On the bench: 1953 Raytheon Vu-Matic 21" TV

[Sandy G]

WTF were they THINKING ?!? Talk about Re-engineering the Wheel.... Sheesh !

[wa2ise]

Originally Posted by Electronic M

Could also grab an isolation 'booster' ....

A 6.3V filament transformer would also work.

[jr_tech]

Originally Posted by Kamakiri

Opened the back and saw a brightener. Wonderful. Removed the brightener and went to test the picture tube. The tube lit up WAY too bright on the tester and showed a dead short...so something either happened when I removed the socket on the picture tube or something's really amiss.

Originally Posted by Kamakiri

This picture tube issue is weird. With a "remove shorts" procedure, the tube tests into the good range, but the H-K leakage pegs the needle. Not sure what type of picture that'll end up giving.....?

Originally Posted by Electronic M

Could also grab an isolation 'booster' and skip the modification.

I wonder if the "brightener" that you removed was *actually* providing isolation of the heater cathode short

jr

[Kamakiri]

Well, I still have it. I always keep a couple around just in case I need to squeeze some life out of a dying tube. But that's a very very interesting question.....WOULD it isolate the short?

Hm.

[Electronic M]

Some "brighteners" were not (just) brighteners. Some only isolated the heater to fix H-K shorts, some only increased the heater voltage, and some did both isolation and heater voltage boosting.

When you see a "brightener" on a CRT it pays to read the label before removal so that you know if it is on there for a good reason....

[Olorin67]

I Think the companies thast made boosters also sold isolation models. I recall seeing ads in old tv repair magazines that advertise models that provide an isolation function, and arnt actually boosters at all.

[Username1]

Cool tuner....

.

[dieseljeep]

Originally Posted by Olorin67

I Think the companies thast made boosters also sold isolation models. I recall seeing ads in old tv repair magazines that advertise models that provide an isolation function, and arnt actually boosters at all.

The more expensive Perma-Power brighteners were designed to be both isolation and boost, series or parallel. IIRC, it had four different configurations. It was twice as long as the cheaper units and had a five pin selector plug, to select boost or no boost, series or parallel. All the instructions were on the unit, to suit the application.
I might have one somewhere in my stash.

[Kamakiri]

This one is an Anchor model SP43 Series & Parallel TV picture brightener. It's set up for a parallel setup.

[dieseljeep]

Originally Posted by Kamakiri

This one is an Anchor model SP43 Series & Parallel TV picture brightener. It's set up for a parallel setup.

Antronic made them as well. If it's an isolation brightener, it would say on the unit.
I would try the separate transformer trick, as suggested by others.

[Zenith26kc20]

It looks like the tuner with the high/low frequency slug tuned system. I have a TrueTone the mice loved (atop the tuner). Strange tuner if it does have it.

[DavGoodlin]

Originally Posted by dieseljeep

Antronic made them as well. If it's an isolation brightener, it would say on the unit.
I would try the separate transformer trick, as suggested by others.

Vid-Aire made one with a plug that selected between series or parallel filament strings, I dont think it isolated.

I had a 1958 Motorola series-heater set with an intermittent H-K short in its 21CBP4. The short made it go washed-out negative with retrace lines.
After I isolated the CRT filament with a perma-power brightner, video just got a bit smeary when it shorted.

[dieseljeep]

Originally Posted by DavGoodlin

Vid-Aire made one with a plug that selected between series or parallel filament strings, I dont think it isolated.

I had a 1958 Motorola series-heater set with an intermittent H-K short in its 21CBP4. The short made it go washed-out negative with retrace lines.
After I isolated the CRT filament with a perma-power brightner, video just got a bit smeary when it shorted.

Several companies made various types of brighteners. IIRC, Workman made a brightener for the early Sony Trinitrons. They also made one called the Super-brightener that boosted the heater voltage to 9 volts. It was used on the RCA 23EP4, that had a different pin-out. The picture looked good, for how long, was anyone's guess.