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Old May 23rd 05, 09:51 PM
Richard Fry
 
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"Richard Clark" wrote
On 23 May 2005 04:49:08 -0700,
wrote:
While measuring the SWR, the needle fluctuates, as the voice is
modulated. Is the "value of SWR" the highest it hits? What's the
convention?


SWR should not vary. It is dependant upon the mismatch of the
transmitter to the load alone. When you get variations of SWR
readings depending upon signal strength, the problem is often an issue
of the meter, and then, secondarily, the transmitter's source
resistance.

_____________

'SWR meters' don't measure SWR directly. They sample the forward and
reflected signals, both of which vary during SSB voice modulation -- even
when the ratio between them (SWR) remains constant.

A variation in forward & reflected readings during SSB modulation is a
normal situation, and not necessarily traceable to the SWR meter, the tx
source Z, a varying antenna system Z, or anything else.

RF