Topics

moderated Vacuum tubes

Harold Fleischer
 

Dear Richard,

 

I photographed some 40+ tubes at the last work session. They were not in boxes, but the manufacturers included RCA, GE, and Sylvania. The newspaper that each individual tube is wrapped in dates from the 1980s-1990s. This is a New Old Stock situation although we cannot guarantee that any of them work. That said anyone buying them knows that they may have to buy more than one to get a good one. If they need it back enough for vintage equipment, they will assume the risk.

 

Until we get done with the inventory and place a valuation on each tube, we will not really know what we have. Once you see the number of boxes of tubes and other components, you will release that this will be a long and tedious process.

 

Your comments give me hope that in the end it will all be worthwhile for SARC and the wider ham community plus maybe others.

 

Sincerely,

 

Harold

 

Harold C. Fleischer, III

AE5AS

ae5as@...

210-497-2532

 

From: Richard Blank <rikblank@...>
Sent: Friday, December 20, 2019 8:45 PM
To: main@saradioclub.groups.io
Cc: Bill Craft <billc851@...>; Harold C Fleischer III <haroldcf@...>; Richard Elder <rcelder@...>; Richard Roudebush <roudie3@...>; rosendo.guzman@...; Lloyd M. Swartz <lswartz@...>; Gary Harmon <gharmon@...>
Subject: Vacuum tubes

 

Since I am probably the only one on this list that actually works in the audiophile arena I'll chime in about tubes valuable to audio aficionados.

 

Assuming USA manufacturing, some of the tubes can be quite valuable today...with European manufacturer tubes possibly bringing more, from mfgs like Mullard, Siemans, GEC, Marconi, Telefunken, etc.

 

12AX7, especially European sourced tubes, even in American boxes, bring pretty serious money today

12AT7, less than the AX, but still desirable

12AU7, still not the AX level

Variants of the above, like the 6201, etc. can be quite valuable

12BH7

7199, scarce, but used in Dynaco amps and some Scott amps, too, no direct replacement exists

 

6BQ5/ 7189. EL84

6V6, beloved by guitar amp users

6L6GC, these bring in good money if American made, the earlier versions,

6L6, 6L6G, GA, GB with lower plate dissipation figures not so much

5881, 5932, 7027  7581

6CA7, EL34

6550

KT-series tubes (European version of the beam power tubes, like the 6550, called "Kinkless Tetrodes", especially KT66, KT88, and KT77.

 

6SN7

6SL7

The 12 volt versions of these are still sought but do not bring in the same cash

6080 and 6AG7 are desirable, but maybe not real valuable

 

Mil-spec heavy duty tube rectifiers, the "potato masher" type.

 

Matching tubes takes more than something like a transconductance tube checker to actually match plate curves and current draws for proper biasing, my TV7-DU isn't one that will do that, but I've always wanted a tube curve tracer...

 

That's about all I can think of for now.

 

Rick

KI5SL

 

 

 

 

On Friday, December 20, 2019, 6:06:56 PM CST, Paul Guido <radioteacher@...> wrote:

 

 

I am out of town and cannot make it. 

 

Tubes can be very valuable.  Tested tubes even more so.  Matched pairs on top of that.

 

Some tubes like large nixies and those sought by audiophiles should be tested and sold on a site like ebay.  I would be happy to test some tubes on my Hickok 752.  I also own a Nixie test unit.

 

Tubes like Tungsol 5881, USA made 6550 and 2A3’s are some of the ones I can name off the top of my head but there are many others.

 

That being said, I would be interested in buying up to four EL34s and four 6V6’s for an amplifier project I have at the market rate the group decides on.

 

We also want to be careful not to flood the market with tubes.

 

Paul   



On Dec 20, 2019, at 3:22 PM, Joe Bruno <jlbruno4433@...> wrote:



This coming up Monday the 23rd of December at 10:00 we will be having another workday, inventory day, to add to our ever-growing items that were donated here recently.  Today we identified some areas that can be streamlined to further assist in this process.  We were hoping that some of the other members of the club would step up to the plate and help with the inputting of the data, obviously not.  We will be moving on though in light of this.

 

Harold has graciously printed out more of the labels we have been using.  This will assist in adding the next batch of items to our inventory.  This inventory has also brought to our attention the need to make sure that, Tubes, if you will, do not fall into the category of trash and end up in the dump.  Some of these items have shown to be very very valuable to the Ham Radio community as well as antique radio collecting/restoring.  The funds generated from this little expedition will pay for at least one radio I think.  That makes it worth it in my book!  One of our biggest goals was to restore the donors’ faith in Ham Radio, from what I have been led to believe we did accomplish this.

 

Radio Fiesta is coming up, and this Monday we will also try to determine what will and what will not be taken to radio fiesta.  This onslaught of tubes has made us take note of the value of these items and what we should do with them to keep the “good ones” in circulation.  Even the bad ones could be inserted into a non-working radio set to just show what was once used to make long distant communications possible.  I guess all they have to do is glow!  At this point in time, I think it would be in our best interest to solicit these tubes to the on-line tube re-sellers to get us more bang for our buck and keep our involvement to a bare minimum.  But an inventory needs to be done to determine what we do have.  Some of the items that we are putting into the system need to be either trashed or recycled.  Most of this should be on a case by case basis to be determined at the time of picking it up and inspecting it.  For all practical purposes once an item is handled a dispensation should be made as to what happens to it.  Handling items numerous times is basically bordering on insanity!  We need to get a little better at this.

 

Any and all who wish to join us this coming up Monday please feel free to do so…

 

 

Joe Bruno

W5AUQ

210-363-9500