[Lowfer] "WE" running very well still...

Thu, 01 Aug 2002 10:02:57 -0400

Mike,

I did a little refiguring of your setup last night. If you have only 14.5v 
Vcc on the final the reflected load from the loop should be only about 22 
ohms in order to pull 1w of power from the supply. If the loop has a 200ft 
perimeter it will have an Rac of about 1.3 ohms if the ground is damp. The 
transformation of 1.3 to 22 ohms requires only a 4 to 1 ratio for the 
transformer. Be sure that you have at least 100uh (unloaded) on the primary 
or you will have to use an 8 to 2 ratio. Sorry to mislead you. The turns 
ratio changes ~ to the square of the Vcc and I have never run with less than 
24v (which I strongly recommend for maximum transistor efficiency).

You really need to get that current sensor calibrated! The current in these 
loops tells the whole story once the size is set. Should be ~.9A with your 
parameters. No need to monitor anything else except the input power. Once 
you get familiar with the rig set your goal on using a lower AC resistance 
conductor like RG-8 which will increase your current to ~1.4A. That's 3.8db 
more signal.

Happy looping!
Bill

>From: "WE0H" <[email protected]>
>Reply-To: [email protected]
>To: <[email protected]>
>Subject: [Lowfer] "WE" running very well still...
>Date: Wed, 31 Jul 2002 23:48:08 -0500
>
>My beacon is still running stone cold after an hour of running QRSS-30. I
>know that I can get the antenna match better, and that will be tomorrow.
>Reception reports are very welcome. I'll get my card design done soon and
>get them out to those that sent me reception reports.
>73's,
>Mike>WE0H
>http://www.we0h.us/lf.html
>185.303kc QRSS-30/CW@15wpm
>ID is "WE"
>
>
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