good ways of estimating approximate future need...in the earliest days of my restoration (when I was 10-15 years old) I my folks would only take me to places I could buy parts 1-4 times a year...I made and never discarded shopping lists and when I started pre-stocking parts to be ready to fix 80 percent of sets immediately (even if randomly given to me that day) I estimated what I need to stock in bulk by tallying up how many of each part I bought in a year's time and or how much I bought since I started and the hand full of values I needed most were the first to be bulk stocked.

Things less commonly needed like resistors you can if you keep your eyes open at swapmeets periodically find large assortments of for cheap....near the end of my no money period I found a couple of lots like that which I'm only now deleting to the point where I'm considering buying an assortment of new parts to replace (NOS carbon comp resistors sometimes are just as troublesome as the originals).

[vortalexfan]

Originally Posted by Electronic M

Ordering exactly what you would need in advance of purchase and no more is basically impossible, but there are good ways of estimating approximate future need...in the earliest days of my restoration (when I was 10-15 years old) I my folks would only take me to places I could buy parts 1-4 times a year...I made and never discarded shopping lists and when I started pre-stocking parts to be ready to fix 80 percent of sets immediately (even if randomly given to me that day) I estimated what I need to stock in bulk by tallying up how many of each part I bought in a year's time and or how much I bought since I started and the hand full of values I needed most were the first to be bulk stocked.

Things less commonly needed like resistors you can if you keep your eyes open at swapmeets periodically find large assortments of for cheap....near the end of my no money period I found a couple of lots like that which I'm only now deleting to the point where I'm considering buying an assortment of new parts to replace (NOS carbon comp resistors sometimes are just as troublesome as the originals).

Yes, but the problem is that I don't have radio swap meets near me and I don't have any local electronics parts retailers near me anymore (radio shack is gone and there aren't any Fry's Electronics Stores near me either.)
The only way I can get capacitors and resistors for my repair projects is through online outlets like Antique Electronics Supply, Mouser, Digikey, Parts Express, etc. and like I said none of the radios, or record players I've worked on so far in my 15 years of working on vintage electronics have had the same values of capacitors in them (there wasn't any "standard" values in the radios or record players that I could go by to just guess what values of capacitors I was going to need in the future to order well in advance for future projects).

To illustrate what I'm talking about:
about 10 years ago worked on an old Delco radio from 1937 and it had capacitors like .01 MFD, .02 MFD, .03 MFD, .1 MFD, etc, and I unfortunately had an issue with the radio where I ended up having to remove the brand new capacitors I put into the radio and scrap the radio out because the speaker cone got damaged beyond repair and so I had those capacitors from that old Delco radio sitting in my parts stash for over 8 years before I ended up finding another radio that used those values so that I could finally use some of those capacitors that had been sitting in my capacitor stash that whole time.

So now you know why it is that I don't like to order things in advance or try to "stock up" on random capacitor values because more than likely with the way things have been for me, most of them will just sit in my stash for several years before finally getting used, which to me is a waste of money to sink $100+ into bulk ordering random capacitor values when most of them will more than likely never be used or will sit for several years before finally being used.

[Electronic M]

.01 and .1 are 2 of the most commonly used values and the ones I stock in the highest quantity (not uncommon for me to replace 100 of those in a year)....you must have barely been working on anything or working on a lot of oddball stuff to not have used them for 8 years!

The others while not as high usage ain't exactly oddballs either.

With the number of threads you post I figured you'd be working on more stuff than that tale implies.

[vortalexfan]

Originally Posted by Electronic M

.01 and .1 are 2 of the most commonly used values and the ones I stock in the highest quantity (not uncommon for me to replace 100 of those in a year)....you must have barely been working on anything or working on a lot of oddball stuff to not have used them for 8 years!

The others while not as high usage ain't exactly oddballs either.

With the number of threads you post I figured you'd be working on more stuff than that tale implies.

Well a lot of my messages are asking about stuff that I see at flea markets and antique malls and seeing if I should bother getting it or not, which some of that stuff I've passed on, because you guys said the price was too much for what it was.

Also I've had many radio projects over the years that I just had to scrap out because they had too many issues with them that wasn't worth my time fixing.

I've worked on probably 40 radios and record players over the course of 15 years and I've only had about 20 of them that were successful repairs that I had either kept or sold, the rest were junked out for various reasons including bad wiring, bad speaker, or I just couldn't get the radio to receive any stations no matter how many tubes or IF cans I replaced.

So no, it isn't surprising that I had sat on those capacitors for 8 years before using them, and that's because I only bought or was given maybe 2 radios a year for most of that time. It's only been within the past 6 years that I've been able to get more than 2 radios a year.

[static1701]

I order from "just radios" they have a $20 min, but on average it cost that much just for the electrolytic's. They ship it with a packing list that has the part number printer on the caps listed next to the value so it makes it easy to identify the bag of parts. I have been trying to "stock up" on the ones I use the most.

[vortalexfan]

OK, so a little update, I replaced EVERY capacitor there was to replace in this TV and the TV is still drawing way too much current somewhere because the wattage draw on the TV powering it up was approaching 400 watts and the rectifier tube was still arcing.

Any ideas of where else I could look?

I know its not the power transformer or the choke as I tested those without the tubes in and the current draw was normal.

Could it be my flyback or something in my high voltage section, if so how do I check?

[Electronic M]

Originally Posted by vortalexfan

OK, so a little update, I replaced EVERY capacitor there was to replace in this TV and the TV is still drawing way too much current somewhere because the wattage draw on the TV powering it up was approaching 400 watts and the rectifier tube was still arcing.

Any ideas of where else I could look?

I know its not the power transformer or the choke as I tested those without the tubes in and the current draw was normal.

Could it be my flyback or something in my high voltage section, if so how do I check?

Unlikely, but pulling the horizontal output tube would be a good way to check....your power consumption should drop well below the rating with the H out pulled.

You probably have a short somewhere down stream of the choke.... such as in the focus coil circuit or one of the loads on the B+ lines.

You only followed a fraction of the short tracing procedure I laid out on a previous page of this thread...you should be better served following that method to the end/extending it to the loads on the line than grabbing chit outa a hat and throwing it at a wall in hopes of something sticking...

[vortalexfan]

Originally Posted by Electronic M

Unlikely, but pulling the horizontal output tube would be a good way to check....your power consumption should drop well below the rating with the H out pulled.

You probably have a short somewhere down stream of the choke.... such as in the focus coil circuit or one of the loads on the B+ lines.

You only followed a fraction of the short tracing procedure I laid out on a previous page of this thread...you should be better served following that method to the end/extending it to the loads on the line than grabbing chit outa a hat and throwing it at a wall in hopes of something sticking...

Actually I figured out what the problem was, I had the filter choke wired up wrong, and fixed it, now the low-voltage issue is fixed, but now there's something going on with the tuner as there is some smoke coming out of it when I power on the the TV and let tubes warm up, it smells like it might be a resistor or something because it has a sort of "old dust" smell similar to the smell you get when you first turn your furnace on for the first time in the fall.

[vortalexfan]

OK new problem now, my power switch now is arcing and sparking out of nowhere, and I have no idea why its doing that.

I took the tuner apart and the only parts in there are a couple of ceramic caps and several resistors of which none of those parts look burnt so I sprayed some contact cleaner in the tuner on the contacts and worked the tuner knob around.

But as for the power switch/volume control and it arcing like it is, I'm not sure why it would be doing that.

Any ideas?

[vortalexfan]

OK so I figured out two of my problems that had cropped up, the issue with the smoking tuner was the tube I was using in my tuner, the 6AG5 tube of the tuner (which I didn't have any of to put into the tuner when I got the TV because that was one of the many tubes that was missing in the TV when I got it) was substituted out for a 6AK5 (which my tube substitution guide told me that was an appropriate substitute for a 6AG5 tube) but apparently the 6AK5 in this situation wasn't an appropriate sub for the 6AG5 as I think it was pulling more current than the tuner circuit could handle because once I swapped out the 6AK5 with a 6CB6 the tuner didn't smoke anymore.

As for the arcing power switch it was the rectifier tube I was using because I was trying some different 5U4 tubes in the TV and apparently the 5U4 tube I had stuck into the TV had some issues with it that only showed up when it was in circuit because when I stuck another 5U4 tube in the circuit the power switch stopped arcing.

but then yet another issue popped up, and it was in the audio circuit, R62, a 390 Ohm 1 watt resistor suddenly started smoking, and I'm not sure why, but I did have a raster on the screen of the TV just before I noticed the smoke from this resistor which I then promptly shut off the TV.

I did measure the 390 Ohm resistor and it measured extremely out of tolerance, it measured .475k Ohms which when I went to measure it in ohms it just measured O. L. on my multimeter.

I don't have any 390 Ohm 1 Watt resistors but I do have a 330 Ohm 1 Watt resistor, would that work, in place of the 390 Ohm resistor?

I did check and the resistor tolerances in the TV are 20% and 330 ohms is within the 20% tolerance of the original part.

[vortalexfan]

I actually did have some 390 Ohm 1 watt resistors in my stash, I replaced the original one with one of the ones I had in my stash and its still wanting to smoke for some reason, and I can't figure out why...

I'm so close to getting this TV going and this one resistor wanting to smoke is keeping me from getting there...

[vortalexfan]

OK so I think I for sure have figured things out this time, I double checked the Vertical and Horizontal Oscillator tubes and the Vertical Oscillator tube was one of the tubes that was missing in this set when I got it, and so I installed a
NOS Sylvania 6SN7GTB tube I had in my tube stash, which without realizing it should of been a 6SN7GT tube, because I didn't realize until just now that the 6SN7GTB tube is NOT the same as a 6SN7GT tube, the heater is Different and a few other differences as well, so I think that if I can get a new 6SN7GT tube installed in place of the 6SN7GTB I had installed in the TV that might fix my problem.

Unfortunately the 6SN7GT tube is over $20 a pop and I don't have that kind of money to throw around right now...

[vortalexfan]

OK so I had pulled the 6BG6 Tube out of the circuit and the current draw definitely fell quite a bit, but only down to about 160 watts which is what this TV is rated at when its running correctly which means something is still drawing excessive current yet in the set, but not sure what, as like I said all of the capacitors are brand new so the capacitors can't be the problem, the power transformer isn't the problem, the filter choke isn't the problem (i had confirmed from looking at the schematic that I had the filter choke wired up wrong which after I rewired it correctly, fixed the arcing problem with the 5U4 Tube).

So as of right now I've basically troubleshot and repaired everything that could of possibly been causing issues with this set.
The only other issues that could be causing problems in this set is the Vertical or Horizontal Output Transformers or the Flyback Transformer.

[old_coot88]

The 6SN7gtb differs only in having controlled heater warmup time, useful in series-string applications. Makes no difference in your application. Any 6SN7 is fine. 'GT' refers only to bulb style. The 'B' is the heater thingy.