"Bill Turner" wrote in message
...
On Fri, 3 Jun 2005 15:53:31 -0400, "Fred W4JLE" wrote:

First, I would say that 1.7 to 1 is fine, leave it alone. It is what is
expected.

__________________________________________________ ____________

Fred is correct and you can prove it to your own satisfaction if you
like:

Place a field strength meter nearby, close enough so you can read the
meter, and sweep your transmitter across the band. You will find your
power output is remarkably constant whether the SWR is 1:1 or 1.7:1.

There will be some variation of course, but when you find the bandwidth
where it drops no more than about 90% or so, you can operate confidently
anywhere in that region without worrying about SWR.

Works for me.

--
Bill, W6WRT

Just a quick back-of-the-envelope calculation.

SWR' = 1.7

or SWR" = 1.0

Let's assume worst case; all the reflected power is absorbed in the source.
This is not necesssarily the case, but gives us the least signal strength in
the high SWR case, SWR'.

So then, comparing the two cases, the change in power to the load in db is
10*log(SWR'/SWR").

SWR'/SWR" = 1.7

2.3 db, barely detectable, worst case.

So it's a question of how much reflected power can the rig tolerate as well.

73
H.
NQ5H