[Mstuf]

Hello Newbie Here - Not versed much on the world of Tubes.
I just bought an EMC 213 Tube Tester and a Box of Tubes at a Garage Sale and found this site. It was too cheap to pass up for a Gadget Curious Guy.
I downloaded the Manual and Tube Chart but have several things I dont understand.

1. In the Tube Chart - there is often more that one entry with different settings for the same number tube - why is that ?

2. Instructions say to test for Short first.

Example -
Tube 12BE6 E 3 1-5-7 22
Tube 12BE6 E 3 5-6-7 55 OK over Diode

I understand the settings etc.

The same tube on both settings lights the neon light on short test on 4.
Per Instructions I do not flip switches 1 5 7 or 5 6 7.
BUT Both Settings when Quality checked shows the tubes as Good.

I have no knowledge of weather the tubes were Supposed to be good or not. I also have no knowledge of weather the tester is supposed to be functioning fine or not. The Person at the Garage sale said "never messed with it because I have no idea of how to use it".

Some of the Other tubes in the box that I have had time to mess with show the same scenario with short test showing short but tubes testing OK.

Can Tubes that indicate a short still test OK ??
If shorted should they just be discarded ?
If YES - should they be recycled ? Unsure whats inside of them (Mercury etc ) ?

3. Does a Darkened area inside the tube glass always indicate a bad tube or does it just happen because of heat and the Tube can still be good ?


Its been fun and fascinating cleaning up the tester and figuring it out. I remember the 5 cent tester machines at the Variety when I was a kid. I often see old tubes for little or nothing at Sales but had no reason to pick them up. Any Tips appreciated about Tubes or the Use of my Machine appreciated. I think I'm using it correctly - Hoping to figure out if all is right with the tester so I have a reason to pick them up when I see them. Dont tell the wife. LOL

Thanks

Some days its just not worth chewing through the restraints

[tab10672]

I am not familiar with your tester but the ones i have will sometimes show a short on certain settings but that setting/switch position is usually shown in parentheses at the end of the list to let you know it will show short even if the tube is good, try to find the operation manual for testing instructions.

Some tubes have more than one section so you have to test each section individually.

Todd

[Mstuf]

Thanks Todd  -- Yes I downloaded the Manual and instructions.
Per my Example  
Main Switch Settings were E and 3
Filament Selector Switch Numbers were   1-5-7
Shunt was 22  

The manual says to test for short by moving the 12 Switches one at a time from K to P Position EXCEPT the Ones noted as Filament Selector Switches.   You then watch for the test light to come on that indicates SHORT.

My 12BE6  Tube lights the test light on Switch Number 4  - that supposedly indicates SHORT.   BUT when I test for Quality  - the same tube indicates  GOOD.  

So my question  --  Is the tester functioning correctly  ?  because it indicates Short but tube tests good.
Shouldn't a tube with a short test Bad ??     Can a Tube with a short correctly test GOOD  ?

Sorry if my first post was hard to understand  -- I see the Board Software compressed my Lines from the Tube Chart making them hard to understand.

Thanks Again

PS  - Question 3  
3. Does a Brownish Darkened area inside the tube glass always indicate a bad tube or does it just happen because of heat and the Tube can still be good ?

[Eliot Ness]

4.  Unless the tube chart indicates otherwise, it is normal for the neon lamp to glow when only one of the slide switches is pressed to "P" position. This simply indicates filament or heater continuity.

It is not worded very clearly, but what it means is that (unless noted otherwise on the chart) ONE of the switches should show a short because it is the other filament pin.  In the case of the 12BE6 pin 3 and 4 are the filaments:

http://frank.pocnet.net/sheets/093/6/6BE6.pdf

So since pin 3 is already selected as the filament, pin 4 will indicate a short since it is the other filament pin. 

The dark area you see is probably the tube getter:

https://www.tube-town.net/info/doc/dark-getter.html

Finally, if your tester is from the mid-60's it is going on 50+ years old.  That means any capacitors in your tester should probably be changed.

[Paul Philco322]

I have seen some nasty black inside looking things that fire up well, then decnt looking tubes that are shot. Eliot Ness is on the ball. Like those links. Tube in and of themselves are fascinating things.

Paul

[codefox1]

Of course a short in a multi grid tube could also show good for emission or conductance, or whatever, and some tubes were just so screwed up in pin designation that footnotes, sometimes just as screwed up, were needed in tester documentation, which as we all know was not always all that well documented.

As always, a "known good" substitute is he best bet.