[Elecraft] P3TXMON VSWR Measurement Accuracy

[Robert Nobis]

Wes,

The 1.01 is what the reading indicated. It could easily be higher. Even if it were 1.1:1 it is significantly different that the 2.0:1 reading of eh P3TXMON.

Thanks and 73,


Bob Nobis - N7RJN
n7rjn at nobis.net


> On Sep 8, 2015, at 15:05, Wes (N7WS) <wes at triconet.org> wrote:
> 
> I can't speak to the P3TXMON accuracy. I don't think it's specified anywhere, however, I don't own one and just skimmed the documentation.
> 
> That said, you should be worrying about your "calibrated" VSWR tester.  It's lying to you.  You would pay big bucks to get a precision termination guaranteed to 1.01 (46 dB return loss).
> 
> To have a power dummy load that good would be astounding.
> 
> On 9/8/2015 10:49 AM, Robert Nobis wrote:
>> I am having a VSWR measurement accuracy issue with my P3TXMON.  I have a calibrated VSWR tester that indicates my antenna and feedline VSWR is 1.05:1. When I connect the P3TXMON and transmit, the PS display shows my VSWR is 2.0:1 into my feedline and antenna.
>> 
>> I also tried testing into a dummy load. The VSWR tester shows a VSWR into the dummy load of 1.01:1, whereas the P3TXMON shows a VSWR of 1.29:1.
>> 
>> Power level readings on the P3TXMON are within 5% of measured power levels using a power meter, so the P3TXMON is reasonably accurate measuring the transmitted power.
>> 
>> In reviewing the P3 manual, I do not see any methodology for calibrating the VSWR measurement accuracy for the P3TXMON.
>> 
>> Any suggestions on how to calibrate the P3TXMON for better measurement accuracy?
>> 
>> Thanks and 73,
>> 
>> Bob Nobis - N7RJN
>> n7rjn at nobis.net
>> 
>> 
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to n7rjn at nobis.net
>