Something New - a Brunswick-Radiola BR60

[startgroove]

Good catch! You are correct. I read the number as a UX112 instead of UX120. Yet, I wonder if you could clarify this: "The CX371A was intended for both dc and ac filament 5 volts at 0.5 amps. Which is a higher filament voltage and filament current than the UV199 or UX120. The CX371A is not intended for dry cell use and should not be used." That seems like a contradiction to me. If the 71A will run on AC and (or) DC, why should dry cells not be used? Cheers, Russie

[Governor Flyball]

The CX-371A and UX112 were originally designed for a higher power output to be used in sets employing the UX-201A. Each have a 5 volt filament. The 5 volts design was chosen for 6 volt lead acid battery operation. A series filament rheostat would compensate for battery discharge. The 171A and 201A filaments draw substantially more current. I think this was a matter of providing cheaper less efficient filaments to keep the cost down.

The UV-199 and UX-120 were designed for dry cells (zinc carbon batteries). With a filament voltage of 3 volts it was designed for three 1.5 volt cells with a series rheostat.

The UV-199 uses a thorium impregnated rather than oxide coated filament which yielded a more highly efficient (by mid-twenties standards) emitter which would work well on minimal filament current.

It is most critical not to run the thorium filament tubes too hot or else they will drastically lose emission. Hence the radio filament control is strictly marked not to run the current higher than absolutely necessary. Fortunately, if this happens, so long as the filament still has continuity, it can be rejuvenated.

Anyhow I hope this helps. The mid twenties was an interesting period when all this new technology must have been confusing. I don't think it any different today: just a different technology, that's all!