Tuning up on a dummy load is good practice for a tube rig that needs
"tuning up". For a broadband rig like the Omni's, to tune a long wire
antenna, tuning on the dummy will always produce an out-of-tune condition
as the dummy load is 50 Ohms, while the longwire will be much higher
impedance. I recommend you pre-tune all the frequencies you intend to
use a lot at some time when the band is quiet (daytime for 80m, night
time for 10m, etc.) Pick a quiet part of the band, send a "QRL?" with
low power, and if no one responds, tune up the long wire with the tuner
(still on low power). Make a chart of frequency and the control settings
on the tuner. This will allow you to reset the tuner quickly to a very
close setting. When you make the chart, use some kind of indicator to
show which control is the "critical" one (the one which, if slightly off,
affects the tuning the most). This way, when you go to reset the tuning,
you can tweak this control to bring it in from the preset. In most
instances, you'll probably find the chart gets you very close on the
first try. On some bands you may need to pre-calibrate several
frequencies to cover the parts of the band you want to use. I used to
run an indoor dipole that ran 5:1 SWR, and I worked 20m DXCC in a short
amount of time using that setup. Hope this is useful.
73, Duane AC5AA
On Mon, 8 Mar 1999 21:05:29 EST KF4EIB@aol.com writes:
>
>Greetings group,
>
>Question please:
>When tuning with a dummy load (50 ohm), I get a good swr reading.
>Switch back to longwire antenna and BOY is it way OFF.
>Trying this on novice / tech + portion of 40 meters.
>This is first try with a dummy load... have tuned as fast as possible
>on quite
>freq. before, want to do this right though.
>
>Info...
>
>Ten Tec Omni D
>Ten Tec Antenna Tuner
>MFJ Dummy Load
>MFJ Switch (2 position)
>Long wire antenna
>
>Am I doing something wrong?
>
>Thanks
>
>Gordon kf4eib
>
>--
>FAQ on WWW: http://www.contesting.com/tentecfaq.htm
>Submissions: tentec@contesting.com
>Administrative requests: tentec-REQUEST@contesting.com
>Problems: owner-tentec@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
Duane A. Calvin, AC5AA
Austin, Texas
ac5aa@juno.com -or- ac5aa@earthlink.net
Day: dacalvin@us.ibm.com
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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