At 02:24 PM 1/21/00 -0800, you wrote:
>Hi Steve:
>
>I have modified a number of commercial conduction cooled 6 meter amps
>(similar to 4CX250) for use on 6 meters. The 4CX250 will work great in the
>SB-200 - however you need to solve the following problems:
>
>1. Regulated screen voltage. G3SEK has a nice web site for a regulator board
>that provides some protection of the tube.
>
>2. Bias voltage (easy to get).
>
>3. Air must be blown through an air system socket, so you need to be
>creative on where the air comes from and how it is divided between the two
>sockets.
>
>Except for these things, it is a piece of cake. And that is why ham radio
>is fun.
>
>73, Colin K7FM
>
Hello Colin,
Thank you very much for your reply.
Yes, I have already found my way to G3SEK web site and his Tetrode Board,
it is of interest. It is also nice that it is available in kit form from
DEM. I have
also his QEX article.
The thing I found interesting is that the SB-200 has the 572B tubes mounted
horizontally. I have yet to take the amplifier aprt for the modification. I
am studying
it all at present, I need to decide where and how to mount the tubes,
verticle or
horizontal and what to make the chimneys out of (buy ?, only if verticle)
how to
mount a blower.
Have you actually done a SB-200 to 6 with these tetrodes Colin ?
/s/ Steve, N2CKH
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