There IS a reason to be fanatical about a 1:1 SWR, although it doesn't
apply to an amp like the KPA1500.
If you are running a tube amplifier that requires tuning, and the tuner
always provides the identical load, you can tune the amplifier once,
record the dial settings, and quickly reset the amplifier tuning "by the
numbers" when you change bands.
But even a small change in load impedance might require manual touch-up
of the amp tuning. So it is nice to be able to preset the tuner exactly.
Of course, you lucky guys with KPA1500s don't have to worry about that!
73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
On 30 Nov 2018 00:57, Don Wilhelm wrote:
Andy and all,
The KAT500 and KAT1500 tuner band segments are divided into frequency
band segments - 25kHz wide on the lower bands and 50kHz wide on the
upper bands if I recall correctly, so an 8kHz shift will not be
significant unless the frequency shift moves the tuning into the
adjacent segment.
There is also a limit to how far the firmware will go to reducing SWR.
In the interest of minimizing tuning time (and relay wear and tear). If
the match is less than 1.3:1 or so, tuning will be declared adequate and
will be stopped.
Since the typical driving transceiver can tolerate an SWR of at least
2:1 without power foldback or damage, setting that 1.3:1 limit is
reasonable - unless you are a 'purest' and mentally can only tolerate a
1:1 SWR (big grin).
73,
Don W3FPR
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