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Old December 30th 03, 04:35 PM
Gary McAdams
 
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"Charles J. Shaw" wrote in message:
My Kenwood 940 is failing to find a "match" when I engage the auto
tuner.


Charlie,

The first thing to remember is that the 940's tuner, like most built-in
tuners has a fairly limited range. I have been able to tune a tri-bander
on 160, but that does not mean that the tuner was designed to do it.

What I did, whenever the built in tuner would not match, was this:

1. Meter switch to SWR.

2. AUTO/THRU to AUTO position.

3. Press AT.T.

4. Observe SWR readings on meter. You will note that the meter
readings go up and down as the tuner attempts a match.
when SWR hits an acceptable level, i.e., between 2:1 and
1.5:1, disengage tuner by pressing AUTO/THRU button.

5. After tuner stops, re-engage tuner using the AUTO/THRU button,
go to rtty/am/fm. Set power to lowest level. Transmit and check SWR.

6. If the SWR is still OK, then operate. If not try the cycle again.

The software in the 940 is trying to get to the 1:1 SWR level. This
is simply not always possible given the limited matching
capability ofthis tuner and the unlimited types of loads that
could be presented at the antenna. 1.5:1 or even 2:1 is acceptable
to the finals, but not to the AT software routine.

Then there is the real possibility that you might have a problem
in the tuner/radio combination. If you observe the meter while
the tuner is in operation and see no variance in readings, or
hear no activity of the tuner, then there might be a problem.

73, Gary WG7X