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Hi:<br><br>
I've been trying to calibrate my new Pennylane card HPSDR per the
instructions on Page 12 of the Penelope Manual.<br>
(<a href="http://openhpsdr.ogr/wiki/images/4/4c/Penelope_manual_v_1-2.pdf" eudora="autourl">
http://openhpsdr.ogr/wiki/images/4/4c/Penelope_manual_v_1-2.pdf</a>)<br>
<br>
I have just installed the Pennylane card in my HPSDR Pandora which has
Magister and Mercury all powered from the LPU.<br>
I installed the 17-Nov-2011 version of PowerSDR1.16 from W5WC (I prefer
its look to the "skin" of PowerSDR1.19) and have<br>
no problems in receiving with Mercury. Firmware versions are 18 for
Magister, 29 for Mercury and 13 for Pennylane. I am using<br>
Winows XP SP3 on an Asus based PC.<br><br>
I have connected a 50-ohm dummy load to the Penelope output BNC. I
have my scope connected across the load resistor so<br>
I can measure the output voltage and its frequency and look at its
waveform. I do not have a microphone connected as yet.<br>
The "Drive" level is set at 100. Everything seems to perform as
expected except for the output power adjustment. <br><br>
A problem occurs when I try to run the calibration routine in the
"PA Settings" Tab as recommended on Page 12 of the<br>
referenced manual. The initial "Gain By Band" settings are all
set to 49.0 dB. When I click on "Calibrate", Pennylane<br>
starts stepping thru increasing <u>amplitude</u> signal values at 160
meters until at the 4th step the signal begins to overdrive<br>
the output of Pennylane and the signal on the scope shows clipping. After
a couple of more steps, the routine stops with<br>
an "Invalid Gain Found" message. The clipping level is just
under 20 volts peak-to-peak (0.5 watts). The amplitude of the<br>
output first step of the calibration measured 10v p-p on the scope, the
second 15v p-p, the third 16v p-p and the 4th and<br>
following steps are heavily clipped at 18v p-p. The TX Meter "Fwd
Pwr" read successively 251, 408, 624, 628......mW. <br><br>
After trying various settings, I found that if I crank the
"Drive" down to 4, the calibration runs without bombing. In
this case<br>
the amplitude of the output remains constant as the frequency is stepped
to each band in turn. However, after the calibration,<br>
the "Gain By Band [dB]" values are not changed from their
initial settings as I expected they would be.<br><br>
Since Pennylane was checked out at IQLabs, I assume I have not set
something up right but I can't figure out what it is.<br>
Or does Pennylane not work the way Penelope does?<br><br>
Can someone explain just what is being calibrating and how it is done.
Apparently Pennylane is feeding different input signal <br>
levels into its input and is reading the output so as to set the system
gain on each band to get the same output at each rf <br>
frequency. Also, what is the "Advanced Calibration Technique"
that is selected by checking the box in the "PA Settings"
Tab?<br><br>
I have found that I can do the calibration manually. For each band, I set
the "Gain By Band [dB]" to 49.0 and slowly crank it down<br>
until the "Fwd Pwr" as read on the TX meter reads 500mW. This
is with the "Drive" level set back to 100. This appears to
work<br>
properly and gives me a consistent 0.5 watt output on each band.<br><br>
However, if I hold the output at 500mW for too long, I hear a
"poof" from Pandora and everything goes dead! All the red
lights<br>
go out and the program stops. If I turn my power supply off and back on
again, things seem to recover. I suspect maybe a fuse<br>
blowing because of excessive current drain but the total Pandora current
drain including the fan only measures 1.670 amps. LPU<br>
has 2 amp fuses in both its 12 and 5-volt outputs.<br><br>
I have no experience with the type resettable fuse used in LPU. Do they
make a noise when they blow? Are they fast acting or<br>
slow acting? They are 2-amp fuses (unless I got them mixed up) with only
1.670 amps thru them. What sort of accuracy may be<br>
expected for their blowing current? Maybe I should measure the supply
current on my scope and see if there are any high<br>
transient currents. Anyone's experience on these matters would be most
helpful.<br><br>
Thanks for any information or any ideas.<br>
<br>
73,<br>
Bob Mahrenholz<br>
K4QQK<br><br>
<br><br>
<br><br>
<br><br>
<br>
<br><br>
<br>
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