[hpsdr] On the air with Alex + Question...

[Bruce Beford]

> Are you in a position where you can measure the voltage on the wires
> between Mercury and Penny?  Or on the IDC (ribbon cable connector) via
> which they get from Alex to Mercury?  The jumper is to get the signals
> to the ADC channels on Penny so they can be measured.  According to the
> Alex manual,power is: P = V * V / .09, where 3 v = 100W (100 = 3*3/.09).
> So 20w * .09 = 1.34v.
> You should see approx 1.34v on the forward power wire/pin (pin 2 on
> Mercury on the Molex connector.

I am running the same version of PowerSDR, v1.19.3.4 baseSVN 3444 (W5WC -
8/15/11). I -do- see fwd power while in TUN mode, but not the amount I
expect. hint: You need to select Fwd power reading in the meter drop-down,
while you are actively in TUN mode.

At 14.5 W out (confirmed), PowerSDR reads about 107 mW. Pin 2 of the Molex
on Mercury (which is connected properly to Penelope) measures 1.154 V at
this output level. That works out to (1.154*1.154)/.09= 14.8W. close enough.

So, I have the expected FWD power level measurement back to the boards, but
PowerSDR reads low. Before I got Alex, PowerSDR read the output power of
Penelope directly (and correctly). I wonder if the power reading routine has
been properly modified to ignore the input that comes directly from the
output of Penelope?

Bruce, N1RX



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