St Regis radio?

[zombie1210]

Curtain burner line cord? Sounds ominous.

[init4fun]

Originally Posted by zombie1210

Curtain burner line cord? Sounds ominous.

Oh yes , it was .

The term "Curtain Burner" comes from the 1930s radios that had a resistance wire built into the line cord to drop the 110 volt AC to the combined (series) 68 volt requirement for the tube's heaters . The 25Z5 and 43 output both have 25 volt heaters , for 50 volts required . Add in the 6 volt requirement of the other three tubes and we add 18 volts to the 50 for 68 volts combined heater requirement . Some sets used a ballast tube (like your set uses) to drop the "extra" 42 volts from the 110 volt line (110 - 68 = 42) and some sets used the resistance wire . The line cord could and did get hot enough dissipating that extra power that fires were started , especially if the line cord was touching something very flammable , like for instance some curtains .

Most folks nowadays eliminate the curtain burner cord and go instead with an AC capacitor to safely (and without heat) drop those extra 42 volts . Since your set uses the ballast tube no such re engineering of the heater circuit will be needed . The one caveat here being that the ballast tube is essentially a light bulb with a tapped element (to provide power for your dial lamps) and is subject to burning out just like any other light bulb is . I would recommend picking up a spare or two of the ballast tube to have on hand since as years go on they ain't getting any easier to find ....

[old_coot88]

..Or just go with a capacitor, with a small value resistor to shunt the dial light. Leave the ballast tube in place for looks.

Ceiling fan speed control caps work great. Gobs of 'em on Amazon.

[init4fun]

Originally Posted by old_coot88

..Or just go with a capacitor, with a small value resistor to shunt the dial light. Leave the ballast tube in place for looks.

Ceiling fan speed control caps work great. Gobs of 'em on Amazon.

Were the ballast tube burnt out and unobtainable sure I'd run an AC capacitor in it's stead and not think twice about altering the circuit , in my opinion running condition trumps original condition with most tube radios . But , since I'll bet replacements for the original ballast tube are still available , and since the ballast tube carries no built in safety hazard by design like the curtain burner cord does , I'd be inclined to leave the circuit as is and stock up on a couple or few spare ballast tubes while they are still somewhat available .

[dieseljeep]

Originally Posted by init4fun

Were the ballast tube burnt out and unobtainable sure I'd run an AC capacitor in it's stead and not think twice about altering the circuit , in my opinion running condition trumps original condition with most tube radios . But , since I'll bet replacements for the original ballast tube are still available , and since the ballast tube carries no built in safety hazard by design like the curtain burner cord does , I'd be inclined to leave the circuit as is and stock up on a couple or few spare ballast tubes while they are still somewhat available .

If the ballast tube is readily available and reasonably priced, then fine. The 165R8 number seems to be a Triad or Hytron number. JFD numbers are different.
When the set was new there was a lot of DC districts, so a resistive dropper had to be used.

[decojoe67]

Originally Posted by zombie1210

Curtain burner line cord? Sounds ominous.

I've had many working "curtain-burner" radios in my many years of collecting and you could literally lay the cord in a pile of dry paper shreds and nothing will happen. Even after long play time it only gets moderately warm. Pure urban legend that it will burn the house down.
It's the same urban legend with the sheet of asbestos on the top of the inside of the radio in which you better put your Hazmat suit on and dispose of it before it sends you to an early grave!

[old_coot88]

Originally Posted by decojoe67

I've had many working "curtain-burner" radios in my many years of collecting and you could literally lay the cord in a pile of dry paper shreds and nothing will happen. Even after long play time it only gets moderately warm. Pure urban legend that it will burn the house down.

That's been my experience with 'em also. The gripe is more on the cheezyness factor than any real hazard.

[decojoe67]

Originally Posted by old_coot88

That's been my experience with 'em also. The gripe is more on the cheezyness factor than any real hazard.

I agree. I like those sets with their original thick cloth cords. Right now I have about 5 that work excellent.

[init4fun]

[dieseljeep]

Originally Posted by old_coot88

That's been my experience with 'em also. The gripe is more on the cheezyness factor than any real hazard.

The real cheap and nasty four tube TRF's were referred to as "Depression radios". They all used the resistive cord droppers and many were sold for around $10 USD. Many of the ones I ran into the cord was damaged one way or another. Most of the time the resistance wire was pulled loose from the plug connection and the plug was replaced.
If the cord was in good condition in later years, many times the resistance wire was rusted open as the wire was some kind of an iron alloy for ballasting action, just like the ballast tubes had.

[dieseljeep]

Originally Posted by decojoe67

I've had many working "curtain-burner" radios in my many years of collecting and you could literally lay the cord in a pile of dry paper shreds and nothing will happen. Even after long play time it only gets moderately warm. Pure urban legend that it will burn the house down.
It's the same urban legend with the sheet of asbestos on the top of the inside of the radio in which you better put your Hazmat suit on and dispose of it before it sends you to an early grave!

If the builder of the product wanted U/L listing, they couldn't get it on a set equipped as such.

[decojoe67]

Originally Posted by dieseljeep

If the builder of the product wanted U/L listing, they couldn't get it on a set equipped as such.

I'm sure of that. It definitely isn't the greatest idea, but the severity of it has been a little exaggerated over the years by collectors.