[Elecraft] P3TXMON question?

[CR]

On 8/21/2015 9:03 PM, Ken Kopp - K0PP wrote:
> Bird accuracy is specified to be ± 5% of meter full scale ... a 100W
> element would be a poor choice to measure a 100W output level.  Take a look
> at any Bird's meter scale.  It's not linear and can be read with the most
> accuracy to the left of center scale.  A 250W element is much better for
> measuring 100W.

I've a few wattmeters myself, of various makes and accuracy -- no Birds 
--but if I want ACCURACY I use 40dB directional couplers with additional 
attenuation into  a spectrum analyzer or a 'scope.  I generally leave a 
scope and counter on line for the two main radios in use, with two 
directional couplers feeding a 2-way hybrid, which lets me monitor 
power, flat-topping and frequency all at once. Still need to get the GPS 
disciplined oscillator running, and as I get my brain back (don't ask) 
I'll get that done.

Note on 'scopes: If all you need one for is setting output safely below 
distortion level, you don't need  $$; the cracked-graticule 15 MHz,  
flea-market, Leader scope I left at the Lowell (MI) ARC station is good 
enough reading across a Cantenna.

Cortland Richmond
KA5S