On Sat, 17 Oct 1998 22:48:20 -0700 Sam Ferris <ve5sf@sk.sympatico.ca>
writes:
> The TH7 is mounted at 70 feet
>just
>above the top of the tower and the XM240 is about 6 feet above that.
>The
>booms are perpendicular to each other since that is the way that I had
>
>the hygain 402 mounted previously to reduce SWR impacts on 15 metres
>on
>the TH7. Presently the SWR on the XM240 is a little high, bottoming
>out at about 1.55 at 7.050 , 1.8 at 7.000 and 2.0 at 7.125. I set it
>for
>the CW setting in the manual and followed the advice regarding the
>measurement mistakes in the manual posted by others - most helpful.
>In
>comparison to the Hygain 402, it seems that impacts on the TH7 are
>about
>the same, the 15 metre SWR curve looks about the same as before and
>the
>SWR on 10 and 20 metres is now actually lower than with the previous
>40
>metre antenna.
>
>My question is if any others have similar setups with PARALLEL BOOMS,
>and
>if such a change to my system would reduce the impact on the XM240 by
>lowering the SWR. Bottom line is I am not all that anxious to make
>many
>more trips up the tower to spin it.
I have a 40-2cd mounted six feet above a KT-34XA, booms
parallel. The 40 is set for a compromise between cw and
mid-band settings.
Here is the swr curve on 40:
7.0 - 2.4
7.1 - 1.4
7.2 - 2.2
7.3 - 2.8
Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
or call Juno at (800) 654-JUNO [654-5866]
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|