6BK4 versus 6BK4A

[blue_lateral]

Originally Posted by Kaye-Halbert TV

<snip>

How about a 6BD4? Those are kind of rare, and are electrically the same as a 6BK4. Those seem to be in only 1955-57 color sets. They're neat looking, with a larger base than the 6BK/6EL4s. I wonder if those were even less shielded, or if they just weren't as good-working as the later tubes?

Charles

There is an article on the web somewhere (I cant seem to find at the moment) where experimenters are using 6bk4s as x-ray tubes in homemade x-ray machines. They dont work that well. the guy who wrote the article had a 6bd4, and it worked the best. Apparently the lead shielded 6bk4c is useless in this duty. They run these under completely different conditions than in a television set. I believe the formula was a whole bunch of voltage and a cold cathode.

I think the 6bd4 wont take quite as much current as a 6bk4 or 6bk4c. Since I tend to set the 6bk4 slightly hot, I would prefer a newer tube.

I think that a 6bk4 will only make little (if any) x-radiation unless the set is *broken*. 21.5KV isnt enough HV.

**edit** Found the link. I guess the best x-ray emitter ws a 6en4, not a 6bd4.

http://www.belljar.net/xray.htm

John

[bgadow]

I seem to recall hearing that GE had to recall some sets in the late 60s due to defective tubes that emitted too much radiation. After that they seemed to really be on their toes.

I don't ever recall hearing of an epidemic of cancer among tv repairman, which I will take as a good sign!

I have the service manual for an Admiral color tv with a 21AXP22. It says not to operate the set without the safety glass as there will be xrays emitted from the center of the screen. The safety glass was enough to stop them.

[peverett]

A possible epidemic of cancer for TV repairmen from the 1960s/1970s would be lung cancer. Every one of them that I knew smoked.

[kx250rider]

Originally Posted by peverett

A possible epidemic of cancer for TV repairmen from the 1960s/1970s would be lung cancer. Every one of them that I knew smoked.

I never thought about it much, but you're right! Only one shop owner I know has never smoked; all others do/did.

But off hand, I can only think of a handfull of TV collectors who smoke Most are nonsmokers (and unmarried)

Charles

[daro]

I'm married & I don't drink or smoke.

There were a very few color sets in Australia that used tubes when color TV started in the mid 70's except those that were imported in test trials & those that were brought in by Europein migrents.

The most common was the Dutch made Philips K7 chassis that used a PD500 as a shunt regulator tube & was used inconjunction with the GY501 EHT rectifer, Philips in Australia had at one stage plans on the drawing board to manufacture these sets for the Australian market but in the end opted for the fully solid state K9 chassis instead.

The only tube color TV avaible in this country were sets based on the UK made Decca 30 chassis & these sets used a trippler & only 6 tubes.

[Telecolor 3007]

Isnt't there a electronic tubes catalagoue that explains every tube?