[amsat-bb] Re: transponder
Hi Paolo, PU2PHK I suggest you to contact William PE1RAH at pe1...@yahoo.com 73 de i8CVS Domenico - Original Message - From: Paulinho - PU2PHK pu2...@gmail.com To: amsat-bb@amsat.org Sent: Tuesday, October 16, 2012 6:45 PM Subject: [amsat-bb] transponder Hello I'm doing some experiments and I wonder if anyone has some scheme of a Linear Transponder VHF - UHF to provide me. Now appreciate any help. Thanks. Paulo PU2PHK Brasil ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: transponder
Hello I'm doing some experiments and I wonder if anyone has some scheme of a Linear Transponder VHF - UHF to provide me. Now appreciate any help. Thanks. Paulo PU2PHK Brasil Hello! This is one ready to fly analog transponder: http://www.qsl.net/pe1rah/LE002.htm -jari oh3uw ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: transponder
At the AMSAT-DL meeting in Bochum last weekend William presented a U/V lineartransponder for 1U cubesats (weight only 30 gramms) 73 Mike DK3WN -Ursprüngliche Nachricht- Von: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] Im Auftrag von Jari Koivurinne Gesendet: Mittwoch, 17. Oktober 2012 10:26 An: Paulinho - PU2PHK Cc: amsat-bb@amsat.org Betreff: [amsat-bb] Re: transponder Hello I'm doing some experiments and I wonder if anyone has some scheme of a Linear Transponder VHF - UHF to provide me. Now appreciate any help. Thanks. Paulo PU2PHK Brasil Hello! This is one ready to fly analog transponder: http://www.qsl.net/pe1rah/LE002.htm -jari oh3uw ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Transponder 1412Z
I wish I'd heard you calling, Ray. Still trying to make my first contact through ARISSat, The QSB is a killer. 73 Glenn AA5PK - Original Message - From: rsoi...@aol.com To: amsat-bb@amsat.org Sent: Sunday, August 07, 2011 9:25 AM Subject: [amsat-bb] Transponder 1412Z I heard myself calling CQ for about 2 minutes, peaking 569, but no takers that I could hear. Then, about 2 minutes later, I heard AA5PK calling CQ, about the same strength, but I could no longer hear myself. It's a challenge! 73 Ray W2RS ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Transponder 1412Z
Hi Glenn, I haven't made a QSO yet either. The biggest problem, I think, is the satellite's tumbling, which results in frequent obstruction of the little uplink antenna by the main body of the spacecraft. On this pass, when I could see the uplink antenna, you couldn't, and vice versa. The rapid Doppler, due to the low altitude, doesn't help either. I'll try again tomorrow morning. 73 Ray In a message dated 8/7/2011 2:42:54 P.M. GMT Standard Time, aa...@suddenlink.net writes: I wish I'd heard you calling, Ray. Still trying to make my first contact through ARISSat, The QSB is a killer. 73 Glenn AA5PK - Original Message - From: rsoi...@aol.com To: amsat-bb@amsat.org Sent: Sunday, August 07, 2011 9:25 AM Subject: [amsat-bb] Transponder 1412Z I heard myself calling CQ for about 2 minutes, peaking 569, but no takers that I could hear. Then, about 2 minutes later, I heard AA5PK calling CQ, about the same strength, but I could no longer hear myself. It's a challenge! 73 Ray W2RS ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Transponder 1412Z
Ray, I could hear myself extremely well also using about 20 watts. I tried SSB and CW no takers. I was trying around center of pass band. Will listen for other next time instead of running my big mouth. 73, Jeff - K2AK DM41 -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of rsoi...@aol.com Sent: Sunday, August 07, 2011 7:26 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Transponder 1412Z I heard myself calling CQ for about 2 minutes, peaking 569, but no takers that I could hear. Then, about 2 minutes later, I heard AA5PK calling CQ, about the same strength, but I could no longer hear myself. It's a challenge! 73 Ray W2RS ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Transponder 1412Z
Ray, I heard you solid, 589, with some QSB, but never faint. I didn't reply because I was going back and forth to 145.825 to see if the packet was operational (it was not). I did not hear the reported QRM from packet bursts over that pass (Pacific, SoCal, Baja). 73, Jerry, K5OE original message - I heard myself calling CQ for about 2 minutes, peaking 569, but no takers that I could hear. Then, about 2 minutes later, I heard AA5PK calling CQ, about the same strength, but I could no longer hear myself. It's a challenge! 73 Ray W2RS ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Transponder
No joy on the 12:00Z pass (48 deg max elev) here... could hear the CW beacon, BPSK, and FM transmissions with deep fades, but otherwise quite well. No other stations heard in the transponder passband, nor could I hear myself on the downlink, from 5 to 75 watts uplink using omnis (M2 eggbeater w/preamp on the downlink, homebrew turnstile on the uplink). Next pass here not until 04:30Z. It doesn't appear that the satellite has any active or passive attitude control system. I have heard that the spin should eventually settle around the same axis as the antenna, but is there any reasonable hope that that would happen during the satellite's operational lifetime? George, KA3HSW - Original Message From: rsoi...@aol.com rsoi...@aol.com To: amsat-bb@amsat.org Sent: Sat, August 6, 2011 8:48:21 AM Subject: [amsat-bb] Transponder On the ARISSat-1 pass just ended here (23 degrees max elevation), results were about the same as yesterday. I heard my CW downlink for about a minute, peaking 559. Several other CW signals were in there, but I couldn't get their calls due to the deep fades. Bruce appears to be right that the transponder's performance depends largely on the spacecraft's orientation. 73 Ray W2RS ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Transponder
On 8/6/11 8:23 AM, George Henry wrote: It doesn't appear that the satellite has any active or passive attitude control system. Correct. I have heard that the spin should eventually settle around the same axis as the antenna, but is there any reasonable hope that that would happen during the satellite's operational lifetime? Good question. Theory says it will *eventually* happen, but how fast depends on the mechanisms to dissipate mechanical energy in the spacecraft. Because the frame and the modules inside are so rigid, I think the flexible 2m antenna will probably do most of the work. One way to follow this is to measure the satellite's spin period very accurately over time. Assuming no external torque (e.g., atmospheric drag, which will eventually become significant) then the spacecraft must conserve its original angular momentum. But as it dissipates excess energy and converts to a spin around the preferred axis (i.e., shifts its angular momentum to the body axis with the greatest moment of inertia), the spin rate will decrease. E.g., if the moment of inertia around the axis of initial spin is, say, 1, and the moment of inertia around the preferred (antenna) axis is 3, then after it settles down the spin rate will be 1/3 of its original value. So if we can follow the spin rate over time we can predict how long it'll take to reach a stable spin around the antenna axis. That does require knowledge of the moments and products of inertia, which I assume were measured before launch. 73, Phil ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
