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Marconi
Posted on Wednesday, September 25, 2002 - 11:37 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Can anyone give me the specifications on RG83/U?

Marconi
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Funtimebob
Posted on Wednesday, September 25, 2002 - 5:48 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

http://home.swipnet.se/27mhz/rg.html
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Marconi
Posted on Thursday, September 26, 2002 - 7:19 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks Bob. Now I have a real question about this line.

The line is noted to be 35-37 ohms with a VF of .66.
Why would Avanti use a 6' section of this line to match their Astro Plane antenna when installed as an Astro Beam?

How does this line impedance, 35 ohms, work into a tuning or matching harness in this case? Does this mean that the driven element, by itself without matching, is showing about 35 ohms with the parasitic elements in place on the boom?

Is this process, matching the line by raising the impedance at the input end of the harness to about 50 ohms in order to improve the match? I know this is a simplified explanation, but is it close?

On the other hand would 75 ohm line be necessary if the load impedance was closer to 75 ohms?

Marconi

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