Dumont tube brand ??

[kagliostro]

I got a pair of Dumont 6SJ7 (metal) tubes

as far as I can know Dumont didn't produced tubes, I think they where a reseller

someone knows something about Dumont ? The tubes they marketed, where generally good tubes ??

Thanks

K

[vibrolax]

Actually, Dumont did produce some tube types.  Supposedly, they were the inventors of the magic eye tube.  They also produced cathode ray tubes.

http://en.wikipedia.org/wiki/DuMont_Laboratories

Before Tektronix and Hewlett-Packard dominated high-performance test equipment, Dumont made some pretty elaborate oscilloscopes.

I have used a number of Dumont-labeled tubes over the years, though I never tried to figure out who actually made them.  They always seemed to work fine.

Jon

[sluckey]

I remember the name Dumont from my early years in radio/tv shops. They had a line of receiving tubes and replacement CRTs (picture tubes). Don't know if they actually manufactured them. They were really frowned upon, especially the CRTs.

Dumont also made some cheap oscilloscopes that were exact copies of Tektronix scopes (such as the famous Tek 545 tube scope). I always wondered why Tektronix allowed that! Dumont scopes always had a dim trace that could never quite be focused properly. The timebase module was tough to calibrate and keep calibrated and they always had triggering stability problems too. In other words, they were a piece of shit!

In case you can't tell, my opinion of anything Dumont is very low.
 

[kagliostro]

Thanks for the answers


Franco

[PRR]

DuMont was a great company pre-WWII. Well before TV, they pioneered service-bench oscilloscopes and a few other bits of test-gear. Also some enormous CRTs used for classroom training of techs for WWII. None of it was real high-end, but much early radar and fancy-radio was developed and serviced on DuMont 'scopes.

They lost their way in the 1950s, fooling around with TV and a TV network which sank; but had strong brand recognition, and gradually moved into distributing mostly-bought parts under their own name.

They may or may not have made your metal 6SJ7. The first few years of metal tubes were chaotic. Big promise and short deliveries. DuMont might have tooled-up to make metal tubes to fill the demand, or they may have bought them from Harrison or Owensboro (RCA and KenRad/GE factories).

A tube fanatic might know, but who cares?

[kagliostro]

Thanks PRR




Franco

[HotBluePlates]

... they may have bought them from Harrison or Owensboro (RCA and KenRad/GE factories).

A tube fanatic might know, but who cares?

I'd bet money on the DuMont tube being a re-brand to go in their equipment. Add Sylvania to the list of probable actual manufacturers.

Given a picture of the tube and all markings, someone would be able to tell for sure. At the end of the day, a metal 6SJ7 doesn't fetch very-different prices for different-manufacturer, so it's not worth figuring out except to satisfy curiosity.

[PRR]

> enormous CRTs used for classroom training

[kagliostro]

so it's not worth figuring out except to satisfy curiosity.

I agree

---

enormous CRTs used for classroom training

Cool

Franco

[PRR]

> enormous CRTs used for classroom training

Apparently (as we've heard from some old-school techs here) there were many Large Scale classroom aids.

A radio chassis big enough to live in.
A slide-rule you can read from across the room. (My brother got the one at my school.)
A micrometer big enough to measure shoes.
A soldering iron taller than a sailor.
And that DuMont classroom 'scope.

Not shown here, but mentioned by someone, and a picture found: a multimeter as big as a man.

[Willabe]

> enormous CRTs used for classroom training

Apparently (as we've heard from some old-school techs here) there were many Large Scale classroom aids.

A radio chassis big enough to live in.
A slide-rule you can read from across the room. (My brother got the one at my school.)
A micrometer big enough to measure shoes.
A soldering iron taller than a sailor.
And that DuMont classroom 'scope.

Not shown here, but mentioned by someone, and a picture found: a multimeter as big as a man.

Well, why not!   

~ If ~ I only had a house big enough and had enough $$  to house them all!

[sluckey]

Probably this pissum 6 from Keesler...

[eleventeen]

Yeah, I had to do a cap job on on my old Deluxe so I invited 2 friends over to help move the caps into place while I torched them in.





 

[kagliostro]

Hey Eleventeen

Is this a your idea ?

I like it VERY MUCH !



Franco

[eleventeen]

Yes! Good use for small pieces of scrap wood, maybe you can get small scraps for free. The wood you are looking at is redwood which I doubt you have over there, but it is very soft. I would suspect you have some type of very soft wood. (Redwood is used because it resists rot and can be used outside)

[kagliostro]

I showed your idea to some friends in an italian forum

Now you have many followers 

you've had a really good idea 

Thanks

Franco

[eleventeen]

Thank God for Italians!! 

[kagliostro]

[PRR]

Recap, even bigger.

[sluckey]

Not again? It's the same pic. Mr. dumont sure thinks more highly of his stuff than the people that had to work with it, or service it, or sell and provide a warranty.

[PRR]

Not again? It's the same pic....

Different ad copy. But if this is a problem I will delete it.

[HotBluePlates]

Don't make a mountain out of a molehill?


 

[sluckey]

Not a problem. I noticed that the ad had changed but wanted to point out it's the exact same pic. While I was at it, I figured I'd restate my experience/opinion of dumont.