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CX2SA > SATDIG 26.01.18 11:01l 794 Lines 28469 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: Chinese TY2-TY6 (Dani EA4GPZ)
2. Re: HT for sats (Paul Stoetzer)
3. Re: HT for sats (Patrick STODDARD (WD9EWK/VA7EWK))
4. Re: HT for sats (John Geiger)
5. Re: Exciting Coax (Greg D)
6. Re: AO-92 camera results (Robert McGwier)
7. Re: DM90 and DL98/DL99 on Saturday (Glenn Miller - AA5PK)
8. Looking to connect with other FT847 users on linear sats
(Brian Helm)
9. Re: DM90 and DL98/DL99 on Saturday (David Loftus)
10. ANS-026 AMSAT News Service Special Bulletin - AO-92
Commissioned, Open for Amateur Use (JoAnne Maenpaa)
11. Re: Keps accuracy (Ray Hoad)
12. Re: Looking to connect with other FT847 users on linear sats
(Brian Helm)
----------------------------------------------------------------------
Message: 1
Date: Thu, 25 Jan 2018 19:56:39 +0100
From: Dani EA4GPZ <daniel@????????.???>
To: amsat-bb@?????.???
Subject: Re: [amsat-bb] Chinese TY2-TY6
Message-ID: <b7144e9d-6fcc-ef2b-9b43-e096f4b9c284@????????.???>
Content-Type: text/plain; charset=utf-8
El 25/01/18 a las 18:49, Robert McGwier escribi?:
> These seem interesting with 5 MBPS OFDM downlink on 5.8 GHz.
>
>
> I'm wondering if there are sufficient details published to do an SDR?
>
> Bob
> N4HY
Hi Bob,
That would probably be hard. Most likely the 5GHz OFDM downlink only
works by request of the groundstation. Also, a OFDM is rather complex to
reverse engineer and such.
Let us first try to get some information from the team regarding the
70cm telemetry, since this transmits continuously and uses a much
simpler protocol (but we're still unable to do much).
In any case, anyone with the appropriate receiver can give it a go and
try to record the 5GHz downlink during a pass. If something shows up in
the recording, it would be interesting and I would surely give it a good
look.
73,
Dani.
------------------------------
Message: 2
Date: Thu, 25 Jan 2018 13:57:15 -0500
From: Paul Stoetzer <n8hm@????.???>
To: amsat-bb@??????.???
Cc: AMSAT BB <amsat-bb@?????.???>, James Sanford <k8zzu@?????????.???>
Subject: Re: [amsat-bb] HT for sats
Message-ID:
<CABzOSOosoy=xsEVnXmnxjgRRgtSNfkFu=BtCUoLd+GXM_d0HLg@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Patrick,
The DJ-G7T does appear to be unsuitable for full duplex U/v operation.
In limited testing (only 3 passes - 2 with a whip, 1 with an Elk), I
experienced desense. I could still hear my own signal a bit, but it
was not clear. I even keyed up with a whip on 1.2 GHz during a pass of
AO-92 when it was in high speed mode and the 1.2 GHz signal mostly
wiped out the satellite reception.
Even just listening, the receiver performs poorly for satellite operation.
That said, I have used the DJ-G7T as my transmitter to make contacts
on three passes of AO-92 in mode L/v.
73,
Paul, N8HM
On Thu, Jan 25, 2018 at 1:50 PM, Patrick STODDARD (WD9EWK/VA7EWK)
<amsat-bb@??????.???> wrote:
> John,
>
> "(O)n current HTs"? Other than some reports I have seen about
> the Alinco DJ-G7T and its poor receiver for FM satellites in
> general, it appears that the HTs that have been previously
> reported as capable of full-duplex operation with V/U FM
> satellites like AO-51 and SO-50 would be fine with the mode
> B (U/V) satellites like AO-91 and AO-92. With the uplink on
> 70cm, you avoid issues with harmonics which can be an issue
> on some radios capable of full-duplex operation when you
> transmit on 2m - keeping in mind that frequencies in the
> 435-438 MHz satellite subband can be very close to the third
> harmonic of the 2m uplink frequency.
>
> After AO-85's launch in October 2015, I tested a few Chinese-
> made 2m/70cm FM HTs that were advertised as being capable of
> full-duplex operation. None of them could work SO-50 full-
> duplex due to receiver desense, but could be used with AO-85.
> I wrote a series of AMSAT-BB posts about those tests at that
> time, and a link to a summary with other links to the specific
> models is in the AMSAT-BB archive:
>
> http://amsat.org/pipermail/amsat-bb/2015-December/056269.html
>
> I have been using the Wouxun KG-UV9D with AO-91 on a regular
> basis, either with my Elk log periodic or an MFJ-1717 2m/70cm
> long duckie. This radio, along with other HTs like my TH-D72
> and an old TH-D7 I had for a little bit, is capable of full-
> duplex operation with mode B (U/V) satellites. I have seen
> other reports online of hams using a Wouxun KG-UV8D (or one
> of its variants) to successfully work AO-91 full-duplex.
>
> 73!
>
>
>
>
> Patrick WD9EWK/VA7EWK
> http://www.wd9ewk.net/
> Twitter: @?????? or http://twitter.com/WD9EWK
>
>
>
>
>
>
> On Thu, Jan 25, 2018 at 6:30 PM, John Geiger <af5cc2@?????.???> wrote:
>>
>> Does desense on 2m occur with using Mode B FM satellites in full duplex on
>> other current HTs?
>>
>> 73 John AF5CC
>>
>
------------------------------
Message: 3
Date: Thu, 25 Jan 2018 19:09:45 +0000
From: "Patrick STODDARD (WD9EWK/VA7EWK)" <amsat-bb@??????.???>
To: Paul Stoetzer <n8hm@????.???>
Cc: AMSAT BB <amsat-bb@?????.???>, James Sanford <k8zzu@?????????.???>
Subject: Re: [amsat-bb] HT for sats
Message-ID:
<CAN6TEUeBBzwbQ0JKxVLn2nEPzgcf7VWTU5dPsoN0OYp3gP+UDA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Paul,
That's what I thought I saw about the DJ-G7T used recently.
Thanks for posting that confirmation.
I bought one in 2009 when they came out, and found it to be
a poor performer with AO-27, AO-51, and SO-50 back then. I
kept the HT, since it does have 1.2 GHz capability with 5
kHz tuning steps - a feature missing from most other 1.2 GHz
HTs. If/when I find my DJ-G7T in my garage, I was planning
to use it only as an uplink radio, and pair it up with another
radio for full-duplex operation.
Away from using it with FM satellites, its performance for
using local repeaters on any of its 3 bands is OK - including
an analog 1.2 GHz repeater we had in the Phoenix area back
in 2009. Not a great performer, but adequate with the stronger
signals from the local repeaters compared to FM satellites.
73!
Patrick WD9EWK/VA7EWK
http://www.wd9ewk.net/
Twitter: @?????? or http://twitter.com/WD9EWK
On Thu, Jan 25, 2018 at 6:57 PM, Paul Stoetzer <n8hm@????.???> wrote:
> Patrick,
>
> The DJ-G7T does appear to be unsuitable for full duplex U/v operation.
> In limited testing (only 3 passes - 2 with a whip, 1 with an Elk), I
> experienced desense. I could still hear my own signal a bit, but it
> was not clear. I even keyed up with a whip on 1.2 GHz during a pass of
> AO-92 when it was in high speed mode and the 1.2 GHz signal mostly
> wiped out the satellite reception.
>
> Even just listening, the receiver performs poorly for satellite operation.
>
> That said, I have used the DJ-G7T as my transmitter to make contacts
> on three passes of AO-92 in mode L/v.
>
> 73,
>
> Paul, N8HM
>
>
------------------------------
Message: 4
Date: Thu, 25 Jan 2018 13:15:34 -0600
From: John Geiger <af5cc2@?????.???>
To: amsat-bb@??????.???
Cc: AMSAT BB <amsat-bb@?????.???>, Paul Stoetzer <n8hm@????.???>,
James Sanford <k8zzu@?????????.???>
Subject: Re: [amsat-bb] HT for sats
Message-ID:
<CAHC1P28qnOwG7LoO54=Y675cAPMfY6i+o8RAmynPyaxiSQ1LEA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
I have used a Baofeng HT on the downlink on SO50 to get around the birdie
issue with my TS2000. It denses enough that I cannot hear myself on the
downlink. I now use a FT100D for the downlink on SO50 and that receives it
fine.
73 John AF5CC
On Thu, Jan 25, 2018 at 12:50 PM, Patrick STODDARD (WD9EWK/VA7EWK) <
amsat-bb@??????.???> wrote:
> John,
>
> "(O)n current HTs"? Other than some reports I have seen about
> the Alinco DJ-G7T and its poor receiver for FM satellites in
> general, it appears that the HTs that have been previously
> reported as capable of full-duplex operation with V/U FM
> satellites like AO-51 and SO-50 would be fine with the mode
> B (U/V) satellites like AO-91 and AO-92. With the uplink on
> 70cm, you avoid issues with harmonics which can be an issue
> on some radios capable of full-duplex operation when you
> transmit on 2m - keeping in mind that frequencies in the
> 435-438 MHz satellite subband can be very close to the third
> harmonic of the 2m uplink frequency.
>
> After AO-85's launch in October 2015, I tested a few Chinese-
> made 2m/70cm FM HTs that were advertised as being capable of
> full-duplex operation. None of them could work SO-50 full-
> duplex due to receiver desense, but could be used with AO-85.
> I wrote a series of AMSAT-BB posts about those tests at that
> time, and a link to a summary with other links to the specific
> models is in the AMSAT-BB archive:
>
> http://amsat.org/pipermail/amsat-bb/2015-December/056269.html
>
> I have been using the Wouxun KG-UV9D with AO-91 on a regular
> basis, either with my Elk log periodic or an MFJ-1717 2m/70cm
> long duckie. This radio, along with other HTs like my TH-D72
> and an old TH-D7 I had for a little bit, is capable of full-
> duplex operation with mode B (U/V) satellites. I have seen
> other reports online of hams using a Wouxun KG-UV8D (or one
> of its variants) to successfully work AO-91 full-duplex.
>
> 73!
>
>
>
>
> Patrick WD9EWK/VA7EWK
> http://www.wd9ewk.net/
> Twitter: @?????? or http://twitter.com/WD9EWK
>
>
>
>
>
>
> On Thu, Jan 25, 2018 at 6:30 PM, John Geiger <af5cc2@?????.???> wrote:
>
>> Does desense on 2m occur with using Mode B FM satellites in full duplex on
>> other current HTs?
>>
>> 73 John AF5CC
>>
>>
>
------------------------------
Message: 5
Date: Thu, 25 Jan 2018 11:18:35 -0800
From: Greg D <ko6th.greg@?????.???>
To: Edward R Cole <kl7uw@?????????.???>
Cc: AMSAT-BB@?????.???
Subject: Re: [amsat-bb] Exciting Coax
Message-ID: <f763ef27-b887-5ef9-c224-041908337896@?????.???>
Content-Type: text/plain; charset=ISO-8859-1
...and is exactly why I have never been successful at EME or much with
longer-distance weak signal stuff. Nice work, Ed!
Fortunately, most satellite work is not considered weak signal, so I can
be a bit more frugal with the coax and still be successful in making
contacts. But, yes, I really should tighten things up a bit when I get
the chance. I honestly put up with sucking water out of the the wet
9913 years ago way too long before landing the hardline. Life's too
short for bad coax.
Greg KO6TH
Edward R Cole wrote:
> I guess I differ with Greg KO6TH on what I consider "reasonable
> loss". I do a lot of VHF thru mw frequencies and hate to loose more
> than 1-dB in loss. I consider 25-foot of RG-213 at 144-MHz as max,
> then go to LMR-400 for longer runs (up to 150-foot). If longer runs
> needed then I use LDF or equivalent hardline.
>
> My 2m eme antennas are 214 foot from the PA and measured total loss is
> 1.67 dB, but my preamps are mounted on the tower and only see about
> 0.4 dB loss. On 1296 my dish is about 100-foot from the shack and I
> have 6-dB loss in the LMR-600 transmission line. Fortunately my high
> power PA's are located at the dish and only need 2w drive from my 20w
> transverter in the shack. On 1296 receive the preamp is mounted
> directly to the dish feed and have about 125 foot of LMR-400 to
> transverter (7-dB loss). But preamp has 37-dB gain so easily
> overcomes the loss with about 30-dB residual gain to the transverter
> to result in 0.3 dBNF. This is all for eme where losses will kill
> your ability so see weak signals.
>
> 73, Ed - KL7UW
> http://www.kl7uw.com
> Dubus-NA Business mail:
> dubususa@?????.???
> _______________________________________________
> Sent via AMSAT-BB@?????.???. 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
------------------------------
Message: 6
Date: Thu, 25 Jan 2018 14:38:25 -0500
From: Robert McGwier <rwmcgwier@?????.???>
To: Zach Leffke <zleffke@??.???>
Cc: amsat bb <amsat-bb@?????.???>
Subject: Re: [amsat-bb] AO-92 camera results
Message-ID:
<CA+K5gzd5iyfATKLMCeppxKCnyLc093FZ5Jk5VPaQz=O8+607ew@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
What he said
On Tue, Jan 16, 2018 at 4:18 PM, Zach Leffke <zleffke@??.???> wrote:
> In an attempt to behave differently than I normally do...I'll try to keep
> this one short.
>
> Quick warning....I'm speaking personally here, not on behalf of VT or
> anything, though I know there are many that share my sentiments here.
>
> This entire experience would not have been possible without AMSAT and the
> Amateur Radio community. And I don't just mean the obviously awesome folks
> that are on the Engineering team and the Operations team that have helped
> us so much along the way. I also mean everyone out there collecting
> telemetry and forwarding to the server. We wouldn't have made it without
> the entire community backing us up, and we recognize that!
>
> So for all of AMSAT and everyone else, HUGE thank you from VT. I hope the
> partnership continues for as long as possible with as many missions as
> possible.
>
>
> Thanks again!
>
> Zach, KJ4QLP
>
> Research Associate
> Aerospace Systems Lab
> Ted & Karyn Hume Center for National Security & Technology
> Virginia Polytechnic Institute & State University
> Work Phone: 540-231-4174
> Cell Phone: 540-808-6305
>
>
> On 1/16/2018 12:34 PM, Andrew Glasbrenner wrote:
>
>>
>> For those that have not been following AMSAT on Twitter or Facebook, we
>> have
>> done a few camera runs with AO-92 with very good results. A pass this
>> morning yielded 4 good images, two of which I have located their position
>> on
>> the ground. The images can be seen at
>> http://www.amsat.org/tlm/fox1d/images/index1.html
>>
>>
>> Some side by side comparisons with Google Earth and NOAA images can be
>> found
>> at: https://twitter.com/AMSAT/status/953294176933896195 and
>> https://twitter.com/AMSAT/status/953304248162406401 .
>>
>>
>> Congratulations again to Virginia Tech, and thanks for providing the
>> camera
>> experiments for AO-92 and Fox-1Cliff!
>>
>>
>> 73, Drew KO4MA
>>
>> AMSAT VP Operations
>>
>> _______________________________________________
>> Sent via AMSAT-BB@?????.???. 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@?????.???. 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
>
--
Bob McGwier
Founder, Federated Wireless, Inc
Founder and Technical Advisor, HawkEye 360, Inc
Research Professor Virginia Tech
Chief Scientist: The Ted and Karyn Hume Center for National Security and
Technology
Senior Member IEEE, Facebook: N4HYBob, ARS: N4HY
Faculty Advisor Virginia Tech Amateur Radio Assn, Trustee K4KDJ
Director of AMSAT
Member of PVRC (Roanoke-Blacksburg), TAPR, life member of ARRL and AMSAT,
NRVR.ORG (Rocketry)
------------------------------
Message: 7
Date: Thu, 25 Jan 2018 13:43:29 -0600
From: "Glenn Miller - AA5PK" <aa5pk@??????????.???>
To: "AMSAT BBS" <amsat-bb@?????.???>
Cc: k5ix@????.???
Subject: Re: [amsat-bb] DM90 and DL98/DL99 on Saturday
Message-ID: <D8E338088B414E06A455EB7822D1EED1@???????>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response
> Also the 1727Z SO-50 pass probably from DL99.
Correction to my plan. The 1727Z pass of SO-50 will be less than 1 degree,
so will skip that one.
May try the 1712Z AO-85 pass instead.
Glenn
------------------------------
Message: 8
Date: Thu, 25 Jan 2018 13:27:06 -0600
From: Brian Helm <helmet.head22@?????.???>
To: amsat-bb@?????.???
Subject: [amsat-bb] Looking to connect with other FT847 users on
linear sats
Message-ID: <6A724D9C-5BE3-48A7-B36B-F6880B6DE974@?????.???>
Content-Type: text/plain; charset=us-ascii
Looking to connect with other FT847 users on linear sats.
I'm new to this rig and wanted to share information and learn.
Brian AA9KG
------------------------------
Message: 9
Date: Thu, 25 Jan 2018 15:15:10 -0600
From: David Loftus <ukepilot@?????.???>
To: Glenn Miller - AA5PK <aa5pk@??????????.???>
Cc: AMSAT BBS <amsat-bb@?????.???>, k5ix@????.???
Subject: Re: [amsat-bb] DM90 and DL98/DL99 on Saturday
Message-ID: <73E6C2C5-DE12-42E9-97A8-A42DD99641E8@?????.???>
Content-Type: text/plain; charset=utf-8
As far as I?m concerned, this is the DXpedition of the year. Thanks for
roving to my home grid so I can FINALLY work DL99!
On Jan 25, 2018, at 1:43 PM, Glenn Miller - AA5PK <aa5pk@??????????.???>
wrote:
>> Also the 1727Z SO-50 pass probably from DL99.
>
> Correction to my plan. The 1727Z pass of SO-50 will be less than 1
degree, so will skip that one.
> May try the 1712Z AO-85 pass instead.
> Glenn
>
>
>
------------------------------
Message: 10
Date: Thu, 25 Jan 2018 21:42:38 -0600
From: "JoAnne Maenpaa" <k9jkm@???????.???>
To: "'amsat bb'" <amsat-bb@?????.???>
Subject: [amsat-bb] ANS-026 AMSAT News Service Special Bulletin -
AO-92 Commissioned, Open for Amateur Use
Message-ID: <005801d39657$b6007200$22015600$@???>
Content-Type: text/plain; charset="iso-8859-1"
AMSAT NEWS SERVICE SPECIAL BULLETIN
ANS-026
In this Special Bulletin Edition:
* AO-92 Commissioned, Open for Amateur Use
* AMSAT Membership Deal and Getting Started
SB SAT @ AMSAT $ANS-026.01
ANS-026 AMSAT News Service Special Bulletin
AMSAT News Service Bulletin 026.01
>From AMSAT HQ KENSINGTON, MD.
DATE January 26, 2018
To All RADIO AMATEURS
BID: $ANS-026.01
AO-92 Commissioned, Open for Amateur Use
On the 03:25 UTC pass on January 26, 2018, AMSAT Vice President ?
Engineering Jerry Buxton, N0JY, announced that AO-92 had been
commissioned and formally turned the satellite over to AMSAT
Operations. AMSAT Vice President ? Operations Drew Glasbrenner, KO4MA,
then declared that AO-92 was now open for amateur use.
Initially, the U/v FM transponder will be open continuously for a
period of one week. After the first week, operations will be scheduled
between the U/v FM transponder, L-Band Downshifter, Virginia Tech
Camera, and the University of Iowa?s High Energy Radiation CubeSat
Instrument (HERCI).
Schedule updates will appear in the AMSAT News Service Weekly
Bulletins and will also be posted to the AMSAT-BB, AMSAT?s Twitter
account (@??????? the AMSAT North America Facebook group, and the
AMSAT website at https://www.amsat.org/satellite-schedules/
AO-92 was launched on the PSLV-C40 mission from Satish Dhawan Space
Centre in Sriharikota, India on January 12, 2018. For the past two
weeks, the AMSAT Engineering and Operations teams have been testing
the various modes and experiments on board. Testing has shown that
both the U/v FM transponder and L-Band Downshifter work very well. The
Virginia Tech camera has returned stunning photos and data from HERCI
has been successfully downlinked.
AMSAT thanks the 178 stations worldwide that have used FoxTelem to
collect telemetry and experiment data from AO-92 during the
commissioning process. The collection of this data is crucial to the
missions of AMSAT?s Fox-1 satellites. Please continue to collect data
from AO-85, AO-91, and AO-92.
RADIO PROGRAMMING CHART
Fox-1D Doppler Shift Correction
Memory 1 (AOS) - TX 435.340 MHz (67.0 Hz Tone), RX 145.880 MHz
Memory 2 (Rise) - TX 435.345 MHz (67.0 Hz Tone), RX 145.880 MHz
Memory 3 (TCA) - TX 435.350 MHz (67.0 Hz Tone), RX 145.880 MHz
Memory 4 (Descend) - TX 435.355 MHz (67.0 Hz Tone), RX 145.880 MHz
Memory 5 (LOS) - TX 435.360 MHz (67.0 Hz Tone), RX 145.880 MHz
The L-band experiment will use 1267.350 MHz uplink with 145.880 MHz
downlink. UHF and L-band uplink operation are set by the command
stations; the operating schedule will be posted.
[ANS thanks AMSAT Vice-President Engineering, Jerry Buxton, N?JY,
AMSAT Vice President Operatings Drew Glasbrenner, KO4MA, and AMSAT
Executive Vice President Paul Stoetzer, N8HM for the above information]
---------------------------------------------------------------------
AMSAT Membership Deal and Getting Started
AMSAT membership supports the organization and construction of new
satellites. Right now, we are offering a free PDF copy of our Getting
Started with Amateur Satellites with every new on-line membership.
This is -the- primer for getting on the sats, and is updated every
year. See https://www.amsat.org/product-category/amsat-membership/
AMSAT also sells both the popular Arrow Antenna satellite models and
the M2 LEOpack antennas. Sales also benefit AMSAT projects.
https://www.amsat.org/product-category/hardware/
[ANS thanks AMSAT Office for the above information]
---------------------------------------------------------------------
In addition to regular membership, AMSAT offers membership in the
President's Club. Members of the President's Club, as sustaining
donors to AMSAT Project Funds, will be eligible to receive addi-
tional benefits. Application forms are available from the AMSAT
Office.
Primary and secondary school students are eligible for membership
at one-half the standard yearly rate. Post-secondary school students
enrolled in at least half time status shall be eligible for the stu-
dent rate for a maximum of 6 post-secondary years in this status.
Contact Martha at the AMSAT Office for additional student membership
information.
73,
This week's ANS Editor,
JoAnne Maenpaa, K9JKM
k9jkm at amsat dot org
------------------------------
Message: 11
Date: Thu, 25 Jan 2018 22:00:42 -0600
From: "Ray Hoad" <ray.hoad@????????.???>
To: "'Dale Kubichek'" <N6JSX@?????.???>, <amsat-bb@?????.???>
Subject: Re: [amsat-bb] Keps accuracy
Message-ID: <003f01d3965a$3cad4dd0$b607e970$@????????.???>
Content-Type: text/plain; charset="UTF-8"
Thank you Dale for your comments. Good questions. I will try to answer them.
I think part of the confusion described may be the result of just the
process of launching a new amateur CubeSat with other CubeSats. CubeSats in
the 1U format (4 x 4 inch) are launched in groups of typically 3 objects.
Unavoidably, the placing in orbit of a new CubeSat is followed by the
process of determining which object in a "flock" of CubeSats is the
satellite in which you are interested. This is a usually relatively short (5
to 10 day) period of tracking a group of CubeSats until they separate enough
to isolate the one of interest. A spectrum analyzer program is used to
identify which object is our satellite.
Also a set of "PRE-Launch" TLEs (that is calculation based on the EXPECTED
orbit at launch) are usually produced by the launching entity. The
"PRE-Launch" TLEs are used until POST-Launch TLEs (for the group of objects
that your satellite is in) are released from the Space-Track website. The
POST-Launch TLEs released from Space-Track are determined by tracking
sensors of the U.S. Air Force.
Finally, your satellite and its associated TLEs are determined and we settle
down to an single, accurate, reliable set of TLEs ... and all the other
"best guesses" go away. (Although they may be still floating around on the
internet.) But, there are so many variables (did you launch on time, did
you get released on time, has the group your CubeSat is in separated enough
to identify your satellite, etc.) that the process that can be both
confusing and annoying at the same time. Remember, we did not pay for this
ride and it took a lot of work to get our University sponsor and us on that
rocket. In spite of all the hassle, it is still very much worth the effort.
The source for AMSAT-NA TLEs (or KEPS) is from the Space-Track website
(www.space-track.org). This is the most reliable and the most accurate
primary data (not filtered through another website) available on a
continuing basis. This data is used to keep track of the cloud of objects
that circle our Earth, so accuracy is a major concern for Space-Track.
Anyone who has watched the International Space Station (ISS) suddenly appear
sunlit in a dark sky (right on time and in the predicted place) knows how
accurate these TLEs are.
TLE data is updated on a continual basis and that depends on when the object
is available to the Air Force tracking sensors. Most objects cannot change
their orbits and have orbits that do not change radically over a seven day
period. Thus weekly updates are completely adequate with one exception. The
ISS is an example of an object that has the ability to change its orbit.
Thus the TLEs for the ISS are updated more frequently.
The weekly AMSAT-NA TLE distribution is updated every Thursday evening (CST)
and is available from the AMSAT website www.amsat.org under the dropdown
menu <Satellite Info>, <Keplerian Elements Resources>. Look under "Current
Bulletins" and click the blue HyperText "NASA (2-line) format elements".
You can have an email with these TLE's send to you every Thursday evening by
signing up for the KEPS mailing list. Under the same heading "Current
Bulletins", click on the blue HyperText "Keps mailing list". Go down to the
heading "Subscribing to Keps" and follow the instructions to sign up.
You can also get a TLE element set with the ISS TLEs updated at least twice
a day by going to the "Keplerian Elements Resources" website page as
discussed above and under the heading "Current Bulletins" click on the blue
HyperText "NASA (2-line) stripped of headers". This TLE data on the ISS is
updated based data from NASA's Johnson Space Flight Center.
Ray Hoad
WA5QGD
Orbital Elements Manager
I see all these (hard to follow) AMSAT-BB postings about Keps implying there
is NO ONE site that has accurate Keps. That we need to get this from here or
that from there and combine to make a KEP.TLE for our programs.
Is there no HAM SAT Keps that are complete & accurate?
I was under the impression the AMSAT Keps were the most accurate for HAM
SATs? Is that true or not, and if not, WHY?
AMSAT Keps - when are they updated? If daily - what time?
How often should Users update their program Keps?
I
Dale Kubichek, MS-EET, N6JSX
http://groups.yahoo.com/group/HAM-SATs
http://groups.yahoo.com/group/RDF-USA
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Sent via AMSAT-BB@?????.???. 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
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Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 12
Date: Thu, 25 Jan 2018 18:54:10 -0600
From: Brian Helm <helmet.head22@?????.???>
To: amsat-bb@?????.???
Subject: Re: [amsat-bb] Looking to connect with other FT847 users on
linear sats
Message-ID: <626506DA-C3D7-41B1-9BBA-C46EA3C565EA@?????.???>
Content-Type: text/plain; charset=us-ascii
> I can see how my sentence was confusing...sorry
>
> I'm trying to find other people who use the FT 847 for making contacts on
the linear satellites. Not to discuss while on the air, but to connect
through email or phone or whatever to talk to them about the 847 quirks and
settings and possible improvements.
------------------------------
Subject: Digest Footer
_______________________________________________
Sent via amsat-bb@?????.???.
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 member? Join now to support the amateur satellite program!
http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
End of AMSAT-BB Digest, Vol 13, Issue 40
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