[Top] [All Lists]

Re: [Amps] SB-220 update and gettering

Subject: Re: [Amps] SB-220 update and gettering
From: Joe <>
Date: Sun, 27 Nov 2016 08:12:22 -0600
List-post: <">>
Now I have been getting conflicting answers on initially bringing up a pair of these 3-500Z's from a long rest. (almost 25 years) Some say power them up with filament voltage only first and very slowly using a variac. Te others say NEVER run them at non small window spec'd voltages.

so what is it?

The Original Rolling Ball Clock
Idle Tyme
On 11/27/2016 12:25 AM, John Lyles wrote:
It is my understanding that the 3-500Z has a filament heated getter that is always active when the tube is on. Also, if it has a special coated anode with gettering ability, then that is active. If the anode is one of the reactive metals like tantalum, then it will also getter the tube. From what I am hearing, the new graphite anodes have coatings that will help, but I am not familiar with those.

So the answer is yes, there is always getter action on power tubes, not just the flash getter that works during manufacture.


n 11/26/16 10:29 PM, wrote:
Message: 3
Date: Sat, 26 Nov 2016 18:15:48 -0600
From: Lee <>
Subject: Re: [Amps] SB-220 update and gettering
Message-ID: <>
Content-Type: text/plain; charset=windows-1252; format=flowed


OK I understand what you are saying.  But, how does a graphite 3-500Z
tube get gettered after sitting around?  You say heating the anode to
glow does not getter the tube.  I realize the graphite tube was gettered
when manufactured.  Since glass seals leak, can a graphite 3-500Z be
gettered again down the road or was it a one time deal at the factory?

Lee, w0vt

Amps mailing list

Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>