Eagle (INACTIVE) September 2007

17 participants
12 discussions

70 cm Receiver on external reference
by Juan Rivera 19 Sep '07

19 Sep '07

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

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YAHOO!!!! IT WORKS!!!!
by Juan Rivera 18 Sep '07

18 Sep '07

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

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Re: I need another CAN-Do Module
by Robert McGwier 16 Sep '07

16 Sep '07

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

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Re: 70 cm receiver inoperative with new CAN-Do module - More
by Juan Rivera 16 Sep '07

16 Sep '07

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

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70 cm receiver inoperative with new CAN-Do module
by Juan Rivera 16 Sep '07

16 Sep '07

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

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Module Temperatures & Eclipse
by Dick Jansson-rr 16 Sep '07

16 Sep '07

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

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TS?
by Dick Jansson-rr 12 Sep '07

12 Sep '07

Is there to be a TeamSpeak meeting tonight? Is there anything to talk about? Dick Jansson, KD1K kd1k(a)amsat.org kd1k(a)arrl.net

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Going into the deep Echo archives.
by Tom Clark, K3IO 06 Sep '07

06 Sep '07

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PAVE PAWS EMI
by Juan Rivera 05 Sep '07

05 Sep '07

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

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AO-51 Multiband Antenna???
by Bill Ress 04 Sep '07

04 Sep '07

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

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Eagle (INACTIVE) September 2007