"Patrick" wrote in message
...
Hi All,

I'm about to build a 4CX1500B amplifier for 2m.

Most, if not all, descriptions are blowing air into the enclosure on the
base side of the tube and the air goes through the socket and finaly
through the anode chimney.
For several reasons i would like to blow into the anode enclosure directly
onto the anode, the air would then go out through the anode chimney. Only
a small part of the air would cool the base of the tube through small
holes in the anode/cathode separation.

Is that a stupid idea ? Is there any reason not doing so ?

73, Patrick

Patrick -

I would suggest that you look at the 6M DXpedition Amplifier designed by
Chris, G3WOS.
Great photographs and commentary on desire to stay portable, cooling
requirements and
overall compartment design of the amplifier. It may give you a few ideas.
He used a Eimac 3CX1500A7 (8877) tube.
http://www.gare.co.uk/amplifier/

For your tetrode 4CX1500B amplifier, I would strongly suggest using Ian
White's (G3SEK) control board:
http://www.ifwtech.co.uk/g3sek/board.../tetrode-1.htm

Ian also has his 1997 QEX article available for reading on tetrode designs:
http://www.ifwtech.co.uk/g3sek/board.../tetrode-3.htm

w9gb