July 2007 - Eagle (INACTIVE) - mailman.amsat.org

TS channel recreated
by Robert McGwier 10 Jul '07

10 Jul '07

I have no idea what happened. I recreated it AMSAT Engineering, password eagle1 and since it is fortunate I cannot remember what day of the week it is, I will see you folks tonight. 73's 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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Teamspeak
by Dick-rr 09 Jul '07

09 Jul '07

With the bringing of the new computer on line, I discover that I do not have the information needed to bring up the Teamspeak connection. Can someone help me today so that I can be available tonight? Dick, KD1K

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TeamSpeak conference for 10 July
by Jim Sanford 09 Jul '07

09 Jul '07

Team: Reminder, our next conference is next Tuesday at 2100 EDT, 1800 PDT, and 0100Z. I will write the agenda (much) later tonight. If you have inputs, pls get to me, or feel free to modify mine, once I load it on EaglePedia. Thanks & 73, Jim wb4gcs(a)amsat.org

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First Temperature Run on the 70cm Receiver
by Juan Rivera 06 Jul '07

06 Jul '07

Greeting! I hope you are all having a great 4th of July! And as Jim says, please give a kind thought to the folks over in the Mid East. The temperature over there in the summer gets up to about 135 in the sun. It's a miserable environment just trying to walk from one place to another in a tee shirt. I can't imagine how anyone can grunt 40 or 50 pounds of equipment and have to worry about getting blown up. Believe me. They all earn their pay! Early this morning I started setting up for the first temperature run on the prototype 70cm Eagle Receiver. Unfortunately I believe that the master oscillator has got to go. I'll verify my suspicion this evening when the temperature in the shack drops back down to survivable levels... Please take a look and my report by clicking HERE <http://www.juanr.com/pages/hobbies/ham_radio/Eagle/Temperature_Run.htm> and look for the three audio wav files towards the end. 73, Juan - WA6HTP

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70cm Receiver Temperature Run in External Reference Mode.
by Juan Rivera 05 Jul '07

05 Jul '07

All, I ran a Temperature Run on the 70cm Receiver in External Reference Mode. Click HERE <http://www.juanr.com/pages/hobbies/ham_radio/Eagle/Temperature_Run.htm> for details... 73, Juan

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70 cm Frequency Stability Tests Results
by Juan Rivera 04 Jul '07

04 Jul '07

All, I should have gone to work today but I ended up working on the 70 cm Receiver all day instead. Today marks a milestone for me -- my first use of audio files. You'll find two in my write up if you click HERE <http://www.juanr.com/pages/hobbies/ham_radio/Eagle/Stability.htm> . I think they work much better than descriptions and graphs. Now you can hear what I'm talking about... Have a great 4th! I plan to do a temperature run on the receiver tomorrow to celebrate! Let's see what that internal oscillator does when it's not at room temperature! P.S. to OSCAR guys... If you have time come on over and help me run this test. I'll probably start early to beat the heat. If you've never been gassed by CO2 before, now is your chance! 73, Juan - WA6HTP

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TeamSpeak conference for Tuesday 10 July 2007
by Jim Sanford 04 Jul '07

04 Jul '07

All: For whatever reason, I'm unable to update EaglePedia (it ignores my changes), so here's the agenda as I see it. Feell free to suggest additons to me, I'll keep a running total and publish just prior to the meeting. Topics: 1. Symposium 2. Requirements documentation ' 3. WBS and schedule development 4. Status reports UHF RX S2 Rx 5, EMI Please add topics. Thanks & 73, Jim wb4gcs(a)amsat.org

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70 cm Receiver Frequency Stability and One More Glitch
by Juan Rivera 03 Jul '07

03 Jul '07

All, Here's a plot of frequency drift in the 70 cm Receiver - first on internal reference, then on external reference: The first part of the plot is with the receiver and the signal generator set to 435.500000 MHz on internal reference. You can see the slow steady drift upwards of about 15 Hz over a period of about 5 minutes. Then I reinitialized the receiver for the external reference. It locked right up and the output was exactly 10.700000 MHz where it stayed. The most important thing I noticed is not on this graph. With internal reference selected, but while feeding 10 MHz into the external reference input, (as it might be configured in flight) the two reference signals are beating together. It wasn't until I started listening to the output of the receiver by patching it into a distribution amplifier so I can feed my counter, the SDR-IQ, the TS-2000, and the HP 8566B all at once that I noticed it. The result is that the input signal is FM modulated by the beat between the two reference oscillators. I also noticed some unexplained jumps in frequency that I have not yet been able to capture. I'll dig into this again when I have more time. 73, Juan

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CAN-Do Causing RF Frequency Jumps in 70 cm Receiver
by Juan Rivera 03 Jul '07

03 Jul '07

John and CAN-Do Team, I was in the process of checking some configuration files in preparation for my hunt for the 10.7 MHz spur. I initialized the receiver on 435.500, internal reference, and set up the SDR-IQ to display the IF output signal. Then I clicked the heartbeat button on the Can-Do Net Controller and was about to load the initialization file for external reference. As soon as I clicked the heartbeat button the IF output started jumping. I think it's the three second jumps that I have seen before, but I thought those were caused by a momentary loss of DC input power. In this case the receiver power is coming directly from the bench supply. I killed the CAN-Do module power and the IF jumping stopped. As soon as I applied power to the CAN-Do module again, the jumping returned. The duration of the jumps is very short and I am unable to capture a carrier - either with the SDR-IQ or using my TS-2000. They sound like clicks over a wide frequency range. Since the next revision of the receiver will be autonomous, perhaps this won't be an issue for us, but it will for others so it should be understood and documented in my opinion. 73, Juan

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10.7 MHz Spur
by Juan Rivera 03 Jul '07

03 Jul '07

John, I found the source of the 10.7 MHz spur. It's being generated inside the receiver itself. This is the first spur I have found that is not caused by switching power supplies. The origin appears to be in the 10 MHz reference area. I turned off and unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my TS-2000. The spur is still there. Next I connected the RF input to my sniffer loop and moved it around the PCB surface. I get the strongest signal near the long trace between the two Freq inputs to U4 and U9, the two phased-locked loops. 73, Juan

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