The below are ham radio test results, NOT engineering test lab results.
(This is what an inquisitive ham does on a Saturday to keep from going out
in the 96 degree/84% humidity to cut grass.)
I have been doing some 'informative' test on my P3 TXMON verses my LP-100A
Vector wattmeter. As we all are aware, the difference of a couple of digits
in the digital readout is typically insignificant.
K3 s/n 8895 and P3 with TXMON installed. K3 connected through my Alpha 9500
(turned off) and my TXMON TX Directional Coupler (DC) to the 9500 RF output,
using a male/male adapter. The DC is connected via a four foot RG-232 coax
to my Bird 500w dummy load.
I first connected the DC and the LP-100A DC in series, at the RF output
connector of the 9500; the K3 was in CW mode and I was keying with my 1916
Blue Racer bug.
I set the K3 to its reading of 100 watts. The 100A read 106.7 watts and SWR
= 1.05:1. The TXMON read 107.0 watts and SWR =1.00:1 {The TXMON is actually
readying the input SWR of the 100A DC}
Then using the TXMON, I set the Pout reading of the K3 to exactly 100 watts.
The 100A read 97 watts.
I then adjusted the K3 for exactly 100 watts on the 100A and using the TXMON
(menu) SCALE CAL, I adjusted the TXMON to 100 watts, resulting in SCALE CAL
(default setting = 500) to 514, closely agreeing with the 100A reading. (The
last digit of the PEP reading continuously changed each time I keyed the
K3).
My personal conclusion is the TXMON agrees with the 100A VERY close and
truthfully adjusting SCALE CAL is not necessary as these are all
uncontrolled test results. The reading of TXMON SWR was close enough to the
100A to be a non-issue.
****************************************************************************
*****************
This is probably of little interest to most, but it is something I always do
just for my own information because I used to operate QRQ at speeds over 100
wpm..
For non-contest keying I use a very old logging program produced by VE6YP,
called YPlog. This program generates CW using Windows internal sound
generation thereby eliminating the 'CW stutter' generated by all Windows
operating PC systems I/O output ports, i.e. Serial and Parallel ports. One
must build a very simple audio detector, driving a simple NPN transistor to
key any radio. I have watched this program on my O'scope, running the 'Quick
Brown Fox' message on a different radio (Icom) at 160 wpm and working
flawless.
My first impression of QRQ keying of the 'improved' firmware for the K3 was
that, to my ear, the K3 was capable of about 95 wpm before the characters
started losing spacing. In testing this a couple of days ago, with the TXMON
installed in my P3, I found out the RF keying waveform from my K3 could
actually go up between 115 and 120 wpm before character spacing began to
wilt! So it was certainly better than my 'old' ears!
8888888888888888888888888888888888888888888888888888888888888888888888888888
88888888888888888
NOTE: This is something I did out of curiosity of my own. I share it with
the reflector just for informational purposes.
My personal opinion of the TXMON is that it's Pout and SWR readings are very
close to the accuracy of an LP-100A, but of course it was not designed to
provide the rest of the excellent capabilities of the LP-100A.
73,
Tom - W4BQF
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