6DJ8 alternates?

[whitelabrat]

Hi all! This is a bit off topic with regards to audio, but tube related.

I keep hearing from folks that it's good to have an oscilloscope for DIY adventures. I found two old boat anchors dirt cheap. A EICO 460 and a Tektronics 531. Probably nothing in comparison to more modern scopes, but I've got a better chance of fixing them myself. The EICO is real simple and it seems well maintained. The Tek on the other hand has some real tired tubes in it. Nevermind all the selenium rectifiers, that I'll replace hopefully sooner than later. My real dilemma are all the 6DJ8 (ECC88) tubes. Geez, this thing is packed with them! At least 10 I guess.

Any suitable alternates out there? 6N23P's? 6N1P's won't do. Attach a chain and toss the scope overboard?

The wiring is all point-to-point so it may be possible to use things with different pinouts.

I could always turn it into an amplifier right?

[SY]

What's wrong with ordinary 6DJ8/ECC88? Lots of sources. JJ has a 6922, exactly the same thing. It's like $10.

[Allen Wright]

In my experience, fixing up an old tube scope is a nightmare, and only for the genuinely crazy or those who want to do it as a labour of love.

I suggest pulling all those possibly Telefunken or Bugle Boy 6DJ8's, selling them on ebay for $50 each to freaks in Japan, and buying a used but much more modern solid state scope.

A couple of months ago I got a HP182C scope in PERFECT condition for circa $180 of ebay.

IMO, test equipment is for use in making your audio work, not for killing your time. Unless you have a huge amount of time and want a HUGE challenge!

Regards, Allen

[Geek]

Originally posted by whitelabrat
The Tek on the other hand has some real tired tubes in it. Nevermind all the selenium rectifiers, that I'll replace hopefully sooner than later. My real dilemma are all the 6DJ8 (ECC88) tubes. Geez, this thing is packed with them! At least 10 I guess.

Is that one of those great scopes that had 100MHz BW when everyone else was still struggling to break 2MHz?

[thevoice]

I have a HP scope with what sounds like a similar tube complement, about 10 Telefunken ECC88's. I managed to pick up about 20 replacement tubes on Ebay for $2.50 each. They are made by god-knows-who, branded Lewis and Kaufman and I have no idea how they would be for audio, they should be fine for a scope though.

Keep your eyes open, there are deals to be had.

[whitelabrat]

Oh dang. This one uses 6BQ7's instead of 6DJ8's. Excellent! 6BQ7's are cheap!

This scope is a 15Mhz I believe. That is pretty good for a late 1950's scope I guess. It also has a very cool blue phosphor! It's in very good condition too. I just can't junk it!

Any questions about the sanity of my sanity in trying to do this is completely valid!

I did pull about four good Telefunken 12AT7's. A RCA 12AT7 blackplate blew a triode to my disappointment.

[tubelab.com]

I had a 531 about 25 years ago. Makes an excellent room heater!
If you give up and decide to part it out the power transformer can be used for a good sized amp.

[whitelabrat]

It does get nice and warm. I measured almost 300watts being drawn. I figure I'd replace the bad tubes, use it as a learning tool and then salvage the enormous power transformer when I'm done. I've already got quite a few tubes for it (12BY7's, 6AU5, 12AX7, 12AU7, 12AT7, 6AU6, etc), so why not have some fun with them?

Anyone try 6BQ7's for audio application before? I suspect they aren't too far off from the ECC88's if they're being used as an alternate in the scope.

[richwalters]

Originally posted by tubelab.com
I had a 531 about 25 years ago. Makes an excellent room heater!

My early days in defense electronics I often used an HP spectrum analyser, it came in several stackable parts (think it was 855B ?) was so large and the Watkins-Johnson backward wave oscillator had a magnet so powerful one couldn't get a screw driver off it.
packed with tubes right through, any of this "real" electronic stuff still around ?

rich

[Jim McShane]

Originally posted by SY
What's wrong with ordinary 6DJ8/ECC88? Lots of sources. JJ has a 6922, exactly the same thing. It's like $10.

Exactly! Or the EH 6922 - either would give fine service in the scope.