[amsat-bb] Re: Dutch Transponder on-baord HAMSAT VO-52 'Turned On'
Hi Greg, KO6TH In my opinion one lesson the satellite community can learn from this, is that if we want to communicate a satellites should be designed with only one mode and with redundant transponders i.e. strong and stupid BTW after working few orbits it seems to me that the indian transponder was less subject to be overloaded in comparison to the Dutch transponder. If the EIRP is too high and there are many station in the passband the Dutch transponder is FMing and get distorted while the indian transponder was more linear and less subject to be overloaded. If the uplink power is in the order of 10 to 20 watt into a 10 dBi RHCP antenna than the Dutch transponder is not overloaded. I agree with you that it will be very interesting to know from ISRO if the difference in linearity between the above transponders is due to the actual battery conditions or to a different performance of the AGC 73 de i8CVS Domenico - Original Message - From: Greg D ko6th.g...@gmail.com To: Mani VU2WMY w...@isac.gov.in Cc: RANGAN tpran...@istrac.org; AMSAT-INDIA amsatin...@yahoogroups.com; VUHAMS vuh...@yahoogroups.com; PE1RAH pe1...@yahoo.com; BB,AMSAT amsat-bb@amsat.org; VU3TYG vu3...@yahoo.co.in Sent: Thursday, March 15, 2012 4:05 AM Subject: [amsat-bb] Re: Dutch Transponder on-baord HAMSAT VO-52 'Turned On' Hi Mani, Congratulations on the recovery of VO-52; it's great to have our friend back. I am curious if ISRO will be issuing some sort of report on what happened. I understand that they will have limits on what they can say, but if there is something the satellite community can learn from this, it would be good to not miss the opportunity. Greg KO6TH Mani VU2WMY wrote: Dear HAMSAT VO-52 users, The commands to 'Turn On' the transponder # 2 (Dutch transponder, made by Williams PE1RAH) on-board HAMSAT VO-52 was successfully sent during 14:00 UT 35 deg ascending Node pass over Bangalore, India. The sent commands were successfully received, acknowledged and confirmed by the telemetry. Subsequently, the transponder # 2 is now 'ON' and Williams CW message beacon was heard again after a gap of approximately 6 years 4 months. The beacon signal was heard loud and strong here at Bangalore. A detailed Initial reports addressed to: tpran...@istrac.org and a copy to w...@isac.gov.in would be greatly appreciated. 73 de Mani, VU2WMY Secretary Station-In-Charge Upagrah Amateur Radio Club VU2URC ISRO Satellite Centre HAL Airport Road, Bangalore-560 017. Phone:(O)91-80-25082054/2598/2192 Mobile: 91-80-98803 41456 E-mail ID: w...@isac.gov.in vu2wmy_m...@yahoo.com isroh...@yahoo.com -- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -- ___ 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 ___ 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] CO-65 schedule in March
Ground Station of CO-65 announces it as follows. This is information of operation schedule change in March 2012. At present, it is difficult to perform the satellite operation like former because this laboratory moved the other day. And the operative situation largely changed, so we modified the operation schedule in March as follows * Mission operations (APD observation etc...) are not performed. * Digipeter is always open. Please check detail of passes from the following website. URL(Japanese) : http://lss.mes.titech.ac.jp/ssp/cute1.7/operationschedule.html When we will rechange the schedule of operation again, we will inform about it in this blog. Thank you for your understanding. URL(Japanese) : http://lss.mes.titech.ac.jp/ssp/cute1.7/blog/ I, JE9PEL think that Digipeater is always open via JQ1YTC all over the world, uplink 1267.600MHz / downlink 437.475MHz, 9600bps FSK. http://www.ne.jp/asahi/hamradio/je9pel/ct17gmsk.htm JE9PEL, Mineo Wakita ___ 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: Dutch Transponder on-baord HAMSAT VO-52 'Turned On'
On Fri, March 16, 2012 09:33, i8cvs wrote: Hi, BTW after working few orbits it seems to me that the indian transponder was less subject to be overloaded in comparison to the Dutch transponder. If the EIRP is too high and there are many station in the passband the Dutch transponder is FMing and get distorted while the indian transponder was more linear and less subject to be overloaded. If the uplink power is in the order of 10 to 20 watt into a 10 dBi RHCP antenna than the Dutch transponder is not overloaded. I experience the same, last night during the pass from 7:22 p.m. UTC there was an overload on the uplink and therefor it was impossible to use the passband efficient. I also experienced linearity problems. So please reduce power to a minimum - if the transponder is clogged no one benefits. I agree with you that it will be very interesting to know from ISRO if the difference in linearity between the above transponders is due to the actual battery conditions or to a different performance of the AGC 73 de i8CVS Domenico 73 Jan PE0SAT -- With regards PE0SAT Internet web-page http://www.pe0sat.vgnet.nl/ ___ 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] Dutch transponder versus the Indian transponder.
Hi all, The two transponders are not built exactly the same way. The Indian transponder has an AGC - but according to my memory Williams transponder has a diode limiter. I think that can be the difference. In theory the AGC will regulate the gain down so that the stronger station drowns the ones with a lower uplink signal. The diode limiter will of course limit the signal for the strong stations - but also create distortion in a broad frequency range for all stations. That is if there is a very strong signal - or many stations at the same time. Whatever the reason KEEP THE POWER DOWN 73 OZ1MY/Ib ___ 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: Dutch transponder versus the Indian transponder.
Hi Ib, OZ1MY and William, PE1RAH Thank you for the information about the diode limiter into the William's transponder. I got the link of PE1RAH describing the block diagram of indian and Duch transponders but without information about AGC or diode limiter. http://www.qsl.net/pe1rah/HAMSAT-info.htm I hope that William will informe us on this matter. 73 de i8CVS Domenico - Original Message - From: Ib Christoffersen oz...@privat.dk To: pe0...@vgnet.nl Cc: amsat-bb@amsat.org Sent: Friday, March 16, 2012 11:36 AM Subject: [amsat-bb] Dutch transponder versus the Indian transponder. Hi all, The two transponders are not built exactly the same way. The Indian transponder has an AGC - but according to my memory Williams transponder has a diode limiter. I think that can be the difference. In theory the AGC will regulate the gain down so that the stronger station drowns the ones with a lower uplink signal. The diode limiter will of course limit the signal for the strong stations - but also create distortion in a broad frequency range for all stations. That is if there is a very strong signal - or many stations at the same time. Whatever the reason KEEP THE POWER DOWN 73 OZ1MY/Ib ___ 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: Dutch Transponder on-baord HAMSAT VO-52 'Turned On'
Dear Greg, You are very right in all your aspects. 1. We are still in the process of documenting the recent HAMSAT VO-52 Anomaly Analysis and Transponder-2 Switch ON Report. 2 The report will not be complete without the feedback from the user (HAM) community. Hence, we have decided to circulate, very soon a feedback format, at least to all those who have sent us their initial reports. 3 Right now, we are not in a position to share anything with the users.However, once the formal analysis report is approved and released, your request , will be forwarded (justifying that such information will help in future amateur radio satellite ventures) to the Management for further advise. Dear Greg, we hope you understand our position and limitations. 73 de Mani VU2WMY Quoting Greg D ko6th.g...@gmail.com: Hi Mani, Congratulations on the recovery of VO-52; it's great to have our friend back. I am curious if ISRO will be issuing some sort of report on what happened. I understand that they will have limits on what they can say, but if there is something the satellite community can learn from this, it would be good to not miss the opportunity. Greg KO6TH -- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -- ___ 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: Dutch Transponder on-baord HAMSAT VO-52 'Turned On'
If the uplink power is in the order of 10 to 20 watt into a 10 dBi RHCP antenna than the Dutch transponder is not overloaded. Yes, it's important not to run too much power to prevent overloading. I have found that just 300 mW into a 16 dBi vertically polarized antenna works beautifully through most of the pass, during the last few days. Not much power is needed at all. 73 de Dave KB5WIA ___ 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: Dutch transponder versus the Indian transponder.
Hi Domenico I think we have also another problem: In the last few years, the OP's growing up without fullduplex TRX (Ic-706 and similar) and use the ssb sat. They can't hear her own downlink signal from the bird. 73's de Michael HB9WDF, Michael Lipp, JN47AE Am 16.03.2012 um 12:14 schrieb i8cvs domenico.i8...@tin.it: Hi Ib, OZ1MY and William, PE1RAH Thank you for the information about the diode limiter into the William's transponder. I got the link of PE1RAH describing the block diagram of indian and Duch transponders but without information about AGC or diode limiter. http://www.qsl.net/pe1rah/HAMSAT-info.htm I hope that William will informe us on this matter. 73 de i8CVS Domenico - Original Message - From: Ib Christoffersen oz...@privat.dk To: pe0...@vgnet.nl Cc: amsat-bb@amsat.org Sent: Friday, March 16, 2012 11:36 AM Subject: [amsat-bb] Dutch transponder versus the Indian transponder. Hi all, The two transponders are not built exactly the same way. The Indian transponder has an AGC - but according to my memory Williams transponder has a diode limiter. I think that can be the difference. In theory the AGC will regulate the gain down so that the stronger station drowns the ones with a lower uplink signal. The diode limiter will of course limit the signal for the strong stations - but also create distortion in a broad frequency range for all stations. That is if there is a very strong signal - or many stations at the same time. Whatever the reason KEEP THE POWER DOWN 73 OZ1MY/Ib ___ 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 ___ 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: Dutch transponder versus the Indian transponder.
Hi Michael, HB9WDF I think we have another problem too: Since the Dutch transponder is very sensitive someone will attempt to use it in FM using an HT and arrow antenna. 73 de i8CVS Domenico - Original Message - From: Michael Lipp, HB9WDF hb9...@bluewin.ch To: i8cvs domenico.i8...@tin.it Cc: Ib Christoffersen oz...@privat.dk; pe0...@vgnet.nl; pe1...@yahoo.com; Amsat - BBs amsat-bb@amsat.org Sent: Friday, March 16, 2012 2:47 PM Subject: Re: [amsat-bb] Re: Dutch transponder versus the Indian transponder. Hi Domenico I think we have also another problem: In the last few years, the OP's growing up without fullduplex TRX (Ic-706 and similar) and use the ssb sat. They can't hear her own downlink signal from the bird. 73's de Michael HB9WDF, Michael Lipp, JN47AE Am 16.03.2012 um 12:14 schrieb i8cvs domenico.i8...@tin.it: Hi Ib, OZ1MY and William, PE1RAH Thank you for the information about the diode limiter into the William's transponder. I got the link of PE1RAH describing the block diagram of indian and Duch transponders but without information about AGC or diode limiter. http://www.qsl.net/pe1rah/HAMSAT-info.htm I hope that William will informe us on this matter. 73 de i8CVS Domenico - Original Message - From: Ib Christoffersen oz...@privat.dk To: pe0...@vgnet.nl Cc: amsat-bb@amsat.org Sent: Friday, March 16, 2012 11:36 AM Subject: [amsat-bb] Dutch transponder versus the Indian transponder. Hi all, The two transponders are not built exactly the same way. The Indian transponder has an AGC - but according to my memory Williams transponder has a diode limiter. I think that can be the difference. In theory the AGC will regulate the gain down so that the stronger station drowns the ones with a lower uplink signal. The diode limiter will of course limit the signal for the strong stations - but also create distortion in a broad frequency range for all stations. That is if there is a very strong signal - or many stations at the same time. Whatever the reason KEEP THE POWER DOWN 73 OZ1MY/Ib ___ 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 ___ 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: VUCC #227
Congrats! It's a really nice certificate isn't it? Jim - K0BAM VUCC # 209 ___ 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] CO6CBF/p FL02 again
Hello Guys! Tomorrow morning, my girlfriend and I will go to Villa Clara province in FL02. I hope to be operating on the AO-27 and SO-50 passes until Sunday when we will come back. As you know, the birds are very busy because of Yuri ´s operation; anyway if you need this grid confirmed, please contact me off the list and we will try it. 73! Hector, CO6CBF *** Genius is one per cent inspiration, and ninety-nine per cent perspiration. -- Thomas A. Edison *** --- Consulte la Enciclopedia Colaborativa Cubana http://www.ecured.cu/ ___ 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: VUCC #227
Yes it is, bigger than the frame I had ready for it as well. :) Thanks for the grids you gave me as well Jim. Always good to work you. 73 Rick K7TEJ Jim Adams jim9...@gmail.com wrote: Congrats! It's a really nice certificate isn't it? Jim - K0BAM VUCC # 209 ___ 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: VUCC #227
Congratulations Rick. 73, Bob Herrell - AJ5C VUCC #203 ___ 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: VUCC #227
Rick, I just received my VUCC satellite Award today. Certificate # 227. Thanks to all who worked me over the past two years to get me here. Congratulations on getting the award. Hope to hear you again on the birds soon. 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ (VUCC #210) ___ 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] Center of the transponder
Fellow satellite operators, There is nothing particularly magical about the center of the transponder on VO-52 or FO-29. In fact, on FO-29 it is the poorest sounding place in the entire passband. Just because SatPC32 puts you there with the default Doppler.SQF configuration, does not mean every single QSO should take place there. Spread out a little, listen to what is going on, and we'll all make more, and happier, QSOs. I might also add that if a rare station pops up, or makes a habit of operating in one spot, it might be beneficial to call CQ the entire pass somewhere other than the middle of the pile. Even with the previous observations, it is nice to hear many new calls on the transponders. Just remember this isn't AO-51 or AO-27...spin the VFO a bit. I'm looking forward to Funcube and the other new transponders this September. 73, Drew KO4MA ___ 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
