Thread: Observations
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Old September 30th 08, 05:27 PM posted to rec.radio.amateur.antenna
JB[_3_] JB[_3_] is offline
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First recorded activity by RadioBanter: Apr 2008
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Default Observations


"Sal M. Onella" wrote in message
...

"Dave Platt" wrote in message
news
In article ,
Sal M. Onella wrote:


snip

I have two HF radios, (Kenwood TS-120, TS-870) and I often observe the
forward power climbing as I manually tune and reduce the reflected

power.
At first glance, this would seem to indicate the rig had previously
throttled back its output in response to the consequences of a

mismatch.


snip
So, it's entirely possible that Kenwood uses a transmit-power
throttleback algorithm which is sensitive to the output SWR, rather
than to the absolute level of reflected power seen by the finals.


Could be. I have not analyzed the innards of the beast, but the -870
detects and displays SWR at all power levels -- so it _knows_. That's

one
of the bar-graph metering choices and if there's more than a watt or two
out, it will report SWR, good or bad.

Kenwood typically looks at forward, reflected current (or voltage) and
adjusts ALC voltage in response to a rise in either. In my TS130, I adjust
tuner into the ballpark, advance carrier, and fine tune for minimum ALC
reading.