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. I
plan to calculate the swr and shut down the amp with a high swr but the amp
will be shut down first if the cpu sees a high output which could
be from overdriving the amp or high swr and then calculate the swr from the
last known good values from the detector and then figure out what
caused it to trip. Most transistors fail quickly from too high a voltage on the
collector or drain and a little slower from too high a current
through the device. Like Marv says most swr detectors are really voltage
dividers with a current sense to determine forward and reverse power
voltages
Bill Turner wrote:
> On Fri, 01 Dec 2000 20:08:14 +0000, Steve wrote:
>
> >quickest way to shut
> >down the amp is to monitor the forward power output and trigger a shut down
> >when it goes above a certain value which is what I plan to do
> ____________________________________________________________
>
> Not a good idea. For example, consider an open connection in the
> coax. Voltage goes up, current goes to zero, output power goes to
> zero (which is what you're monitoring) and your amp continues merrily
> along.
>
> Back to the drawing board.
>
> 73, Bill W7TI
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