12AU7 instead of 6C4

[Dr ZEE]

Hi guys.
I am rebuilding/restoring jackson model 103 tube tester.

It has 6C4 triode tube in it. The one that was there is bad, need to be replaced.
Now, I don't have any 6C4 tubes around but I have bunch of 12AU7 tubes. So my thought was: to add 9pin socket with inside-the-unit switch or to completely replace 7-pin socket with 9-pin socket , rewire and use half of 12AU7 instead.
The question is should this work fine for the tester or am I asking for trouble?
If it is ok, then the other half of the question would be how to do it right, - I mean, what to do with the second triode of the tube - leave open, ground or what?
Or should I just forget about the whole "idea" and just swing over eBay for 6C4s?
thanks in advance for an advice.
/best regards

[ethermion]

A 6C4 costs less than a pack of Camels.

http://www.thetubecenter.com/tubelist7.html

[Dr ZEE]

Originally posted by ethermion
A 6C4 costs less than a pack of Camels.

..and I blame goverment for that.


*****
seriouselly, though
I guess my "idea" does not make any practical sense
but then, I can say the same thing about the fact that I am sitting here spending all that time restoring this rusty metal box to begin with. So common sense is not a common thing in my case

[ethermion]

Your call. Replace the 6C4 for $4, and it will still be a Jackson 103. Sub a 12AU7, and it will become just a rusty metal box. A 6C4 does look like 1/2 a 12AU7, but tube test equipment is funny stuff.

Given that your tester is down, what makes you think the 6C4 is bad?

[Dr ZEE]

Originally posted by ethermion
Your call. Replace the 6C4 for $4, and it will still be a Jackson 103.

not so, unless I spend another three plus nights and days or so with it.
It's easier to build a new one than to restor a such thing in such shape.

Originally posted by ethermion
Sub a 12AU7, and it will become just a rusty metal box.

heh heh, no way. Rust and dirt is my specialty. I take no prisoners .
well, my main idea was actully to add the second socket with switch inside the unit, so it would be an extra option, so it can be 'switched' to use either 6C4 either 12AU7.

Originally posted by ethermion
A 6C4 does look like 1/2 a 12AU7, but tube test equipment is funny stuff.

That's why I asked. The characteristics on paper look the same. I've read somewhere people literally mentioning that 6C4 is basically the same as 12AU7 but single. So I thought somebody here may know first hand that it is or is not ok to use either in the same circuit and expecting the same operation (result).

Originally posted by ethermion
.. what makes you think the 6C4 is bad?

tested on the tester that is not down.


I guess the right way to do it is to get 6C4. Put back together the unit , test some tubes make notes, then add the 12AU7 option, try it test same tubes, make notes, and then conclude whether it was or was not a "good idea".

[Tom Bavis]

Where in NY are you? I'm in the Rochester area. I think I had about fifty 6C4s at last count...

[Dr ZEE]

Tom, I'm diy-ing in Poughkeepsie.
I've got myself into "lot of tubes" bidding already, always trying to grab a bag of stuff
thanks for offer though
/respects

[Dr ZEE]

Tom, I was trying to walk into your 'homepage' site and got punched in the nose by a big guy at the door, asking for my ID and secret pass.
Is it a normal situation for a strange?

[Tom Bavis]

I expect that access problems will be resolved shortly - it's hosted on a friend's PC, and he's made a lot of changes recently.

[Dr ZEE]

Arrgh, I am kind of getting tired of eBay
Tom, I'll try to e-Mail you from your profile eMail link. So this is just a note here in case the eMail does not go through or something.