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Re: [Amps] SWR & OPEN WIRE

To: "Mr. and Mrs. Magoo" <magoo@isp.ca>
Subject: Re: [Amps] SWR & OPEN WIRE
From: Roger <sub1@rogerhalstead.com>
Date: Fri, 24 Apr 2009 00:38:51 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>

Mr. and Mrs. Magoo wrote:
> Shortly after I was licensed in 1959 I built an 813 rig from the Handbook.
> My antenna was a 65 ft flat top fed with 450 ohm open wire.  I had a very
> crude antenna coupler and my "output indicator" was a fluoresecent tube
> taped to the open wire.  I tuned the plate tank into the coupler and the
> coupler into the antenna until the tube lit up.  The plate on the 813 glowed
> cherry red key down....but I was too dumb to realize that it was probably
> caused by driving the poor thing into a severe mismatch.
>
> SWR?  What SWR?  It worked....I got out and worked all sorts of DX.  The 813
> survived, nothing arced over and I was in ham heaven.  Moreover, the
> neighbours never complained about TVI, telephone interference etc.
>
> We have become too focused on SWR, IMHO.  Unless you run a BIG amp and are
> worried about heating/arcing etc an "SWR reading" well above 3+:1 won't have
> much effect as long as the amp can find a spot where it is "comfortable" and
> you can tune for peak output/minimum plate current.
>   
Just get one of the new solid state KWs.  You gain a new appreciation 
for keeping the SWR LOW.<:-))  3:1?  How about finding the amp kicks out 
at 1.3:1, or rolls back the output by 300 or 400 watts.  That SS amp is 
much happier at FULL output into a 1:1 than at 600 watts with a 1.3 or 
1.4:1. Over current, over voltage, or reflected power can kick it off 
the air with just a cycle or two at those levels. That's where good ALC 
helps out when you get excited in a pile up. <:-))

73

Roger (K8RI)
> Bill, VE3NH
>
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