[AMPS] SWR Protection

[Steve]

Bill I don't know this for sure but what I have read in the hand books is that when you have a high swr on the line to the antenna the forward
power is reflected back from the load and is added to the forward power at the transmitter. I guess that's how open wire feeders with high swr
on the line and a tuner at the transmitter manage to put a signal into the either In this case the forward power should rise with a rising swr
on the line or at least I think it should. I think what you are referring to is a short at the output of the transmitter, not a high swr on the
line like I am considering but a short at the output of the transmitter is something to consider and protect against. I appreciate your input.

PS I also think that there will forward and reflected power on a piece of coax with a short in it or an open on the coax

73 Steve

Bill Turner wrote:

> On Fri, 01 Dec 2000 22:31:15 +0000, Steve wrote:
>
> >Hi Bill, every time I transmitted into the wrong antenna the forward power on the meter goes higher and the reflected power does the same.
> ____________________________________________________________
>
> Ok, then your meter isn't really measuring power.  It's measuring
> voltage while ASSUMING a fixed resistance of 50 ohms, therefore
> displaying the result as if it were true power.
>
> Your proposed method will be better than nothing, but be aware there
> are various faults in the coax and/or antenna which could cause a
> lowering of the measured voltage together with increased current which
> might also be damaging to the transistors.
>
> The bottom line is, for max protection, measure both voltage and
> current at the output and make the protective circuit trip if either
> one increases beyond the set point.
>
> 73, Bill W7TI


--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com