Shopping carts of 6GH8As’? What is your story?

[Eric H]

In the late 70's we did a lot of repairs on older color sets and we always wound up replacing all the 6GH8's in almost every set.
Towards the end )the end of me working there) the owner was ordering them by the dozen.
They were dirt cheap too, I can't remember if it was 5 for $1 or $1 each but it was cheap, of course we could buy rebuilt color CRT's for $30 back then.

[Chad Hauris]

Originally Posted by drh4683

Im surprized this box of 6GH8's went unopened. I bought this this box of 100 on ebay last year and took a picture when I was the first to break the seal. The box manufactuer has a date stamp of 5-82 on the bottom of the box so these are somewhat "new". With the RCA TV's I've picked up waiting to be serviced, probably half of this box will be gone instantly.

Wow, that's a lot of 6GH8's! The type number font looks like Sylvania...I wonder if RCA had quit making tubes for the most part by that time. I know the 6GH8's I've seen that were OEM in RCA sets were actually made by RCA.

[jr_tech]

Did 5GH8s have a similar problem? Seems like CTC22s and other small RCA color sets were full of them, and were fairly reliable sets.
jr

[leadlike]

Huh, just went through my tube inventory, and yeah, from years of picking, I have amassed over 30 6GH8s, which is far and away the most plentiful of any tube I have.

[drh4683]

Originally Posted by Chad Hauris

Wow, that's a lot of 6GH8's! The type number font looks like Sylvania...I wonder if RCA had quit making tubes for the most part by that time. I know the 6GH8's I've seen that were OEM in RCA sets were actually made by RCA.

You're correct Chad, these are sylvania made tube as the script has the "USA" under the letter, which easiliy identifies the manufacturer as sylvania. Real RCA made tubes would have had the octagon around the tube number. Not sure when they pulled the plug on tube production though. Seems like more lost history in the electronics industry.

[radiotvnut]

I wonder when consumer grade (radio. TV, phonograph, etc.) tube production ended in the USA? In the mid '90's, I remember buying some USA built PhilipsECG tubes for use in TV's; but, they could have been sitting on the dealer's shelf for years. About a year ago, the old man who owned the local parts house said he still had a ton of new 6GH8A's and wanted to know how many I needed. I didn't say much, as he's one that is a little proud of his stuff. He has since passed away and I think his son is running the business. Now might be a good time to see if those tubes are still around.

[Chad Hauris]

I know that some of the last tubes produced in the GE factory in Owensboro, KY. were 6550's I think in around 1992-1994 or so. The company which owns the factory now is called MPD, Inc. making microwave devices but they continued to make glass tubes up until that point. I'm not sure if they made other tubes in the 90's or just the 6550. I worked on a Leslie organ amplifier which was newly made in 1992 and used the MPD 6550 tubes.

They had the "Electronic Tube" script logo just like GE but no GE monogram and the date code was 92. They said something like "Made to GE specs by MPD inc. in Owensboro, KY."

I have seen some PhilipsECG tubes too which likely were from the late 80's, a 6HA5. They said SylvaniaECG with the modern Sylvania logo on the tube for a while and then the very last ones said PhilipsECG but I think they were made in USA in the original Sylvania factory.

[dieseljeep]

Originally Posted by jr_tech

Did 5GH8s have a similar problem? Seems like CTC22s and other small RCA color sets were full of them, and were fairly reliable sets.
jr

I had one of the early model CTC22's. It had a great picture on it. I think I replaced the 5GH8's twice in the three years I owned it.

[kc8adu]

the 5gh8 was just as bad.i remember replacing every last one in some sets just like with the 6gh8.

[maxhifi]

Hmm I'll chime in here - here's what I've always heard quoted from years of reading about tube audio.

RCA - 1976 stopped making consumer tubes, but kept making certain transmitter and industrial tubes until the early 80s. I have some genuine RCA 807s from 1982.

Sylvania/PhilipsECG - 1988 stopped making tubes. Sylvania made tons of tubes for the US government though the 80s, as well as audio power tubes until things shut down. In the early 90s I bought a number of PhilipsECG audio tubes which were either Chinese or Russian, with early 90s date codes, so the name didn't die with the factory. Don't know when it did.

GE - As above, up till 1992 the GE factory was making at least the 6550. I remember ads in the back of Popular Electronics in the early 90s with bulk quantity pricing on about 10 GE tube types, so it must have been more than just the 6550 until almost the end.

Westinghouse - not sure... but I was buying Westinghouse branded tubes new until the early 90s - all were imports and not really made by Westinghouse

This isn't lost history, there's books written on the subject and it's well documented due to the strong interest in tubes from the audio and antique radio communities. I always enjoy reading about the history of the electronics industry in North America.

To connect this back to the original thread, the only device which I have which uses 6GH8's, is my 1990 Dynaco ST-70 reissue. Dynaco explained they used it because the original's 7199 was too expensive by that point. I've been using it for several years without changing the tubes, but I did have to test a whole pile of used ones before I could find a pair which tested good.

[Findm-Keepm]

Anybody have a copy of the Application Note for the 6GH8? RCA promoted the 6GH8 to everybody, and the application note (24 pages, according to my Radiotron Designers Manual) probably had a sampling of RCA-designed circuits for use with the 6GH8's - Audio, Video, Chroma, Pulse, you name it. It's the broad application (and RCA's insistance that it be used in every RCA TV) that brought it into the limelight. 6EA8, 6U8, 6BL8, 6KT8 - everybody used some form of the triode-pentode in their sets.

When I was a kid in my Dad's TV shop., I would be amazed when he would fix a set with a 6GH8 problem, by merely swapping the 6GH8 out with another 6GH8 in the set, never having to replace anything. Not working as a Chroma Oscillator? No problem - swap it with the Bandpass Amp tube (another 6GH8) and watch the magic. You could throw a hundred 6GH8's in a circuit and find that only half would work, but all would test fine on any Hickok, Sencore or B&K tube tester out there. I'm sure it boils down to different electrical characteristics that are never tested - stuff like plate capcitance, inter-electrode capacitance, and the like.

It would be interesting to contrast the 6GH8 with "the most used transistor of 1980 - would it be a 2SC1172B, a 2SC945, or some other Japanese wunderkind?

Cheers,

[bgadow]

20 years ago I met an old, retiring TV repairman. (He had been an Admiral dealer, and was quite a character) Among other things, he sold me a couple caddies full of tubes. Dozens of 6GH8s, and man, did I think I'd got a great deal! But every one of them was used.

Among my current stash of NOS GH8s I try to keep a variety of brands, figuring if one doesn't work another might be closer to what the set wants. I think I have some Hewlett-Packard branded tubes, which are probably RCA or some such, but I figured maybe they demanded the better grades?

[DaveWM]

I picked up some NOS realistic brand (rat shack) 6GH8's at a ham fest for VERY cheap (IIRC guy just gave em to me), anyway very nice looking tubes, gold pins, but I seem to recall them not working well when I tried them in some of my sets.

[ctc17]

I have a huge collection of 65- 72 color sets and hardly ever have problems with 6GH8s. I will say that whenever one is change in the color circuit its a good idea to do a color afc alignment. The tolerance of those tubes is all over the place.

[Blast]

I was 14 in 1970 and knew little to nothing about TV repair. My friend and I used to ride our bicycles back behind TV repair shops and dig through the dumpsters. Over a short period of time I amassed quite a large collection of 6GH8's. They always seemed to test ok in the testers at the drug stores.