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How to keep your profits from going to the“dogs"!

Another w*y RCA heips you

-    imorove your

business

\

Review these important facts about heater-cathode leakage

Did thot TV set come back? Same Symptams —60-cycle hum bars? You diagnosed łhe trouble carrecfly—a leaky tubę .

Here's why a leaky tubę eon cause yau a lat of trouble.

H-K leakage provides a path far 60-cycle current ta Dow from fhe heater ta the cath-ade. If there is no resistance or impedance in the cathade Circuit, this leakage current usuolly causes no difficulty.

CATHOOE

RESISTANCE

When there is resistance in the cathade Circuit, the H-K leakage current develops o 60-cycle voltage across the cathode resis-tor. This voltage moy produce visible ond/ or audible 60-cycle "hum".

H-K leakage in the RF, IF, ar video stages of a TV receiver eon praduce 60-cycle hor-izontol pulling and "hum" bars.

H-K leakage in the sync-seporator tubę ar in the harizontal AFC, oscillator, or output tubes can produce 60-cycle horizontal pulling without "hum" bars.

H    | HIGH*

H-K LEAKAGE -1 ^VAI-UE

RESIST-

H r <= | ^,nce

In detectar, discriminotor, ond AFC stoges, which usuolly hove relatively high volues of resistonce in the cathode Circuit, even a slight omount of H-K leakage current can easily cause visible and/or audible 60-cycle "hum" symptoms.

An H-K short Circuit, or low-resistance leakage, in a series-string tubę, shorf-circuits port of the heater circuit. The resulting higher voltage across the remaining heot-ers moy cause heater burnaut.

H-K leakage in a damper tubę which has its heater grounded may cause the H.O.T. fuse to blow.

RCA tubes help you beat these problems— drasticolly reduce heoter-cathode leakage and shorts through such improvements as precise control af heater coatings to elimi-nate "thin spats"...better heater stem lead arrangements ... new cathode materials and structures. Avoid callbacks caused by tubes that develop H-K leakage problems and keep your profits from "leaking" toa. Remember to always ask your distributor for RCA TUBES!

RADIO CORPORATION OF AMERICA

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Electron Tubę Dlvlslon    Marrlson, N. J.

October, 1959