Bob,
Before our minor crisis I think I owed you a .wav file of the receiver. I
set up as follows:
* RF Input: 435.000 from HP 8662A on GSP external reference
* 70 cm Receiver: Also on 10 MHz GPS external reference
* IF out: to SDR-IQ
I demodulated the receiver in CW mode and recorded the wav file using the
SDR-IQ SpectraVue program. I can also send you an RF wav file that you can
use with a new SpectraVue application that they have on their web. The file
is attached.
This screen shot shows the IF output on 10.700 MHz (in green) and the CW
detector shape in orange with the red bar at the top showing the passband.
Will this work for you?
73,
Juan - WA6HTP
All,
We need to take up a collection to buy Stephen a large hero badge. He fixed
the problem and the receiver is now sitting on my bench happily receiving a
signal. The new CAN-Do module that he sent me had a different address than
the old one and the old files were addressing the initialization
instructions to a non-existent device. All we have to do is change the
address field in the initialization files and everything is fine.
Whew! The train of life in back on the tracks!
73 to all,
Juan
Juan:
I talked with Stephen. He is testing your replacement module. He and I
both feel that the likelihood you have a faulty one is low but that
there is no harm in testing this since it does turn out to be the
module, it will prevent you from having to dig into the RX.
Now let us suppose you receive the widget and you cannot get the PLL's
to function.
To what extent does the receiver function now? Does it function well
enough to demonstrate at the annual meeting? If so, why not do non
destructive testing if at all possible and try to get it to run before
we give up completely on it.
Bob
--
AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,
TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
"If you're going to be crazy, you have to get paid for it or
else you're going to be locked up." Hunter S. Thompson
Stephen,
All of the receiver power supplies are functional. My setup has not changed
for a long time. I'm using the same cable harness and power supply as
always. Communications are via a USB port, to a USB-to-serial dongle, to
the CAN232, to the CAN-Do module. This has not changed since day-1.
The CAN-Do Net Controller Software is the same installation I've been
running successfully for months. It appears to run as before. It finds the
CAN232 immediately and then finds your module when I click the Query button.
I set the timing for 200 mSec and select a .can initialization file by
clicking "Playback Log". I can then load the initialization data by
clicking "heartbeat". The data appears to load at the normal rate I'm used
to seeing. After loading the file there are no entries in the error log.
The only odd behavior is that I can always crash the application by
selecting the waterfall log after the data has been initialized. The log
appears to be empty when the application crashes. If I select that log
BEFORE I load the file it comes up with no problem. I've tried loading
different versions of the init file (I have about 10 for various frequencies
and either internal or external reference) and they all result in both PLLs
failing to initialize and a dead receiver.
Yesterday we stepped through the I/O lines one at a time using a DMM and
toggling them using the GUI controls. They all appeared to be OK after some
confusion initially. I can also toggle the power on and off although I'm
bypassing it and feeding the receiver directly from the power supply.
The first LO is drifting around at 598 MHz. The second LO appears to be
putting out RF at 126.4 and 253.2 MHz. These observations are made using a
sniffer cable.
As I said in my earlier email, I'd like to completely rule out a bad CAN-Do
module before tearing into the receiver, especially this close to the
symposium. I'm willing to try anything you suggest, but if you have another
module available I'd like to try that first.
73,
Juan - WA6HTP
Stephen,
Do you have another module that you could send to me? It's starting to look
like I have problems with the original CAN-Do module and the receiver too.
I can understand why the first module doesn't work since I removed and
replaced the power supply components several times while attempting to
troubleshoot the EMI problem. But the receiver is another matter. It's
proven over months of banging around that it is a very robust unit. Neither
PLL is currently working. So either I've got multiple failures on the
receiver board or it's not being properly initialized.
While I wait for your reply I'll be digging back into this and gathering
test data. I'll send that out as soon as I gather it up...
73,
Juan
John, Juan, Bob D., & Bob M.:
I have been preparing for my presentation to the Space Symposium on the
subject of internal module heat sinks. As a concurrent subject, not in my
paper, I have been preparing to discuss the temperatures that modules can
achieve during a solar eclipse of the Eagle satellite. In this vein, things
do get interesting and pretty darned chilly. I am showing the outboard,
deployed solar panels getting down to the -117°C to -125°C! I also show
body-mounted solar panels getting down to -81°C and other body sheet metal
in the -60°C range.
This analytic effort has pretty heavily exercised this new, high speed
computer with some runs taking from 40 to 70 minutes, that is a lot of
number crunching!
The spaceframe temperatures for the start of the analysis was set at +10°C
and modules at +20°C.
For the modules I have analyzed both power off and with modest power
dissipation in some modules. Some modules, with the necessary coatings to be
able to handle 3.5W dissipation (e.eg. the URx in full operation), show a
considerably deeper cooling than those with only the lowest emittance of a
low-power module. Unpowered, or those with very low dissipation, show
temperatures near to zero Celsius after three hours of eclipse while those
of the higher emittance, for higher power operation, can get down to -30° to
-38°C in that same time. This clearly illustrates why I have been pushing,
wherever possible, to keep the module emittance low and to keep the module
thermally decoupled from the spacecraft to the greatest extent possible. It
also reinforces my high degree of upset with our German friends who painted
not only the inside of their P3E modules black, but did me a favor by
painting the outside black as well, failing to follow my instructions. The
P3E situation will have to be dealt with as another issue.
In eclipse, modules with low emittance and modest power dissipation show
temperatures of +10° to +20°C. But the modules with the necessarily higher
emittances, and dissipating a modest 1.0W of power, are only 10°C warmer
than the unpowered condition, running at -25° to -28°C.
I need to further refine this analytic model and to try different power
dissipation situations. I felt, however, that it was necessary for me to
report the results of these analyses to you at this time. These results are
in line with the AO-10 telemetry for an eclipse condition, that was reported
to me many years ago.
73,
Dick Jansson, KD1K
kd1k(a)amsat.org
kd1k(a)arrl.net
Folks,
In the San Francisco Bay Area it looks like most of the 440 MHZ FM repeaters
will have to be shut down to avoid interference with the PAVE PAWS radar
site at Beale Air Force Base in Marysville. That got me thinking that I
might be able to detect the radar from my house even though it is almost 200
miles away and masked by terrain. Sure enough, I think I can. I've
captured data and audio and posted it on my web and on EaglePedia.
Click HERE
<http://www.juanr.com/pages/hobbies/ham_radio/Eagle/PAVE_PAWS.htm> to read
my log and listen to the audio.
73,
Juan - WA6HTP
Perhaps one of you can detail the "multiband antenna" used with the SQRX
receiver aboard AO-51.
A perusal of Gould Smith's "ECHO" makes reference to it but provides no
details.
Does anyone have any in orbit data for this mode. What's the current
status for its use?
Regards and thanks...Bill - N6GHz
