[Elecraft] Calibrating the P3 Station Monitor?

[Don Wilhelm]

Peter,

Realistic instrument errors are up to 20% - check the ARRL Product reviews.
It just seems your Alpha meter is off in one direction and the TX 
MONitor is off in the other direction.

See if you can borrow an LP100 wattmeter which has been calibrated by 
N3LP to NIST tracable standards.  That will provide you with an up to 5% 
error.  Larry is reluctant to specify the error any closer than 5%.

In this age of digital displays, we have a tendency to believe that the 
display is accurate down to the last displayed digit.  More often than 
not, that is not true.

73,
Don W3FPR

On 7/19/2018 5:33 PM, Peter Dougherty wrote:
> Hi all,
> I recently installed a TX MON to my P3, and the readings are seemingly far off
> compared to two other meters. The 1.8-54 Mhz/2kW sensor was placed where my
> existing Alpha 4510 meter was connected (after the amp and low-pass filter,
> before the tuner), so I was expecting readings that were more-or-less close.
> However the TX MON is reading far below both the Alpha meter it's replacing and
> the power indicated on my Palstar HF-Auto tuner.
> 
> Here are some sample readings, all of which are using the default 500ms
> TXMonMenu/SensorCal setting, running into a Cantenna resistive dummy load,
> keying down with 27 WPM dits
>