September 2007 - AMSAT-BB - mailman.amsat.org

AO-51 September schedule
by Andrew Glasbrenner 03 Sep '07

03 Sep '07

Hello all, I posted the new schedule to http://www.amsat.org/amsat-new/echo/CTNews.php Saturday morning. I apologize for it not being uploaded earlier. Thanks to the AO-51 committee for another great balance of modes this schedule. Now for some notes on the satellite. We are currently running 370 mW on TXA (435.150) and 630 mW on TXB (435.300). Power levels will continue to increase as eclipses get shorter, leading up to 10 weeks of continuous sun early next year. These are going to be interesting times. Keep in mind that anytime we have something other than telemetry running on TXA (i.e. L/U repeater), we may have to interrupt it occasionally for telemetry and satellite maintenance. Our lead command station, Gould WA4SXM, has been doing an outstanding job of squeezing every last drop of power for the downlinks. Enjoy the satellite, and remember it's never too early to submit your mode requests for October to ao51-modes(a)amsat.org . 73, Drew KO4MA AMSAT-NA VP Ops September 2007 AO-51 (AMSAT Echo) Schedule September 1 until September 30, subject to modification September 1 - September 10 FM Repeater, V/U Uplink: 145.920 MHz FM, No PL Tone Downlink: 435.300 MHz FM 9k6 Digital, V/U, Telemetry Only Downlink: 435.150 MHz FM, 9k6 Telemetry September 10 - September 14 FM Repeater, L/S Uplink: 1268.700 MHz FM, No PL Tone Downlink: 2401.200 MHz FM September 14 - September 17 FM Repeater, V/U Uplink: 145.920 MHz FM, No PL Tone Downlink: 435.300 MHz FM 9k6 Digital, V/U, Telemetry Only Downlink: 435.150 MHz FM, 9k6 Telemetry September 17 - September 21 SSB/FM Repeater, V/U Uplink: 145.880 MHz USB Downlink: 435.300 MHz FM 9k6 Digital, V/U, Telemetry Only Downlink: 435.150 MHz FM, 9k6 Telemetry September 21 - October 1 FM Repeater, V/U Uplink: 145.920 MHz FM, No PL Tone Downlink: 435.300 MHz FM FM Repeater, L/U (subject to interuption for satellite maintenance) Uplink: 1268.700 MHz FM, No PL Tone Downlink: 435.150 MHz FM

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Wanted.... Rohn BPL45G
by Stargate 03 Sep '07

03 Sep '07

Hi all, I'm looking for a Rohn BPL45G flat top adaptor with or without thrust bearing for 45G tower. I had a deal working on one, but it fell through. If anyone has one to sell/trade, please contact me at.... sad.tip(a)verizon.net P.S. Sorry for all the cross posting, and it might be a bit OT for some of the groups, but I can't seem to find one locally. Thanks, RoD KD0XX A good friend will come and bail you out of jail, A TRUE friend will be sitting next to you saying..... "DAMN THAT WAS FUN"

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Re: doppler.
by k1uxbma＠comcast.net 02 Sep '07

02 Sep '07

Hello all. My husband Nick (K1UXB) passed away last February 3, 2007. He had been a Ham operator since age 15. He was 71 when he passed. Do you know anyone in Massachusetts (I am in Medford) that needs equipment ? I can send you Model #'s etc. He also has lots of huge antennas here at the house. Please call if you or anyone you know is interested. He would appreciate the equipment being put to good use. Sincerely, Alice (781) 395-4509 Please forward this e-mail to contact anyone who would be interested. Thanks. -------------- Original message -------------- From: "John Hackett" <archie.hackett(a)hotmail.com> > Hi All, > Re: doppler. I've attached K4GMJ's article from the August 1992 > issue of Oscar News. It may be of interest to those, like me, who still use > old equipment. > > In addition to Maury's notes, I can mention, I have used an NE 567 tone > decoder IC and a LED as the visual receiver with a simple twin-T audio > oscillator for the transmitted signal. > A simple twin-T osc: is better than an NE555 in this application. > > I still operate with the Yaesu 290/790 pair + associated homebrew aerials > and amps (over 20 years now) and manage quite nicely on VO-52 with > InstantTUNE. When set up correctly, the signals track perfectly so even with > "old" equipment it's still possible to adhere to THE ONE TRUE RULE regarding > doppler. > > I don't tune at all for doppler on AO-7. > > Occasionally, just for fun, I tune manually ... (transmitter and receiver) > .... to keep the frequency constant at the satellite, however ... be aware > .... it is *NOT* mandatory to keep the signal fixed at the satellite. Many > operators still use the manual convention of tuning the highest frequency > .... (because it has the highest doppler rate). > > This is perfectly acceptable because not everybody is either 1) affluent > enough to be able to afford the latest all singing, all dancing multimode > rig ... or 2) not experienced enough to cope with doppler on the uplink and > the downlink at the same time. > > 73 John. >

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Polarization Switcher
by i8cvs 02 Sep '07

02 Sep '07

Hi Joe, KC2TN My answere to you about the polarization switcher was rejected by comcast.net Send me please another email address 73" de i8CVS Domenico

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Re: doppler.
by John Hackett 02 Sep '07

02 Sep '07

Hi All, Re: doppler. I've attached K4GMJ's article from the August 1992 issue of Oscar News. It may be of interest to those, like me, who still use old equipment. In addition to Maury's notes, I can mention, I have used an NE 567 tone decoder IC and a LED as the visual receiver with a simple twin-T audio oscillator for the transmitted signal. A simple twin-T osc: is better than an NE555 in this application. I still operate with the Yaesu 290/790 pair + associated homebrew aerials and amps (over 20 years now) and manage quite nicely on VO-52 with InstantTUNE. When set up correctly, the signals track perfectly so even with "old" equipment it's still possible to adhere to THE ONE TRUE RULE regarding doppler. I don't tune at all for doppler on AO-7. Occasionally, just for fun, I tune manually ... (transmitter and receiver) .... to keep the frequency constant at the satellite, however ... be aware .... it is *NOT* mandatory to keep the signal fixed at the satellite. Many operators still use the manual convention of tuning the highest frequency .... (because it has the highest doppler rate). This is perfectly acceptable because not everybody is either 1) affluent enough to be able to afford the latest all singing, all dancing multimode rig ... or 2) not experienced enough to cope with doppler on the uplink and the downlink at the same time. 73 John. <la2qaa(a)amsat.org>

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Re: AO-7
by John Hackett 02 Sep '07

02 Sep '07

Mak, We're on the same page ... those were EXACTLY my thoughts too. I'm fully expecting "you know who" to jump in later today and say ... I TOLD YOU SO ... but until I posted my mails from Jan King last week, those two individuals didn't have all the facts ... and probably believed the information in the 1974 Amsat newsletter ... (which as we now know, was NOT correct). Like you say, it will be VERY interesting to see what happens regarding AO-7 modes in the next few days. I hope you don't mind me posting your comments on the Amsat-bb ... I believe your observation is VERY important in understanding the randomness of the switching circuitry. GM1SXX and I have another theory but it's a bit too soon to get flamed! for this, we need to wait until after Christmas to make it an even 4 years. NB. Both GM1SXX and myself have ALWAYS maintained that there is some !!! battery power ... but not enough to operate the transponders ... we collected VALID data in 2005/6 ... that would explain your observation Mak. I'll rope Joe in ... (kicking and screaming!) ... so that we have monitors in K3, LA and SV so we can see how things progress. I checked with QRZ.COM before publishing your e-mail address. 73 John. <la2qaa(a)amsat.org> ........................................................................................................................................ >From: "SV1BSX" <sv1bsx(a)yahoo.gr> >To: <la2qaa(a)amsat.org> >Subject: AO-7 >Date: Sun, 2 Sep 2007 11:38:48 +0300 > > Good morning John, > > well I am wake from early morning today and I noticed that (after K3SZH >Email) AO-7 is in Mode-A, >almost permantly for the last 4 orbits (#50076-9). > > I'm not 100% sure about 50077 orbit, I missed that, but the last 2 >(#50078 & 9) is glued to Mode-A. >Unusual because as I was looking just now on NOVA, between 07:21 - 07:24 >UTC AO-7 was into a short eclipse period, >without any changing in Mode. > > He he.... it should be funny to stay for a couple of days "glued" to >Mode-A. > >Have a nice Sunday > >73, Mak

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Mode-A
by John Hackett 02 Sep '07

02 Sep '07

Hi All, I confirm AO-7 was in mode-A on orbit 50087 today, Sunday 02-09-07. The two stations eagerly waiting in the wings to jump out and say ... 'I told you so' ... relax !, I've got it ... ONE OF LA2QAA's EARLIER ASSUMTIONS WAS WRONG ... an actual human error no less. Signals this morning were "weak & watery" ... (I heard nobody else in the passband). It will be interesting to see if the activity is almost zero in mode-A vis-a-vis mode-B as it has been on previous occasions. After the "referendum" ... (G1WPR and K3SZH and one other station took the trouble to reply) ... the AO-7 log will remain unchanged. Like the other station said, everybody can see who fills out the log incorrectly. 73 John. <la2qaa(a)amsat.org>

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FO-29 CW telem 2007-09-01 15:19Z
by Bruce Robertson 02 Sep '07

02 Sep '07

I found the bird much louder last night than the night before, when I was unable to copy telem. On that occasion, the beacon power might have been compressed by rogue FM signals on the transponder. I assume that since the tx power is stated as around 0.8W, the beacon is running 80mW, about the same as some cubesats. HI HI 22 E2 88 D5 8F BB 05 25 00 24 00 00 6F 65 9A 9D B0 80 B7 B6 B7 B5 BA HI HI 22 2E 88 D5 8F BB 05 25 00 24 00 00 6F 65 9A 9D B1 91 B7 B6 B6 B4 BA HI HI 22 E2 88 D5 8F BB 05 25 00 24 00 00 6E 65 9A 9D B0 88 B7 B6 B6 B5 BA HI HI 22 E2 88 D5 8F BB 05 25 00 24 00 00 6C 65 9A 9D B0 80 B7 B6 B6 B4 B9 DATA 1 Main Relay ON : DCM ON SRAM OFF : Packet OFF JTA ON : JTD OFF GAS OFF : SAS OFF : UVC ON UVC Level 1 : PCU Mode AUTO PCU Level 3 : Battery Mode TRIC Battery Logic TRIC : Digitalker Mode OFF : UVC ACT/PAS PAS CPU RUN/RESET RUN : Spin Period 8356.0 [msec] Sun Angle 72.5 [deg] GAS-Z 0.0 [nT] GAS-X 0.0 [nT] Solar Panel Current 1088.2 [mA] Battery Current -20.4 [mA] Battery Voltage 16.6 [V] Battery Middle Voltage 7.6 [V] Bus Voltage 17.3 [V] Analog Tx Power 733.9 [mW] Structure Temp. 1 10.8 [C] Structure Temp. 2 11.2 [C] Structure Temp. 3 10.8 [C] Structure Temp. 4 11.6 [C] Battery Cell Temp. 9.6 [C] It is interesting to see the solar panel current decrease as the bird moves toward eclipse. (I assume since this is a sphere that these changes represent represent real alterations in irradiation, not the effects of tumble, but I'd be happy to be corrected on this point.) Solar Panel Current (# 50mA) ( Data 1 ) 1088.2[mA] : ###################### ( Data 2 ) 1088.2[mA] : ###################### ( Data 3 ) 1078.4[mA] : ###################### ( Data 4 ) 1058.8[mA] : ##################### Unfortunately, I decided to see if anyone was active on the transponder and missed the frames of telemetry that came during and after eclipse. Thanks to JE9PEL, Mineo, for his excellent telemetry analysis program. 73, Bruce VE9QRP

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AO7 info
by k3szh＠netzero.net 02 Sep '07

02 Sep '07

Hi all At 1:56 utc AO7 was in mode "A" my signal was 5/8 to S9 ,just heads up. Joe K3SZH AMSAT 3788

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AO7 question
by tjjapha＠earthlink.net 02 Sep '07

02 Sep '07

I must have missed something! AO7 is a great bird despite all the FMing, but one thing puzzles me: the rx freq. is always WAY off the calculated freq. based on the translation between the bands. Isn't it supposed to be 145.950 down for 432.150 up, and inversely related (145.948=432.152, etc.)? If it is, it isn't that in reality! What's the real deal? IOf course it's all +/- doppler, but early in the pass, my doppler shift is below the nominal freq. Yikes! Tnx & 73, Tony, N2U

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