[hpsdr] Penelope Input and Output Voltages and Waveforms

[Rick ve3mm]

Hello

Duane W5PNM asked for assistance on Teamspeak last night in diagnosing a
suspected problem with his Penelope. He was looking for information on the
input and output voltages at Penelope's output device (OPA2874 Op Amp).

Here are some measurements on my Penelope.

Setup:

Software: K5SO PWSDR 1.19.3.5 diversity20
Frequency 7.010 Mhz.
Power Output measured at 500 mW into 50 ohm load

Voltage measurement at JP2 (Input to T1) 295mV RMS
Voltage measurement at 50 ohm load 5.10V RMS

Measurements were taken with an Agilent Oscilloscope MSO-X 2024A.

I have uploaded a screenshot of the scope at Hamsdr.com in my personal files
section.

http://www.hamsdr.com/PersonalDirectory.aspx?did=44

As is usual in most experiments, one thing leads to something
unexpected......

The input waveform shows a definite 122 Mhz ripple.  I am not sure if it
really there ....is it an artifact a poor scope connection or is it leakage
from the clock connection between my two mercury cards (used for
synchronization for diversity reception). More investigation is needed.

73

Rick ve3mm
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