[Amps] Re: Amps Digest, Vol 13, Issue 52

[R.Measures]

>At 04:56 PM 1/31/2004, K3vw at aol.com wrote:
>
>>You can use a 3-500Z chimney with the 3CX1200A7, Ameritron does ! Willy K3VW
>
>So, if the Coleman lantern double mantle chimney works with a 4-400A
>and that is the same size as a 3-500Z and if the 3-500Z chimney
>works on the 3CX1200A7 then it sounds like the Coleman
>lantern double mantle chimney should work with a 3CX1200A7.
>
>Can anyone confirm that this is the case?  Don't know the price of
>the Coleman lantern chimney these days but it used to be a
>relatively inexpensive way to get Pyrex glass for your 4-400As.
>
>Since I have a couple of 3CX1200xx tubes (A7 and Z7) but no
>chimneys this would be a good thing to know.   Except for the
>fact that a clear chimney is a real waste with an external anode
>tube.
>
**  John --   A friend who worked in the broadcast industry told me that 
tetrodes with handles (such as the 8281)  emit blue-light from their 
ceramic anode insulator.   This phenomenon is apparently due to electrons 
missing the anode, and impacting the ceramic -- which causes 
flourescence.