[Amps] Gettering - ETAL

[Mike Tubby]

On 07/11/2011 17:16, richard courtway wrote:
> Lots of information around concerning the real need to HI-Pot  /
> Getter glass tubes - especially concerning the popular 3-500 series.
>
> But not so much concerning the same need for Ceramic / External Anode
> tubes.  How come ??  Do they actually need the same attention - if
> not - why not ??
>
> Thanky,  de N7RC
>

Interesting question... many external anode tubes are "self gettering" 
in-so-much-as the gettering substance is painted on to the cathode and 
the process of running the tube (heater on) is sufficient to getter the 
tube.

I have a 8877 amp on 6m which is used about once a year - the IARU 
Region 1 6m Contest. Every time I start to pack for the contest (we 
travel down to IN79JX - a rare grid) I put the RF deck on for 12 hours 
or so with no HT (just heater and blower) to getter the tube again, 
before throwing 3800V on it and tuning up on the field... the amp is 12+ 
years old now and still going strong!

Mike G8TIC