Useless I Suppose But Old And Cool

Managed a toob score today but I don't think there's a damn thing I can do with them...

They're all really old 'bulb' types, 4 and 5 pin. I've seen the 4 pin type once before (the size of the pins determines 'keying' usually the two largest being the filament). The 5 pin ones kinda look like an oversized DIN - with a semicircle of 4 pins and an odd 5th opposing them. The envelopes are totally silvered from within so I can't determine the element structure. Worst though is no numbers on them - maybe they're old enough that there were only a few types then? Or just wishful thinking? Also the envelope to base cement seems to have given out - although this in itself doesn't render them useless as electronic devices.

Think these have any (intrinsic) value beyond a shelf display? Of course if I thought anyone had a real use for them I'd take some pics and put them in the trade section at the usual price...

So in this era were there any 'standard' pinouts? Are the 4 pin devices (likely) rectifiers or directly heated triodes? Any guess to filament voltage? I seem to recall an antique book showing 2 x 1.5V cells as an 'A' battery and 22.5V 'B" batteries ... If this is a good ballpark i might be able to sus out the connections and see if they've got any life in them.

Either way, kinda cool just to hold them. I'm guessing somewhere in the 1920's

4 pinners are gonna be DHT's, or rects. (unless they've got a topcap..)

fil voltage was usually 2.5v or 5v.

the only type i have like that is 01A, it was pretty common afaik.
http://www.nj7p.org/Tube4.php?tube=01A

5 pinners are probably tetrodes, but they don't have to be.


You can do a continuity check to find the fil, and go from there...

if you don't have a use or need for them and want to "move" them ...
i know a fellow that will give them a good home .
pm me .

Carefully break off the glass. Use some perspex tube to replace. Small LED to simulate the filament and voila, cool coffee table talking point.

break the glass !!!

in the words of john cleese in "life of brian" in the stoning scene ...
"blasphemer" !!!

"f****g Gondolas"

What's wrong with breaking the glass??? Without knowing what the device is or what you can actually use it for it's nothing more than a silvered lump. For anyone who doesn't know about such things (and there are many), leaving the valve 'as-is' would leave them as clueless as they already are.

"f****g Gondolas"

What's wrong with breaking the glass??? Without knowing what the device is or what you can actually use it for it's nothing more than a silvered lump. For anyone who doesn't know about such things (and there are many), leaving the valve 'as-is' would leave them as clueless as they already are.

For one thing, they probably still work. For another, they are worth more as collector's items if they are intact. There are so few old tubes left that we cannot afford to lose any that are still functional.

Right.

Heavily silvered 4-pin tubes could be 01A's.
If they are 01A's they're worth a fair bit of money, and chances are reasonable that they are still in working condition.

Thoriated tungsten filament tubes can be rejuvenated almost indefinitely, unless the filament is gone. And even if there is no continuity between the filament pins, they have been known to have the pin solder connection fail. So, you can sometimes fix the filament continuity problem by remelting the pin solder.

And, if they're not 01A's, they are still likely to be reasonably valuable.

If CWB doesn't get them, I'm definitely interested.

"well , i certainly wasn't expecting a spanish inquisition ..."

"nobody expects a spanish inquisition ... our three most powerful weapons are ..."

"cardinal , give the rack ... (oh dear) ... a turn !"

Hey CWB,
No problem as far as I'm concerned. You spoke up first.

I was more concerned about the suggestions to smash them.

ohhh ... it wasn't about who gets what ... as long as they go to a good home to get used and/or metted out to others that can use them .

the thread sort of reminded me of that monty python skit .

"cardinal feng , place her in the comfy chair !"

I have several similar tubes. When one burns out sometimes I still want to use it because of it's vintage appearance. I have disassembled them and used a technique that restores it to operation and original appearance without any high tech glassblowing, etc.

I carefully remove the tube from it's base (soak in hot water) and break the seal, then re-work it so I can insert a subminiature tube (I have been using the CK5676 triode.) The gettering silver goes away, of course, but it still looks good. I am looking into re-silvering the insides of the bulb now. That's not difficult, but requires some handling of chemicals that might require caution.

Since it was burnt out in the first place, I don't consider this to be Audion-icide.

When I first saw the post header I thought "Jim's being unusually forthright today...."

quote - "Useless I Suppose But Old And Cool"

If the coat fits........

Can you show us some pictures of those Tubes Jim (your score?).
I just love tubes!

an ohmmeter will help in finding the heater pins. if you really feel up to it you could build a tester circuit to find what pins are which. also have a look on some tube sites to see if you can find anything that looks like yours.

whatever you do, don't break the glass