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

[vortalexfan]

Originally Posted by Kevin Kuehn

200-300 watts would be too much for your set. I wasn't really serious about the 3 way. Like OC suggested just try different wattage bulbs starting with a lower wattage. A lower wattage bulb will have higher resistance than a higher wattage, which is why it will drop more voltage and provide a softer start. But if it's too low it also won't allow the TV to get enough voltage.

I also have a variac, but its currently not wired up, it needs a box, an outlet and a power cord. Anyone have instructions for wiring up a variac?

Pictures of the variac in question posted below.

[Kevin Kuehn]

Originally Posted by vortalexfan

I also have a variac, but its currently not wired up, it needs a box, an outlet and a power cord. Anyone have instructions for wiring up a variac?

Pictures of the variac in question posted below.

The directions for wiring are printed right on the back, no?

Here's a pretty good tutorial on how the dim bulb tester works.

https://www.youtube.com/watch?v=zhQEP-Y_OUU

[vortalexfan]

Originally Posted by Kevin Kuehn

The directions for wiring are printed right on the back, no?

Yes, but I don't know whether or not a regular duplex style outlet would work with this variac setup or whether I would need to use just a single outlet for this setup, and I don't know whether or not this particular variac would support grounded wiring (grounded cord and grounded outlet), and how would I go about marking the voltage calibrations on the box for the knob once I got it wired up and installed in a box so I know what voltage I'm on when turning the knob.

[vortalexfan]

Originally Posted by Kevin Kuehn

Here's a pretty good tutorial on how the dim bulb tester works.

https://www.youtube.com/watch?v=zhQEP-Y_OUU

I already have a general idea of how a dimbulb tester works, I just wanted some instructions on how to get my variac going so I could use it in the future, because I've never owned or used a variac before let alone wire one up from scratch before so that's why a little help would be nice in getting me started on wiring up my variac and getting running properly.

[Electronic M]

Single or double outlet don't matter...my factory made variac has a single outlet, but I plug a 3 way splitter in sometimes. It is a wise idea to put a circuit breaker on the input so if you plug a short into it it don't fry.

A good way to calibrate it once you have a box and knob with pointer is to plug a 40- 60w bulb in with a volt meter connected to the output. Every 10V make a line and label the output voltage every 5v make a dot. Best calibration would be with the input voltage at 120v or 125v. If you know you get say 50v at a knob position with an input of 120v you can take that ratio and mathematically determine the output if the line input voltage is something else.

A while ago I read the president got rid of that stupid law that was phasing out incandescent bulbs...We should see higher wattage incandescent bulbs return to store shelves.

[Kevin Kuehn]

Originally Posted by Electronic M

A while ago I read the president got rid of that stupid law that was phasing out incandescent bulbs...We should see higher wattage incandescent bulbs return to store shelves.

Didn't know that had happened. Sweet!

[vortalexfan]

Originally Posted by Electronic M

Single or double outlet don't matter...my factory made variac has a single outlet, but I plug a 3 way splitter in sometimes. It is a wise idea to put a circuit breaker on the input so if you plug a short into it it don't fry.

A good way to calibrate it once you have a box and knob with pointer is to plug a 40- 60w bulb in with a volt meter connected to the output. Every 10V make a line and label the output voltage every 5v make a dot. Best calibration would be with the input voltage at 120v or 125v. If you know you get say 50v at a knob position with an input of 120v you can take that ratio and mathematically determine the output if the line input voltage is something else.

A while ago I read the president got rid of that stupid law that was phasing out incandescent bulbs...We should see higher wattage incandescent bulbs return to store shelves.

Thanks I'll give that a try. I'll definitely see if I can get my dim bulb tester and my variac wired up.

[Electronic M]

Originally Posted by vortalexfan

Thanks I'll give that a try. I'll definitely see if I can get my dim bulb tester and my variac wired up.

If you have an isolation transformer and some voltage and current meters you could probably build it all into one all purpose tube equipment power box...

[vortalexfan]

Originally Posted by Electronic M

If you have an isolation transformer and some voltage and current meters you could probably build it all into one all purpose tube equipment power box...

unfortunately I don't have any voltmeters or current meters and I don't have any isolation transformers either, and I don't know where I would get those things.

[kvflyer]

This rather inexpensive item solves a lot of the questions about current, voltage, wattage etc.

[kvflyer]

But the item above is not an isolation transformer.

[Electronic M]

If you have a pair of the same model appliance you don't mind scaping that draws 100W or more you can make your own isolation transformer out of a pair of step-down or step-up transformers.

Let's assume a 120V primary and that there is only one secondary (or only one secondary that uses a significant amount of power which will be the only secondary used). To make a bench isolation transformer out of 2 identical power transformers wire a power cord onto the primary of the first transformer, and a power outlet onto the primary of the other transformer, and lastly, connect the secondary of the first transformer to the secondary of the second transformer.

Do you shop thrift stores often? If so keep an eye out for those Uninterruptable Power Supplies used with computers. They look like shoebox-sized power strips. If you can find 2 of the same model they would be perfect. The secondaries are low voltage and beefy (use the secondary with thick wire). Those should be able to isolate a radio and most TVs easily.

I usually look for purpose-built isolation transformers at antique radio/ham swap meets rather than make them.

Here is another dirty trick based on the same principle. If you ever encounter a radio where the AC primary of the transformer has opened and you know the heater winding is 6.3V you can take a similar sized transformer with a 6.3V heater winding and connect it to the heater winding of the damaged transformer to power the set.

[Kevin Kuehn]

Originally Posted by Electronic M

Here is another dirty trick based on the same principle. If you ever encounter a radio where the AC primary of the transformer has opened and you know the heater winding is 6.3V you can take a similar sized transformer with a 6.3V heater winding and connect it to the heater winding of the damaged transformer to power the set.

I'm not sure if all radio transformers would have that 6.3v filament winding of heavy enough gauge to support the total VA of the radio passing though it.

[dtvmcdonald]

Its easy to find big fat toroidal transformers on ebay or Amazon. Many have multiple
115 volt windings that can be used as an isolation transformer or to make a step up or down 115-230 volt transformer. Some have lower voltage windings that can be wired in for small steps up or down and still have, unlike a Variac, isolation.

[vortalexfan]

Originally Posted by kvflyer

This rather inexpensive item solves a lot of the questions about current, voltage, wattage etc.

that's what I have and have been using, what I and Electronic M was talking about was an actual gauge that you had to physically wire into the box of the vairac and isolation transformer so you could monitor the voltage and current draw of the electronic device being brought up on the variac.