BoatBanter.com - View Single Post - How to use a simple SWR meter and what it means to your VHF

On 24 Nov 2003 18:09:12 -0800, (Gw) wrote:

Back when we used tubes I remember that the plates would glow red
then white hot depending on a few factors one of which was how the
output pi filter was tuned, For them that don't remember the output pi
filter tuned the output of the plate circuits (usually about 50k) to
the 50 ohms that the coax liked, hopefully the antenna was 50 ohms
also. So the finals were affected a lot by the swr they saw and we
could see it also just by the color of the glow, white meant better
shutdown and retune or just retune without shutting done.

You should hear the effect of SWR on a 4-cavity UHF TV transmitter
klystron running 20KV at 5A of collector current.....Most
exciting...(c;

Of course, it's not as near as exciting if the FOCUS magnet or its
power supply have a problem...and the stray electron beam eats a hole
in the side of the 7' tube.

Makes one want to get more involved in high energy physics......(c;

POWER is our FRIEND....

Larry W4CSC

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