[JoshK]

Just had an idea, brainstorm if you will.  Would anyone be interested in trading tubes, rather than buying and selling them?  I know there are some of you like myself that are hording many tubes and could probably trade some of my extras in order to gain matches/pairs. 

Just thought it might be an interesting alternative to buying and selling and loosing too much money in the process.  It might also be a nice way to trade the tubes you no longer own gear for for those you are in need of?  I don't know if it would work in the details, but this could be an interesting topic to discuss and maybe try out.

I was thinking that it would go on the honor system and if really needed, you could always get a neutral third party on the forum with a tester to test the tubes in an unlike dispute.

[yo2tup]

i'd be very interested. good idea, i say

[chgolatin2]

Kinda of a cool idea however, you never know how many hours the tubes has been in used or who took care of them properly.  But I guess its a good idea.  So many vendors out ther and cheap tubes going around, I dont really see the need for it but if it works then that would be cool.  Also, you have to be careful with "replica tubes" out there in the market

[jules]

Josh,

a question ... how hard is it to get the measurements needed to match pairs and if one person measures a tube with their [possibly simple] measuring equipment will it be accurate enough for another person to use?

Apart from that, how would it go if we had a "tube library" where all the swap tubes and their specs are listed for easy comparison on AC?

chgolatin,

So, is it possible to gauge age somehow?


jules

 

[Berndt]

I would love to participate.

[ZLS]

After considering the question overnight, the difficulty I forsee is how does a person without a tube tester effectively grade and match the tubes?  Personally all I could state in good faith is, "Two years ago when I bought this matched pair..."  The fact that I or anyone else would be operating in good faith is not re lavant to the quality or remaining life of the tube.

[bolly]

interested, but I'll have to learn my AVO VCM 163 first! 

[JoshK]

Thanks for the comments guys.  I just had envisioned starting a thread first and seeing how it goes.   Some of your concerns are valid and I had thought of that.   The only way to really match tubes is to test them on the same tester, so actually trading the tubes would be neccessary.

I just know myself, that I picked up 'lots' of tubes and a box of 6SN7's and I am sure there are plenty of hoarders out there with loose and single tubes where a swap market might make sense, creating value through trading for matches. 

First, I need to go through my ever growing pile of tubes to see what I have for trading and what I need.  But then maybe I'll try to kick it off in a thread in the TP.  The easiest way to get started is to accurate describe your tubes and test them on your tester.   Then send the tube out to the other party and have them test them against their tube.  This will also give us a community calibration tool.

By george... why don't we send around a working, decent but not expensive tube to each willing participant to gauge calibration of testers...or better yet a few tubes at different 'goodness' and operating points.  I think I have some tubes that can be guinea pigs. Of course, I'd want them back eventually but it wouldn't be the end of all things if they were damaged by USPS or broken by accident.

So we can first start by compiling a database of our measurements of the guinea tubes and the specifics about your tester. 

I first have to fix my tester before I can start or acquire another (which I might anyway). 

[vman71]

Great idea!  Unfortunately, I don't have a tue tester, so I will either have to rely on the information that was given to me when I bought the tubes or my best guestimate based on my use.

[jrebman]

Josh,

Are you talking about testing emission only, or gm too?  There are lots of cheap testers out there that only test emission, which for folks like me, because of their equipment have to pay close attention to triode balance.

-- Jim

[JoshK]

I am thinking of a mutual conductance tester than measures gm.  Excuse my ignorance but what is an emissions tester?  I mean what does it test exactly if not conductance?

[jrebman]

I tend to agree.  While it would be interesting, I just think the logistics could get messy, and the possibility of other things going wrong is too great.  Good idea, but I really can't count myself in for this.

-- Jim

[JoshK]

I can understand the reservations.  I think ideally this would be better for your extras, not your prized NOS rarities.    I'd still like to potentially organize a tube testing tour, so that we as a community can calibrate our testers.  I am thinking some of the cheapies, but working tubes.