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Re: [TenTec] antenna analyzer reading?

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] antenna analyzer reading?
From: Ken Brown <ken.d.brown@hawaiiantel.net>
Reply-to: ken.d.brown@hawaiiantel.net, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sun, 21 Feb 2010 09:09:55 -1000
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
>
> My question : - Is it better to try and achieve the lowest SWR (peferable at 
> the end of the 70 ohm ladder line as this becomes part of the antenna) and 
> then rely on the ATU (as I do) or is my friend correct to go the easy way.
>
>   
>   
Using a combination of ladder line and coax lengths the give impedances 
which can be matched by your ATU will be more convenient, but likely 
more lossy that just using ladder line all the way to a wider impedance 
range capable balanced tuner. The best way, as far a transmit power 
efficiency goes, will be to keep the high SWR on the ladder line, and 
not in the coax. Put the tuner between the ladder line and the coax, and 
keep the SWR on the coax to 1:1 by adjusting the tuner. This will not be 
as convenient, because you will need a tuner you may not own yet, and 
when you get one it will likely not be automatic or it will be fairly 
expensive.

Remember, the most convenient all band load for your transceiver is a 50 
ohm non-inductive resistor. You get a 1:1 SWR on all bands with no 
adjustments needed when you change bands. This setup is a bit 
inefficient in terms of RF field generated versus RF power generated by 
your transmitter. Antennas that are similarly convenient for multiple 
band use are often similarly inefficient.

DE N6KB
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