[Lowfer] Where is everyone tonight???

Sun, 28 Jul 2002 01:34:05 -0400

Mike,

Of what use is an SWR meter? If your final is at the base of the loop, where 
it should be, (even at 136k) there is no such thing as an SWR. The input AC 
resistance of the loop (.4 to 2 ohms) is where the power is dissipated and 
the transformer turns ratio can be anything depending on the power you want 
to run. The output impedance of these transmitters is very low, like 1 ohm. 
Lyle is wong on this if he says "50 ohms", unless this is the effect of the 
filter. In my case I have to insert a 60 ohm resistor in series with the 
exciter output and the 70ft, 70 ohm coax to the final box. If I don't do 
this the exciter transistor pair run hot and it's because of the poor match 
to the coax. And I've never had much luck with that output filter of his. 
Very hard to vary the frequency when using one without changing the output 
waveform considerably.

My concept of a 100w final is a stage not that different from my little 
final out in the woods. Maybe a little heat sinking will be needed similar 
to that used on a 100w switching supply. These European 136ers that suggest 
large transmitters for 100w are too used to traditional Ham transmitters.

Bill

>From: "WE0H" <[email protected]>
>Reply-To: [email protected]
>To: <[email protected]>
>Subject: [Lowfer] Where is everyone tonight???
>Date: Sat, 27 Jul 2002 22:22:21 -0500
>
>Is everyone sleeping except for me??? I am building up my LF SWR meter
>tonight, so I'll be up for a bit.
>
>Mike>WE0H
>http://www.we0h.us/lf.html
>185.303kc QRSS-30/CW@15wpm
>ID is "WE"
>
>
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