[Amps] Outgassing tubes.

[Will Matney]

Ian,

Your correct about the differences! I've seen the innards of several types of transmitting tubes though and never seen a true getter like the ones used in receiving tubes. Where are they in them as I've not seen them. Generally you have a pin which connects directly to the getter where they use at the factory to flash it. They used to call these pins out on tube specs as NC or do not use. I imagine you could attach one to one of the elements but I've never seen that.

Best,

Will

*********** REPLY SEPARATOR  ***********

On 10/2/05 at 11:16 PM Ian White G/GM3SEK wrote:

>Will Matney wrote:
>>Even though a vacuum is pulled, when an element gets hot it can release 
>>a small amount of gas, even though they say the material has been 
>>de-gassed. Plus with age, a small amount of atmosphere can seep in, 
>>especially on glass tubes and where the ceramic to steel meets on a 
>>steel tube.
>
>We should be careful to think of these as two totally different kinds of 
>"gassy tube" problems.
>
>The releases of gas from structural materials are big enough to cause an 
>arc when they happen, but are often small enough to be removed by the 
>chemical gettering action (which is built into most transmitting tubes 
>even if you don't know it).
>
>On the other hand, a leak from the atmosphere is only going to continue, 
>and will eventually use up all the gettering capacity.
>
>So the first kind of "gassy tube" problem will often be recoverable, but 
>the other kind won't.
>
>
>-- 
>73 from Ian G/GM3SEK
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps