Check this out

[greenmeanh1]

I found a working tube tester. After spraying some switch contacts and a look over i tested all my stock of used 6L6's that have been laying around for years. Ended up with three good pairs and about a dozen which are garbage. Quality parts in this thing.The only thing wrong with it is the paper scroller is a bit wonky but fixable. Im stoked!!

[deci belle]

Yay!! Tube testers are cool!! But…

Don't throw away your bad tubes yet!!

[greenmeanh1]

Yay!! Tube testers are cool!! But…

Don't throw away your bad tubes yet!!

Well, I threw them out already. No good reason to keep them. I did a secondary test on the tubes in my Peavey Encore to confirm they were bad which they were. Cost me a few fuses and there were some sparks inside a few of the tubes. Most were distorted with no power. The ones that showed a short on the tester i did not try in the Peavey Encore for oblivious reasons. Put a good set in after i was done to make sure the Peavey still works OK.
Next i am going to go through all my 12ax7/12at7's of which i have about 50 of them. Also, have a pile of EL34 and 84's to go through. I only use about 5 types of tubes in all my gear. 12ax7 12at7 6L6 EL84 El34 and i have one amp that uses 6V6's.
All the other tubes i have laying around are 25 year old Ampeg Gemini 12 tubes 7199 etc,, none of which i can use. I do have an old Ampeg V4B but it uses different tubes.

[deci belle]

haha!! Ya, I've thrown away tubes when I should have too!!

[g1]

If you are using it, then I suppose you have the operator manual/schematics.
But in case you want a pdf copy, you can get it here:
http://pacifictv.ca/schematics/stark966opmanual.pdf

[Richard]

I managed to take out 2 amps with the same bad tube! I thought that the first one (SF Princeton) just was getting old and that that's why the resistor between the first and second nodes of the PS filter caps blew. That and running 6L6's. Put the tubes in my SRRI and immediately took out a 470 Ohm screen resistor (R62 or R63). Live and learn.

[DRH1958]

Well, I threw them out already. No good reason to keep them.

Actually there is a good reason to save them. Mark each with the type of defect it has and save it. Then months, or years down the road, put the defective ones back in and see if the tester will still find the problem. Some go out of calibration and fail to diagnose certain types of bad ones. These will provide a test to make sure it will still find bad ones. Or use them if you get a different one to test it for good operation.

Good resource g1, here's another: http://bama.edebris.com/manuals/ This has about as many in one place as I have found.

[greenmeanh1]

What i did find was a PDF scroll sheet online from Pacific Radio. Easier than using the paper scroll which in my unit is not working to well. The PDF could be used to print out a new scroll sheet as well if needed.
I have to say i'm pretty happy with the unit thus far. I have been trying good sets off the tester in a pair of Fender Concerts and they sound great. I was afraid of just sticking tubes in good amps without knowing,, that is why i used the Peavey Encore as a sacrificial lamb.
I tested about 25 12ax7's today. Half were borderline,, oddly the best ones were china tubes. I have only tried a few in the peavey preamp section thus far but the borderline tubes sound a bit farty compared to the high testing china tubes which sound way cleaner. I have noticed that most of the bad tubes, except 4 i tried, will work as reverb tubes.
On to some EL84's now or as some would say 6ca7's

[mozz]

EL84 is 6BQ5.

[Jazz P Bass]

That is a misprint I would hope.
"On to some EL84's now or as some would say 6ca7's"

EL34 is the same type as the 6CA7.

[DRH1958]

Also, have you calibrated it yet? They are pretty useless unless the resistors and caps are in spec. These usually have been sitting a while and need calibration. I'm wondering why you have so many bad or borderline tubes. Preamp tubes can last 50 years or more.

[greenmeanh1]

I run a music studio in Toronto with four rehearsal rooms to maintain. Been doing this for 30 years come February 2016 so i have accumulated a pile of amps etc over that time. I go through a fair number of preamp tubes mostly due to tubes going microphonic in Fender amps. The Mesa Boogie's seem to eat power tubes.
Also, yes i meant EL34's in my last post,, although i have a bunch of EL84's to test as well.
I will see about getting it set up with a cal. Last cal appears to be done in 2003 by the previous owner who was the CBC. There is a CBC ID plate on the unit as well.

[Enzo]

If you are new to tube testers, they are better at telling you some tube is BAD. They are not very good at telling you a tube is GOOD. You can only trust them so far.

[DRH1958]

[ATTACH=CONFIG]36955[/ATTACH]
I run a music studio in Toronto with four rehearsal rooms to maintain. Been doing this for 30 years come February 2016 so i have accumulated a pile of amps etc over that time. I go through a fair number of preamp tubes mostly due to tubes going microphonic in Fender amps. The Mesa Boogie's seem to eat power tubes.
Also, yes i meant EL34's in my last post,, although i have a bunch of EL84's to test as well.
I will see about getting it set up with a cal. Last cal appears to be done in 2003 by the previous owner who was the CBC. There is a CBC ID plate on the unit as well.

Glad to see you are on top of things and have been involved with equipment. So many people go "Great, I've got a tube tester. Now I can tell if i have good or bad tubes" without knowing the first thing about the process and knowing what they can and can't do. Enzo is right, they are not the end-all and be-all of knowing about tubes. Good to know this was calibrated in 2003. Chances are it's still pretty close. Some have never been calibrated.

[g1]

Or some have been calibrated to show all tubes borderline . That was a good way to sell tubes back in the day, as no one plugged their new replacements in to test them (thus realizing new tubes were borderline too!).
But you say it was calibrated by the previous owner and was a CBC item, so obviously was not used to sell tubes.

If you are going to use it a lot, get socket extenders. You do not ever want to replace a worn out socket in a unit like that, it's a wiring nightmare in there.