April 2018 - AMSAT-BB - mailman.amsat.org

Re: [amsat-bb] Tiangong Re-entry (0000 UTC +/- 2.5 hrs)
by Roger 02 Apr '18

02 Apr '18

You have to manually refresh, F5. 73, Roger W7TZ CN83ia Grid Busters w7tz.webs.com On Sun, Apr 1, 2018 at 5:15 PM, Greg D <ko6th.greg(a)gmail.com> wrote: > Ah, interesting site. Wouldn't it be fitting if it returned to the launch > site. Looks like it might pass just under... > > For a change, Australia isn't a target this time :). > > Greg KO6TH > > > > Roger wrote: > > http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png > > Shows it on what's expected to be it's last orbit. > > > 73, Roger > W7TZ > CN83ia > Grid Busters > w7tz.webs.com > > On Sun, Apr 1, 2018 at 5:03 PM, Greg D <ko6th.greg(a)gmail.com> wrote: > >> I just updated the keps on gPredict, and Tiangong-1 disappeared from the >> list. Where'd it come down, or are rumors of its demise ever so >> slightly exaggerated? Heavens-above still thinks it's up there. >> >> Greg KO6TH >> >> >> Robert Bruninga wrote: >> > Since this is journalism, I think you and some others are right. If one >> > simply looks at latitude as a number, then the latitude near the >> > inclination will have a higher probability of appearing. But the best >> > feedback came from Ralph W0RPK who pointed out this page which is >> tracking >> > the orbit with updated predictions: >> > http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png >> > >> > And the USA is about as far as you can get from the predicted impact. >> The >> > USA is 12 hours out of cycle with the orbit. >> > >> > The prediction there is currently showing about 0000 UTC which is 8 PM >> EDT >> > plus or minus 2.5 hours. (which is about 3 orbits worth). And although >> > those orbits cover a vast Pacific and Atlantic oceans, a good portion of >> > them cross the middle east through Russia and china. >> > >> > Bob, WB4APR >> > >> > On Sun, Apr 1, 2018 at 11:26 AM, Gary Bender, WS5N <ws5n(a)wildblue.net> >> > wrote: >> > >> >> I was thinking the favoring of higher latitudes for reentry was because >> >> the apparent sine wave of the ground track naturally slows down in >> >> "latitude velocity" as it peaks at 43 degrees and reverses. Add in the >> >> rotation of the earth under it and you end up with a bit more dwell >> time >> >> above 38 degrees. It is changing latitude much faster between the >> >> extremes. (Or maybe I am over thinking it.) >> >> -- >> >> Gary, WS5N >> >> >> >> ----- Original Message ----- >> >> From: "Robert Bruninga" <bruninga(a)usna.edu> >> >> To: "amsat bb" <amsat-bb(a)amsat.org> >> >> Cc: "TAPR APRS Mailing List" <aprssig(a)tapr.org> >> >> Sent: Saturday, March 31, 2018 5:55:17 PM >> >> Subject: Re: [aprssig] [amsat-bb] Tiangong Re-entry on Heavens bove >> >> >> >>> Hi Bob, do you know the object number by chance? >> >> No, but this link shows that the higher probabilities or re-entry are >> >> between about 38 to 43 degree latitudes north and south. >> >> >> >> https://www.theguardian.com/science/2018/mar/30/chinas-tiang >> ong-1-space-st >> >> ation-will-crash-to-earth-this-weekend >> >> <https://www.theguardian.com/science/2018/mar/30/chinas-tian >> gong-1-space-st%0Aation-will-crash-to-earth-this-weekend> >> >> >> >> Im not sure why those would be slightly higher. 43 degrees is its >> maximum >> >> excursion (matches its inclination)... Maybe its because as it passes >> >> over the equatorial bulge, it sees the higher drag and that will start >> the >> >> demise which will occur then 20 minutes later? >> >> >> >> Bob >> >> -----Original Message----- >> >> From: Robert Bruninga >> >> Sent: Saturday, March 31, 2018 9:16 AM >> >> Subject: [amsat-bb] Tiangong Re-enetry on Heavens bove >> >> >> >> You can see the live track of Taengong to re-enter in the next 24 >> hours on >> >> http://www.heavens-above.com/ >> >> >> >> Just remember, as it suffers increased drag, it will speed up and be >> ahead >> >> of classic predictions. >> >> >> >> But at least you can see when you are under the orbit as to whether it >> is >> >> worth going outside. I 'd go out several minutes before the prediction >> >> since we dont know how quickly they are updating the elements as it >> speeds >> >> up. >> >> >> >> and even if it is daytime, you will see it if it comes in in your >> area... >> >> >> >> Bob >> >> _______________________________________________ >> >> Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available >> to >> >> all interested persons worldwide without requiring membership. Opinions >> >> expressed are solely those of the author, and do not reflect the >> official >> >> views of AMSAT-NA. >> >> Not an AMSAT-NA member? Join now to support the amateur satellite >> program! >> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb >> >> _______________________________________________ >> >> aprssig mailing list >> >> aprssig(a)tapr.org >> >> http://www.tapr.org/mailman/listinfo/aprssig >> >> >> > _______________________________________________ >> > Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available >> > to all interested persons worldwide without requiring membership. >> Opinions expressed >> > are solely those of the author, and do not reflect the official views >> of AMSAT-NA. >> > Not an AMSAT-NA member? Join now to support the amateur satellite >> program! >> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb >> >> _______________________________________________ >> Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available >> to all interested persons worldwide without requiring membership. >> Opinions expressed >> are solely those of the author, and do not reflect the official views of >> AMSAT-NA. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb >> > > >

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Tiangong Re-entry (0000 UTC +/- 2.5 hrs)
by Robert Bruninga 02 Apr '18

02 Apr '18

Since this is journalism, I think you and some others are right. If one simply looks at latitude as a number, then the latitude near the inclination will have a higher probability of appearing. But the best feedback came from Ralph W0RPK who pointed out this page which is tracking the orbit with updated predictions: http://www.aerospace.org/CORDSuploads/TiangongStoryboard.png And the USA is about as far as you can get from the predicted impact. The USA is 12 hours out of cycle with the orbit. The prediction there is currently showing about 0000 UTC which is 8 PM EDT plus or minus 2.5 hours. (which is about 3 orbits worth). And although those orbits cover a vast Pacific and Atlantic oceans, a good portion of them cross the middle east through Russia and china. Bob, WB4APR On Sun, Apr 1, 2018 at 11:26 AM, Gary Bender, WS5N <ws5n(a)wildblue.net> wrote: > > I was thinking the favoring of higher latitudes for reentry was because > the apparent sine wave of the ground track naturally slows down in > "latitude velocity" as it peaks at 43 degrees and reverses. Add in the > rotation of the earth under it and you end up with a bit more dwell time > above 38 degrees. It is changing latitude much faster between the > extremes. (Or maybe I am over thinking it.) > -- > Gary, WS5N > > ----- Original Message ----- > From: "Robert Bruninga" <bruninga(a)usna.edu> > To: "amsat bb" <amsat-bb(a)amsat.org> > Cc: "TAPR APRS Mailing List" <aprssig(a)tapr.org> > Sent: Saturday, March 31, 2018 5:55:17 PM > Subject: Re: [aprssig] [amsat-bb] Tiangong Re-entry on Heavens bove > > > Hi Bob, do you know the object number by chance? > > No, but this link shows that the higher probabilities or re-entry are > between about 38 to 43 degree latitudes north and south. > > https://www.theguardian.com/science/2018/mar/30/chinas-tiangong-1-space-st > ation-will-crash-to-earth-this-weekend > <https://www.theguardian.com/science/2018/mar/30/chinas-tiangong-1-space-st%…> > > Im not sure why those would be slightly higher. 43 degrees is its maximum > excursion (matches its inclination)... Maybe its because as it passes > over the equatorial bulge, it sees the higher drag and that will start the > demise which will occur then 20 minutes later? > > Bob > -----Original Message----- > From: Robert Bruninga > Sent: Saturday, March 31, 2018 9:16 AM > Subject: [amsat-bb] Tiangong Re-enetry on Heavens bove > > You can see the live track of Taengong to re-enter in the next 24 hours on > http://www.heavens-above.com/ > > Just remember, as it suffers increased drag, it will speed up and be ahead > of classic predictions. > > But at least you can see when you are under the orbit as to whether it is > worth going outside. I 'd go out several minutes before the prediction > since we dont know how quickly they are updating the elements as it speeds > up. > > and even if it is daytime, you will see it if it comes in in your area... > > Bob > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to > all interested persons worldwide without requiring membership. Opinions > expressed are solely those of the author, and do not reflect the official > views of AMSAT-NA. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ > aprssig mailing list > aprssig(a)tapr.org > http://www.tapr.org/mailman/listinfo/aprssig >

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L band
by Bob- W7LRD 01 Apr '18

01 Apr '18

Hello everyone -I finally got my 1.2ghz working! Running a IC-910/ 10W, to a 24 element looper through 70 feet of LMR600. Thanks for the QSO with K7ULS and N7AGF, several more heard. Unfortunately I had to run everything manually, az/el, doppler etc. I forget but what does that gleitkommadivision durch null mean. I know it's divide by zero, but not sure why my satpc32 does not like it with AO-92 running. I have a 16 turn RHCP helix I want to try. Could use more than 24 hours per week. Next we need a linear satellite with L band. 73 Bob W7LRD

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VUCC Awards-Endorsements for March 2018
by Ronald G. Parsons 01 Apr '18

01 Apr '18

Here are the endorsements and new VUCC Satellite Awards issued by the ARRL for the period March 1, 2018 through March 31, 2018. Congratulations to all those who made the list this month! There were several calls which decreased by one this month. These are not listed below. CALL 1Mar18 1Apr18 KK5DO 780 781 WA5KBH 659 728 N4UFO 715 724 N9IP 574 589 W5RKN 554 575 N9EAT 410 428 WD9EWK 400 425 KE4AL 252 317 K7TAB 274 306 W7QL 275 300 AA8CH 104 175 PT2AP 102 172 PS8ET 127 157 N3GS 101 130 N7AGF 101 126 G0ABI 116 122 AL6D 112 (NEW VUCC) W1AT 102 (NEW VUCC) If you find errors or omissions. please contact me off-list at <mycall>@<mycall>.com and I'll revise the announcement. This list was developed by comparing the ARRL .pdf listings for March 1, 2018. and April 1, 2018. It's a visual comparison so omissions are possible. Apologies if your call was not mentioned. Thanks to all those who are roving to grids that are rarely on the birds. They are doing most of the work! 73, Ron W5RKN

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Lindenblad or DCA???
by Hans (BX2ABT) 01 Apr '18

01 Apr '18

Hello all, Been reading up on satellite antennas and something is not clear to me: are the Lindenblad and Double Cross Antenna (DCA) one and the same beast, or not? They look the same and the only difference I can find is that the Lindenblad seems to be slanted 30 degrees towards the horizon and the DCA 60 degrees. Any old timer here who can enlighten me on this? 73 from a sat newbie. Hans BX2ABT

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Funcube 1 (AO-73) vs NAYIF-1 (EO-88) Beacon Power ?
by Iain Young, G7III 01 Apr '18

01 Apr '18

Hi All, I have been trying to find out what the Beacon Power Output of NAYIF-1 is, but have come up blank with my google searches. Is it just part of the 500mW transponder ? Or is there a separate dedicated amount as in AO-73 [Which is 300mW beacon mode, 30mW transponder mode] ? Essentially, I can decode NAYIF-1 Telemetry. I can also decode AO-73 telemetry when the beacon is in high power (300mW), but not when AO-73 is in Transponder mode, where the beacon is only 30mw (-10dB). Depending on the power output of NAYIF-1, I may be able to determine if I really need a 10dB improvement in order to receive AO-73 telemetry while in transponder mode, or if I am in fact, only need 3 or 6db improvement, which could change my strategy (This is a very small station in an urban environment running off a Raspberry Pi 3, with non steerable antennas, and I'm seeing it as an engineering experiment) 73s Iain PS, *grumble* They are too close together frequency wise. Due to AO-73's frequency issues when coming out of eclipse, I need a wider (software) BPF. This means NAYIF-1 manages to not only hit it's own decoder, but AO-73s as well! Great Fun checking if both were visible at the same time here, and then going, "Has to be NAYIF-1!"

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Required- Tone module
by Nitin Muttin 01 Apr '18

01 Apr '18

Friends, I am in need of a ICOM UT-84 Tone module. If anyone willing to sell please contact me direct. 73 Nitin [VU3TYG]

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cube sat question
by Nick Pugh 01 Apr '18

01 Apr '18

We are flying Trisol solar cells and have been recommended to use CV10-2500 by NUSEL for UV protection. The cost is $850 for 50grams. Question is the a less expensive alternative or does some on the list has a small quantity they would sell to the team nick Cell 337 258 2527 Helping UL become a world Class Engineering and Educational School Disagree I Learn

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Re: [amsat-bb] CTCSS Sat Tone Operation
by Kevin M 01 Apr '18

01 Apr '18

> I have recently resurrected, for Easter, an ancient Kenwood TS-9500, a 435 MHz Sat radio. DOH! DOH! Okay... you would have been RECEIVING SO-50 with that radio, so not a problem... CTCSS won't matter a bit. BUT, what I said holds true for CTCSS tones on a 2m transmit radio for SO-50. It's late, my apologies. 73, Kevin N4UFO ------------------------------------------------------------------ > I suddenly realized that there was no CTCSS technology in this radio, but I could never tell while on air, on SO-50, AO-91, or AO-92, today! Hi Cee, I'm afraid despite your observation, it DOES matter on SO-50... it will not retransmit your signal without the tone. (unless it's while you are overriding someone else's signal) Please DO NOT transmit to SO-50 without a CTCSS tone of 67.0 Hz as you can and likely will CAUSE QRM. There are a number of terrestrial stations now (cross band repeaters, remote bases, etc.) that transmit on the SO-50 2m uplink without a tone and cause considerable QRM problems. Their strong signals 'collide' with stations trying to talk through SO-50 and it results in at most a squealing crash of signals, but more than likely nothing getting repeated at all. (Sometimes the 'dead air' on SO-50 is because of either this or because too many ops are trying to transmit at once... no one clearly gets through and the tone is not heard by the receiver; SO, it doesn't key up the downlink.) Without the tone, we cannot hear these QRMing stations when they 'transmit in the clear' in order to catch a callsign or a location. Just to be clear... this is the case with SO-50... AO-85, AO-91 and AO-92 are different. Thanks & 73, Kevin N4UFO

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Re: [amsat-bb] CTCSS Sat Tone Operation
by Kevin M 01 Apr '18

01 Apr '18

> I suddenly realized that there was no CTCSS technology in this radio, but I could never tell while on air, on SO-50, AO-91, or AO-92, today! Hi Cee, I'm afraid despite your observation, it DOES matter on SO-50... it will not retransmit your signal without the tone. (unless it's while you are overriding someone else's signal) Please DO NOT transmit to SO-50 without a CTCSS tone of 67.0 Hz as you can and likely will CAUSE QRM. There are a number of terrestrial stations now (cross band repeaters, remote bases, etc.) that transmit on the SO-50 2m uplink without a tone and cause considerable QRM problems. Their strong signals 'collide' with stations trying to talk through SO-50 and it results in at most a squealing crash of signals, but more than likely nothing getting repeated at all. (Sometimes the 'dead air' on SO-50 is because of either this or because too many ops are trying to transmit at once... no one clearly gets through and the tone is not heard by the receiver; SO, it doesn't key up the downlink.) Without the tone, we cannot hear these QRMing stations when they 'transmit in the clear' in order to catch a callsign or a location. Just to be clear... this is the case with SO-50... AO-85, AO-91 and AO-92 are different. Thanks & 73, Kevin N4UFO

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