[Amps] SB-220 update and gettering

[John Lyles]

This is a good way to run a lot of dissipation with low voltage swing in 
the tube. I have seen this done at one of the National Labs for large RF 
triodes, for same effect. The anode of the tube in the procedure (seen 
in AL80?) is sheet metal with the vertical folds. These respond well as 
the anode is adsorbing free ions. With this procedure, be careful not to 
exceed the dissipation max of the plate of the tube, measured by Ep x 
Ip. I would recommend not going above 2/3 of this, unless you know/trust 
the cooling design of the amplifier well and that the blower and air 
ducting provides the correct mass flow (and back pressure) for full 
dissipation.

73
John
K5PRO

On 11/26/16 4:15 PM, amps-request at contesting.com wrote:
> Message: 3
> Date: Sat, 26 Nov 2016 14:20:50 -0600
> From: Mike Waters <mikewate at gmail.com>
> Cc: "amps at contesting.com" <amps at contesting.com>
> Subject: Re: [Amps] SB-220 update and gettering
> Message-ID:
> 	<CA+FxYXgwYfOUXQLpT1OZp_TdF7aTL0K0GkQ8UeweDLdnHpNEnA at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> Here is an excellent method of gettering tubes, including the 3-500Z.
>
> www.w8ji.com/gettering_tubes_al572b_al80b.htm
>
> There are many other related and useful pages there.
>
> 73, Mike
> www.w0btu.com