[Amps] Coleman lantern chimneys for 3CX1200A7/Z7 and 3-500Z

[gdaught6 at stanford.edu]

Bros wrote:

> While at Alpha/Power I learned how easy it is to make the
> silicon rubber chimneys used in Alpha amps--the only real
> problem is finding a decent source for the material in
> small quantities.

McMaster Carr:  12"x12" at very reasonable prices.

> Think I will measure my 1200s and see what diameter and
> height of chimney they require and the next time I go to town
> I will purchase one to play with.

Remember that the 3-500 is a glass bottle, where we want lots of air 
flow external to the tube envelope.  The 3cx1200 tubes have the dense 
accordion pleated finned cooling structure, and the cooling airflow 
should go THROUGH the anode cooler, and little or none AROUND it.  

Just because the ceramic tubes might fit into a chimney doesn't make 
it a good chimney for them.

Have I said that clearly enough, or is it too confusing?

73,

George T. Daughters, K6GT