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CX2SA > SATDIG 07.07.08 00:00l 1120 Lines 41347 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: NASA's American Student Moon Orbiter... (D. Mynatt)
2. ANS-188 AMSAT News Service Weekly Bulletins (JoAnne Maenpaa)
3. TR-751 (Szegedy)
4. Fw: Re: NASA's American Student Moon Orbiter... (i8cvs)
5. Re: Fw: Re: NASA's American Student Moon Orbiter...
(John B. Stephensen)
6. AO-51 L-Band Packet Uplink (Rob Hardenberg PE1ITR)
7. Re: AO-51 L-Band Packet Uplink (Gould Smith)
8. Free Items-you pick up (Charles Pennington)
9. Re: AO-51 L-Band Packet Uplink (Edward Cole)
----------------------------------------------------------------------
Message: 1
Date: Sat, 5 Jul 2008 13:48:08 -0600
From: "D. Mynatt" <dave(AT)mynatt.biz>
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
To: "i8cvs" <domenico.i8cvs(AT)tin.it>, "Bob Bruninga"
<bruninga(AT)usna.edu>, "'Joe'" <nss(AT)mwt.net>, "'Edward Cole'"
<kl7uw(AT)acsalaska.net>
Cc: 'AMSAT-BB' <amsat-bb(AT)amsat.org>, 'G0MRF David Bowman'
<g0mrf(AT)aol.com>
Message-ID: <7DA11CFF0EFE4683900E2C3B01990E6C(AT)compaq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Neat stuff to be sure and I appreciate the math. So, as I understand it from
my limited knowledge, is that once we know the frequencies up and down, then
designing the ground station antenna will be easier. My sense is that a 3m
dish, with the right slewing and control will be able to *hear* the orbiter
at it's closest point to earth without experiencing too many dropouts.
CW with a BW of 500Hz appears to be the mode of choice -that seems
reasonable to me, as does PSK- and the craft won't be in peril power-wise to
do that.
I still don't understand, albeit from a novice viewpoint, why the craft and
the radio system can't be tethered making it two separate units in a way.
The craft can angle for it's purpose and so can the radio. Is that possible,
given the state of craftsmanship or art we have?
Dave
----- Original Message -----
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
To: "Bob Bruninga" <bruninga(AT)usna.edu>; "'Joe'" <nss(AT)mwt.net>; "'Edward
Cole'" <kl7uw(AT)acsalaska.net>
Cc: "'AMSAT-BB'" <amsat-bb(AT)amsat.org>; "'G0MRF David Bowman'"
<g0mrf(AT)aol.com>
Sent: Saturday, July 05, 2008 11:20 AM
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> ----- Original Message -----
> From: "Robert Bruninga" <bruninga(AT)usna.edu>
> To: "'Joe'" <nss(AT)mwt.net>; "'Edward Cole'" <kl7uw(AT)acsalaska.net>
> Cc: "'AMSAT-BB'" <amsat-bb(AT)amsat.org>; "'G0MRF David Bowman'"
> <g0mrf(AT)aol.com>
> Sent: Saturday, July 05, 2008 4:09 AM
> Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
>
>> > The whole part that is confusing me on all this power
>> > budget stuff is the to me, the seemingly HIGH budget.
>> > I've done moon bounce. And many of these
>> > numbers seem to be not too far from Moonbounce
>> > numbers, and that is a horrid dead piece of rock
>> > reflector. that has a efficiency of a wet sponge.
>> > ...And it only reflects 6% of the energy it gets.
>>
>> My guess is ... That 6% is an awful lot of power considering the
>> 3.6 million square miles of surface doing the reflecting.
>> Conversly, any amateur transmitter at the moon would have a much
>> smaller receiving/transmitting antenna. Though lots more
>> concentrated power.
>>
>> So what you gain in changing from a 1/R^4 to a 1/R^2 path loss
>> you lose a lot of it in the loss of signal receive aperture. Or
>> something like that maybe.
>>
>> Bob, WB4APR
>>
>> > but i would think anything there that is active
>> > circutry is a thousand times more efficient at
>> > sendinga signal back as compared to the moons
>> > surface.
>> > or what am I missing?
>
>> >Joe
>
> Hi Bob, WB4APR
>
> Your guess is.......absolutely correct.
>
> I also did 432 MHz EME from 1977 to 1980 and I will try to demonstrate
> in more datails to Joe that your analysis hit the centre of his question.
>
> Hi Joe
>
> Suppose to be in the center of a sphere with radius of 380.000 km that is
> the average distance from the earth to the moon.
>
> The internal surface S of the above sphere computed in square meters is:
>
> 6 2 18
> S= 4 x 3,14 x ( 380 x 10 ) = 1,81 x 10 square meters
>
>
> Suppose now to have in your hand an isotropic antenna radiating all around
> and uniformly the power P = 1 watt at 432 MHz
>
> As soon the wave has reached the internal surface of the above sphere the
> full power of 1 watt will be collected on it so that the power density D
> collected in each square meter is:
>
> 1 -19
> D = ------------------------ = 5,52 x 10 watt / square meter
> 18
> 1,81 x 10
>
> But in one point of the above sphere there is the disc of the moon which
> radius is 1735 km =1735000 meters and so the surface S1 of the lunar
> disc is:
> 2 12
> S1 = 1735000 x 3,14= 9,45 x 10 square meters
>
> The full power density P1 collected over the disc of the lunar surface
> will
> be D x S1 and so
>
> -19 12
> P1= 5,52 x 10 x 9,45 x 10 = 0,0000052164 watt
>
> Only the 7% of P1 at 432 MHz is reflected back by the lunar surface
> and very important the reflected power P2 is reirradiated and scattered
> back "isotropically" by the lunar disc and so the reflected power is
>
> P2=(0,0000052164 / 100) x 7= 0,0000003651 watt
>
> Now P2 make another trip of 380.000 km from the moon to the earth
> but actually the power P3 collected by each square meter over the earth
> surface will be only:
>
> 0,0000003651 -25
> P3= ----------------------- = 2,017 x 10 watt / square meter
> 18
> 1,81 x 10
>
> Since we have in our hand an isotropic antenna at 432 MHz originally
> radiating 1 watt we want to know what actually is the power Pr received
> back from the moon into the same isotropic antenna.
>
> The aperture area A of an isotropic antenna at 432 MHz i.e. at a
> wavelenght
> of 0,6944 meters is:
>
> / 2 2
> /\ 0,6944
> A = -------- = ----------- = 0,0383 square meters
> 4 x 3,14 4 x 3,14
>
> It follow that the power Pr received by the isotropic antenna on the earth
> is Pr = P3 x A and so
>
> -25 -27
> Pr= 2,017 x 10 x 0,0383 = 7,725 x 10 watt
>
> Consequently the round trip isotropic attenuation (Att) earth-moon-earth
> for
> 380.000 km at 432 MHz off the moon is P / Pr and so in dB
>
> 1
> (Att) = 10 log ------------------- = 261 dB
> 10 -27
> 7,725 x 10
>
> The average of 432 MHz EME active stations are using the following:
>
> Antenna gain = 30 dBi
> Power at the antenna feed = 1000 watt
> Overall RX noise figure NF= 0.6 dB = 43 kelvin
> BW for CW = 500 Hz
> Equivalent antenna temperature Ta when pointed at the cold-sky = 50 kelvin
>
> With the above data NF, BW and Ta the noise floor of the receiving system
> KTB = -182 dBW or -152 dBm
>
> Link budged calculation 432 MHz:
>
> TX power at the feed.............................+30 dBW
> TX Antenna gain....................................+30 dBi
> --------------
> Transmitted EIRP toward the moon.....+60 dBW = 1 Megawatt
> Round trip attenuation 380.000 km.. - 261 dB
> --------------
> Received power Pr on isotropic
> antenna at the earth .............................-201 dBW
> RX antenna gain................................. +30 dB
> --------------
> -
> Available power at RX input............. - 171 dBW
> RX noise floor.....................................- 182 dBW
> --------------
>
> CW signal received with a S/N ratio + 11 dB
>
> To get a S/N ratio of 11 dB off the moon on CW it was necessary to
> 6
> transmit + 60 dBW = 10 watt = 1 Megawatt toward the moon but
> calculating the round trip attenuation we remember that transmitting
> isotropically 1 watt from the earth the power collected by the lunar
> disc was
>
> P1= 0,0000052164 watt
> 6
> If now we multiply P1 by 10 we get the full power Pc collected by the
> lunar disc while transmitting on CW toward the moon and so:
> 6
> Pc = 0,0000052164 x 10 = 5.21 watt ( an awful lot of power as Bob said)
>
> Only the 7% of Pc at 432 MHz is reflected back by the lunar surface
> and very important the reflected power P is reirradiated and scattered
> back "isotropically" by the lunar disc and so the reflected power is
>
> P = ( 5.21 / 100) x 7= 0, 3651 watt
>
> If I want to receive a CW signal of 0,3651 watt transmitted isotropically
> from the moon and if I want to receive it with a S/N ratio of 11 dB it is
> evident that I need a 30 dBi antenna gain and a receiving system with
> a noise floor of - 182 dBW.........no way !
>
> If instead I want to receive a SSB or CW signal transmitted in 2 meters
> by a satellite or from the moon with a power of 10 watt feed into a 10 dBi
> antenna gain and using a 2 meters ground station antenna with gain of only
> 13 dBi and a receiving system with a noise floor of - 178 dBW then
> everyting in SSB and CW becomes very easy as calculation shows.
>
> 2 meters downlink budged calculation:
>
> Satellite power ................................... + 10 dBW
> Satellite antenna gain.......................... + 10 dBi
> --------------
> Satellite EIRP..................................... + 20 dBW (100 W EIRP)
> 2 m isotr. attenuation 400.000 km.. -188 dB
> --------------
> power density received on a ground
> isotropic 2 meters antenna..................-168 dBW
>
> 2 m ground station antenna gain.........+ 13 dBi
> ---------------
> Power density at 2 m RX input...........- 155 dBW
> 2 m receiver noise floor......................- 178 dBW
> ---------------
> -
> Received CW signal S/N.................... + 23 dB
>
> If we increase the BW to 2500 Hz for a SSB QSO than the noise floor
> of the receiving system increases by 10 log (2500/500) = 7 dB i.e.
> 10
> it becames about -171 dB and the SSB signal will be received with a
> S/N ratio = 23-7 = 16 dB wich is a very strong SSB signal.
>
> Be aware that the above figures are based on the assumption that the
> satellite antennas are pointig toward the earth wich is not the case with
> a moon orbiting satellite.
>
> In addition we assume that the station in QSO with you has a 70 cm
> EIRP capability in order to get 10 watt from the 2m transponder only
> for you.
>
> On the other side if a fixed 10 dBi 2 meters antenna is placed over the
> moon and it is oriented toward the earth could easily cover the
> inclination
> X libration window without any adjustement and only from the point of
> view of the downlink with 10 watt it can be easily used for a transponder
> on the moon.
>
> If you make again the downlink budged calculation considering that
> the 2 meter transponder will develope only 2.5 watt for you then you
> will realize that the transponder will accomodate 3 more stations if each
> one is getting 2.5 watt as well.
> In this case your S/N ratio will be still +15.5 dB on CW and +8.5 dB
> in SSB and the same is true for the other 3 users.
>
> I hope this helps
>
> 73" de
>
> i8CVS Domenico
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Sent via AMSAT-BB(AT)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
>
------------------------------
Message: 2
Date: Sat, 5 Jul 2008 21:03:30 -0500
From: "JoAnne Maenpaa" <k9jkm(AT)comcast.net>
Subject: [amsat-bb] ANS-188 AMSAT News Service Weekly Bulletins
To: "'amsat-bb'" <amsat-bb(AT)amsat.org>
Message-ID: <002c01c8df0c$7e20f5b0$7a62e110$(AT)net>
Content-Type: text/plain; charset="iso-8859-1"
AMSAT NEWS SERVICE
ANS-188
ANS is a free, weekly, news and information service of AMSAT North
America, The Radio Amateur Satellite Corporation. ANS reports on the
activities of a worldwide group of Amateur Radio operators who share an
active interest in designing, building, launching and communicating
through analog and digital Amateur Radio satellites.
Please send any amateur satellite news or reports to:
ans-editor(AT)amsat.org
***************************************************************
*** 2008 AMSAT Space Symposium and Annual General Meeting ***
*** October 24-26 in Atlanta, Georgia ***
*** http://www.amsat.org/amsat-new/symposium/2008/index.php ***
***************************************************************
In this edition:
* P3E Update From Friedrichshafen Ham Radio 2008
* AMSAT Field Day Logs Are Due by July 14
* New Earth Photos Received From Cute-1.7
* AMSAT 2008 Space Symposium Call For Papers
* ARISS Status Report for the Week of June 30, 2008
SB SAT (AT) AMSAT $ANS-188.01
P3E Update From Friedrichshafen Ham Radio 2008
AMSAT News Service Bulletin 188.01
>From AMSAT HQ SILVER SPRING, MD.
July 6, 2008
To All RADIO AMATEURS
BID: $ANS-188.01
AMSAT-DL provided P3E updates at the HAM RADIO 2008 Convention - the
international amateur radio exhibition held June 27-29 in Friedrich-
shafen near Lake Constance in Germany.
This year HAM RADIO was focused on the topic "Satellites and Space
Activities in Hamradio", giving AMSAT-DL, in cooperation with DARC,
an opportunity to offer a special show highlighting amateur radio in
space. This included flight hardware at the AMSAT-DL booth.
Peter G?lzow, DB2OS, AMSAT-DL gave a presentation discussing the
current status of activities for the construction and launch of the
new satellite AMSAT P3-E. The P3E team reported that the mechanical
work on the satellite has been completed but it doesn't yet have the
Internal Housekeeping Unit (IHU). There has been good progress on the
transponder payloads with the 435 to 145 MHz software defined linear
transponder (SDX) being demonstrated at the event by Howard, G6LVB.
Peter reported that the cost quoted by Arianespace for the launch of
P3E is beyond the budget of AMSAT-DL, however, AMSAT-F has offered
its support in any further negotiations. The possibility of using
launch sites operated by India, Russia or Japan is being investigated.
Dr. Achim Vollhardt, DH2VA, AMSAT-DL spoke on the status of the inter-
planetary Mars mission AMSAT P5-A. P3E is closely linked to the P5E
Mars Orbiter also being built by AMSAT-DL. This will be the first pri-
vate venture spacecraft to go to Mars and will use the 2.4 GHz and 10 GHz
Amateur Satellite Service frequency allocations.
The exhibition also included live reception of interplanetary space
probes by Freddy de Guchteneire, ON6UG. Professor Dr. Karl Meinzer,
DJ4ZC gave the opening address. Thilo Kootz, DL9KCE moderated a panel
discussion, "Amateur radio satellite - Where have they gone?", with
key participation by AMSAT-DL officers.
The new SDX (Software Defined Transponder) for P3E, was available for
live experimentation at the booth and throughout the fairgrounds
during the exhibition.
[ANS thanks Peter G?lzow, DB2OS, AMSAT-DL, and the news service at
the Southgate Amateur Radio Club for the above information]
/EX
SB SAT (AT) AMSAT $ANS-188.02
AMSAT Field Day Logs Are Due by July 14
AMSAT News Service Bulletin 188.02
>From AMSAT HQ SILVER SPRING, MD.
July 6, 2008
To All RADIO AMATEURS
BID: $ANS-188.02
AMSAT Director of Contests and Awards Bruce Paige, KK5DO, says,
"Now that Field Day is over for 2008, there is one more thing that
you have to take care of. You still need to submit your contacts
for scoring under the AMSAT rules."
You can download the rules from:
http://www.amsatnet.com/2008fd.pdf -or-
http://www.amsatnet.com/2008fd.doc
Bruce reminds participants that the Satellite Summary Sheet should
be used for submission of the AMSAT Field Day competition and be re-
ceived by KK5DO (email or postal mail) by 11:59 P.M. CDT, Monday,
July 14, 2008. The preferred method for submitting your log is via
e-mail to kk5do(AT)amsat.org or kk5do(AT)arrl.net.
You may also use the postal service but give plenty of time for your
results to arrive by the submission date. Add photographs or other
interesting information so that can be used an article for the Journal.
You will receive an email back (within one or two days) from Bruce
when he receives your email submission. If you do not receive a con-
firmation message, try sending it again or send it to his other e-mail
address.
If you are mailing your submission, the address is:
Bruce Paige, KK5DO
Director of Awards and Contests
PO Box 310
Alief, TX 77411-0310
[ANS thanks Bruce Paige, KK5DO for the above information]
/EX
SB SAT (AT) AMSAT $ANS-188.03
New Earth Photos Received From Cute-1.7
AMSAT News Service Bulletin 188.03
>From AMSAT HQ SILVER SPRING, MD.
July 6, 2008
To All RADIO AMATEURS
BID: $ANS-188.03
Mineo Wakita, JE9PEL reported this week that more pictures have been
received from the CMOS camera aboard the Cute-1.7 + APD II satellite.
The pictures may be viewed on-line at:
http://lss.mes.titech.ac.jp/ssp/cute1.7/blog/01-04.jpg
http://www.ne.jp/asahi/hamradio/je9pel/cut17ap2.htm
The CMOS camera aboard Cute-1.7 + APD II is controlled by a PDA which
also performs the JPEG format conversion and compression prior to
transmission via FM packet on the satellite's UHF downlink.
[ANS thanks Mineo Wakita, JE9PEL for the above information]
/EX
SB SAT (AT) AMSAT $ANS-188.04
AMSAT 2008 Space Symposium Call For Papers
AMSAT News Service Bulletin 188.04
>From AMSAT HQ SILVER SPRING, MD.
July 6, 2008
To All RADIO AMATEURS
BID: $ANS-188.04
2008 AMSAT North America Space Symposium
24-26 October 2008, Atlanta, Georgia Call for Papers:
This is the first call for papers for the 2008 AMSAT Space Symposium and
Annual Meeting to be held October 24-26, 2008 in Atlanta, Georgia.
Proposals for papers, symposium presentations, and poster presentations
are invited on any topic of interest to the amateur satellite program.
An emphasis for this year is an educational outreach to middle and high
school students. Another topic if interest is using amateur satellite
tracking systems to monitor deep space network objects.
In particular, papers on the following topics are solicited:
* Students & Education
* ARISS
* AO-51
* P3E
* Eagle
* Deep Space Network monitoring
* Any additional satellite-related topics.
We request a one-page abstract as soon as possible. Camera ready copy
on paper or in electronic form will be due by September 1, 2008 for
inclusion in the printed symposium proceedings. Papers received after
this date may not be included in the printed proceedings.
Abstracts and papers should be sent to n8fgv(AT)amsat.org
[ANS thanks the 2008 Space Symposium Committe for the above information]
/EX
SB SAT (AT) AMSAT $ANS-188.05
ARISS Status Report for the Week of June 30, 2008
AMSAT News Service Bulletin 188.05
>From AMSAT HQ SILVER SPRING, MD.
July 6, 2008
To All RADIO AMATEURS
BID: $ANS-188.05
1. School Contacts
Two simulated ARISS contacts were held on Thursday, July 3. These
training sessions are terrestrial-based amateur radio contacts using
ARISS-equivalent equipment.
The first simulated contact was with Frank De Winne, ON1DWN, and the
ESC (Euro Space Camp) in Belgium. Ottawa South United Soccer Club in
Canada will also take part in a simulated contact with astronaut Bob
Thirsk, W5/VA3CSA.
Round Rock Texas Scout Pack #304 and Blackland Prairie Elementary
School in Round Rock, Texas had an ARISS contact on Friday, July 4.
This event introduced scouts to the concepts required for their radio
merit badges, giving them a practical example of amateur radio in
action. It also provided an activity for the scientist badge. The
entire Pack (50-60 boys of various ranks) will be involved, as well
as select Blackland Prairie Elementary School staff and students.
Pack 304 will participate in a contest to determine the best questions
to ask the astronaut. Media (newspaper, radio, television) coverage
is planned and the governor will be invited.
An ARISS contact has been scheduled with the National Agriculture Museum
in Ottawa, Ontario, Canada on Wednesday, July 9 at 15:14 UTC. Telebridge
station W6SRJ in Santa Rosa, California will assist with the contact. The
museum is a large research facility in the City of Ottawa covering over
1000 years of major contributions to agricultural progress. A public camp
is part of the overall operation of the farm.
2. Successful Russian Contact
Kursk State University students participated in an ARISS contact
during the Slavic Commonwealth Forum (formerly the International Congress
of Slavic States conference) in Sochi, Russia (on the Black Sea). The
students spoke with Oleg Kononenko, RN3DX, on June 22.
3. Robinson Elementary School Contact Successful
On Wednesday, June 25, students from Robinson Elementary School in
Robinson, Texas experienced an ARISS contact via the telebridge station
WH6PN in Hawaii. Eleven students were able to ask one question each of
astronaut Greg Chamitoff, KD5PKZ, as an audience of nearly 300 looked on.
After the contact, the bridge connection was kept up to answer the stu-
dents' remaining questions. The audio was available via IRLP.
4. Astronaut Training Status
Astronauts Joe Acaba, KE5DAR, and Ricky Arnold, KE5DAU, participated in
an ARISS basic operations training session on Thursday, June 26 at JSC.
Both crew members are assigned to the STS-119 mission, which will bring
Koichi Wakata to the ISS and return Sandy Magnus.
Nicole Stott, KE5GJN, Sandy Magnus, KE5FYE, and JAXA astronauts Koichi
Wakata, KC5ZTA, and Soichi Noguchi, KD5TVP, received training on the
ARISS ham radio equipment. Photos of the Energia training session are
available on the following Web site:
http://www.energia.ru/eng/news/news-2008/photo_06-20.html
5. Under the Hood Posts SuitSat Article and Video
SuitSat appears on the cover of the June issue of Under the Hood, a
supplemental issue of the EE Times. A link to the digital issue may
be found here: http://www.nxtbook.com/nxtbooks/cmp/uth062308/
A video of ARISS member Steve Bible's talk on SuitSat given at the
Embedded Systems Conference (EMS) in April 2008 has also been posted
on the Under the Hood Web site. See:
http://cmptv.net/teardown/SuitSat
6. ARISS International Team Meeting Held
The ARISS monthly teleconference was held on Tuesday, June 17. Agenda
items covered included the upcoming Moscow meeting, Amateur Radio on
the Columbus module (ARCOL) and the status of SuitSat-2. Minutes have
been posted to the ARISS Web site.
See: http://www.rac.ca/ariss/arisstel2008-06-17.htm
7. ARISS Delegate Recognized at Ham Fair
ARISS delegate Gaston Bertels, ON4WF, was recognized at the Ham Fair
in Friedrichshafen, Germany for his many contributions to amateur radio
including his ARISS work, his efforts on the Columbus antennas, and his
selection for the CQ Hall of Fame. Ham Fair is the largest amateur radio
convention in Europe and was held over the weekend of June 27-29.
8. Amateur Radio Video Posted
The American Radio Relay League (ARRL) held its annual Field Day over
the June 28-29 weekend. A Field Day video has been posted on YouTube.
It features the International Space Station and/or ARISS program several
times. To view this, see:
http://www.youtube.com/watch?v=varHL752Odk
[ANS thanks Carol, KB3LKI for the above information]
/EX
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 additional benefits.
Application forms are available from the AMSAT Office.
73,
This week's ANS Editor,
JoAnne Maenpaa, K9JKM
K9JKM at amsat dot org
------------------------------
Message: 3
Date: Sun, 6 Jul 2008 01:23:26 +0200
From: "Szegedy" <szegedy.zolilaci(AT)t-online.hu>
Subject: [amsat-bb] TR-751
To: <amsat-bb(AT)amsat.org>
Message-ID: <C07FB1C1F03C41A6A041276FDD791A34(AT)zolip9rqwahrmf>
Content-Type: text/plain; charset="iso-8859-2"
Dear friend!
I like to ask you:
If my Kenwood TR-751 is in scanning mode I hear impulse noise(about in every
0.1 second) from speaker if I near the speaker(5cm) or use a headphone if
volume is 12clock position.
Can you check it with other TR-751?
What cause this problem?
Other people doesnt have this problem with TR-751.
I realised that if I rotate the main dial I hear also this sound .Why?
Thanks
Zoli/HG5AZR
------------------------------
Message: 4
Date: Sun, 6 Jul 2008 10:53:45 +0200
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
Subject: [amsat-bb] Fw: Re: NASA's American Student Moon Orbiter...
To: "AMSAT-BB" <amsat-bb(AT)amsat.org>, <kl7uw(AT)acsalaska.net>, "Joe"
<nss(AT)mwt.net>, "G0MRF David Bowman" <g0mrf(AT)aol.com>
Message-ID: <003501c8df45$cca40d60$0201a8c0(AT)tin.it>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: G0MRF(AT)aol.com
To: nss(AT)mwt.net
Cc: domenico.i8cvs(AT)tin.it ; kl7uw(AT)acsalaska.net
Sent: Saturday, July 05, 2008 1:21 AM
Subject: Re: [amsat-bb] Re: NASA's American Student Moon Orbiter...
Hi Joe.
Looking at 70cm up and 2m down, Dom has shown the 2m path can be achieved
with a 13dB gain antenna on the ground and 10 Watts on the satellite. That's a
very small bandwidth transponder
For the uplink, it's not quite as easy.
I've just run a link budget calculator and it looks like you need about 80
Watts and 20dB of antenna gain on 70cm. That produces around 5000 Watts ERP
(allowing for losses)
As Dom pointed out, you dont just need a signal thats just above the noise
level at the satellite. Up there you need enough of a signal at the receiver
so that the satellites transmitter can generate a decent amount of power on
2m.
The 5kW ERP generates a signal around 16dB above noise at the satellite.
With luck, that will be sufficient to produce enough power on the 2m downlink.
Of course there are a lot of variables and 'detail' . but 5kW ERP up and a
13dB gain antenna on the downlink are 'In the ballpark' for a minimal working
U/V system.
Thanks
David
Hi David, G0MRF
Looking at the specifications of AO40 I found that at 435 MHz the equivalent
noise temperature of the RX is
TN (k) = 500 kelvin
The Prx (23) i.e. the power needed by the receiver to develope a signal of
23 dB over the noise is -145 dBW
The 435 MHz satellite antenna gain is 14 dBi
It is not specified the transponder output power with a S/N=23 dB because it
depends on what transponder is intended to be used for the downlink.
Probably -145 dBW at the RX input is the power needed to get a S/N = 23 dB
at the IF input before to be switched by the matrix to different
transponders.
By the way the attenuation earth to moon at 435 MHz for 400.000 km is 197 dB
and going back to calculations
we get :
TX power at 435 MHz on earth........................ + 20 dBW (100 W)
435 MHz antenna gain on earth ....................... + 18 dB
--
---------------
EIRP of the ground station................................ + 38 dBW ( 6.3
kW)
Attenuation 435 MHz for 400.000 km .............. -197 dB
--
----------------
Power received on a 435 MHz isotropic........... - 159 dBW
antenna at a distance of 400.000 km
Satellite antenna gain ......................................... + 14 dBi
------------------
Received power at RX input for S/N=23 dB.... - 145 dBW
It seems that both calculations match and 5 kW to 6 kW EIRP up on 70 cm and
13 dBi antenna gain on the 2 meters downlink are a minimum necessary provided
that the satellite antennas orbiting around the moon are constantly directed
toward the earth but this is a very difficult task.
73" de
i8CVS Domenico
------------------------------
Message: 5
Date: Sun, 6 Jul 2008 12:24:18 -0000
From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
Subject: [amsat-bb] Re: Fw: Re: NASA's American Student Moon
Orbiter...
To: "i8cvs" <domenico.i8cvs(AT)tin.it>, "AMSAT-BB" <amsat-bb(AT)amsat.org>,
<kl7uw(AT)acsalaska.net>, "Joe" <nss(AT)mwt.net>, "G0MRF David
Bowman"
<g0mrf(AT)aol.com>
Message-ID: <000901c8df63$3747ae20$0201a8c0(AT)your6bvpxyztoq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
UV is a problem as hams in much of the U.S. are limited to 1 kW EIRP on 70
cm. The military is the primary user of the band. Recently, some repeaters
near PAVE PAWS sites have had to reduce power to 5 W due to interference
with the return signal from the 4 GW EIRP RADAR.
73,
John
KD6OZH
----- Original Message -----
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
To: "AMSAT-BB" <amsat-bb(AT)amsat.org>; <kl7uw(AT)acsalaska.net>; "Joe"
<nss(AT)mwt.net>; "G0MRF David Bowman" <g0mrf(AT)aol.com>
Sent: Sunday, July 06, 2008 08:53 UTC
Subject: [amsat-bb] Fw: Re: NASA's American Student Moon Orbiter...
> ----- Original Message -----
> From: G0MRF(AT)aol.com
> To: nss(AT)mwt.net
> Cc: domenico.i8cvs(AT)tin.it ; kl7uw(AT)acsalaska.net
> Sent: Saturday, July 05, 2008 1:21 AM
> Subject: Re: [amsat-bb] Re: NASA's American Student Moon Orbiter...
>
>
> Hi Joe.
>
> Looking at 70cm up and 2m down, Dom has shown the 2m path can be achieved
> with a 13dB gain antenna on the ground and 10 Watts on the satellite.
> That's a very small bandwidth transponder
>
> For the uplink, it's not quite as easy.
> I've just run a link budget calculator and it looks like you need about
> 80 Watts and 20dB of antenna gain on 70cm. That produces around 5000 Watts
> ERP (allowing for losses)
>
> As Dom pointed out, you dont just need a signal thats just above the
> noise level at the satellite. Up there you need enough of a signal at the
> receiver so that the satellites transmitter can generate a decent amount
> of power on 2m.
>
> The 5kW ERP generates a signal around 16dB above noise at the satellite.
> With luck, that will be sufficient to produce enough power on the 2m
> downlink.
>
> Of course there are a lot of variables and 'detail' . but 5kW ERP up and
> a 13dB gain antenna on the downlink are 'In the ballpark' for a minimal
> working U/V system.
>
> Thanks
>
> David
>
> Hi David, G0MRF
>
> Looking at the specifications of AO40 I found that at 435 MHz the
> equivalent noise temperature of the RX is
> TN (k) = 500 kelvin
> The Prx (23) i.e. the power needed by the receiver to develope a signal
> of 23 dB over the noise is -145 dBW
> The 435 MHz satellite antenna gain is 14 dBi
> It is not specified the transponder output power with a S/N=23 dB because
> it depends on what transponder is intended to be used for the downlink.
> Probably -145 dBW at the RX input is the power needed to get a S/N = 23
> dB at the IF input before to be switched by the matrix to different
> transponders.
>
> By the way the attenuation earth to moon at 435 MHz for 400.000 km is 197
> dB and going back to calculations
> we get :
>
> TX power at 435 MHz on earth........................ + 20 dBW (100 W)
> 435 MHz antenna gain on earth ....................... + 18 dB
>
> -----------------
> EIRP of the ground station................................ + 38 dBW ( 6.3
> kW)
>
> Attenuation 435 MHz for 400.000 km .............. -197 dB
>
> ------------------
> Power received on a 435 MHz isotropic........... - 159 dBW
> antenna at a distance of 400.000 km
> Satellite antenna gain ......................................... + 14 dBi
>
> ------------------
> Received power at RX input for S/N=23 dB.... - 145 dBW
>
> It seems that both calculations match and 5 kW to 6 kW EIRP up on 70 cm
> and 13 dBi antenna gain on the 2 meters downlink are a minimum necessary
> provided that the satellite antennas orbiting around the moon are
> constantly directed toward the earth but this is a very difficult task.
>
> 73" de
>
> i8CVS Domenico
>
>
>
>
>
>
> _______________________________________________
> Sent via AMSAT-BB(AT)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
------------------------------
Message: 6
Date: Sun, 6 Jul 2008 19:29:26 +0200 (CEST)
From: "Rob Hardenberg PE1ITR" <rob(AT)itr-datanet.com>
Subject: [amsat-bb] AO-51 L-Band Packet Uplink
To: amsat-bb(AT)amsat.org
Message-ID:
<35722.62.194.218.110.1215365366.squirrel(AT)customer.itr-datanet.com>
Content-Type: text/plain;charset=iso-8859-1
Hi All,
I'am trying to access AO-51 9600Bd packet uplink on 1268.700MHz but had no
succes so far. Maybe
someone on the amsat bb group has some experience on this?
I see on the downlink the message "Frames heard from PACB-1". I think it means
the receiver is
getting some signal but can't decode it.
I believe my 23cm transmitter is working ok with 10w output into 26el yagi.
Also the 9600bd is
working OK because I can connect to local stations.
I see no other traffic on the sat so it seems to me the L band receiver of ao-
51 is not to sensitive.
73 Rob PE1ITR
http://www.pe1itr.com
------------------------------
Message: 7
Date: Sun, 6 Jul 2008 13:48:24 -0400
From: "Gould Smith" <gouldsmi(AT)bellsouth.net>
Subject: [amsat-bb] Re: AO-51 L-Band Packet Uplink
To: <rob(AT)itr-datanet.com>, <amsat-bb(AT)amsat.org>
Message-ID: <6E9B4BB6F1854037AB745E43A831DF31(AT)GouldMainPC>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I have the L band receiver off while I am doing testing on the transmit
power level and battery discharge rate. I updated the AO-51 message to
reflect this. The charge and discharge rates appear to have changed
following the period of no eclipse that ended in April.
As far as the digital downlink, you should be able to decode it without any
problem if you are receiving a signal with a good S/N ratio. I can tell a
good deal of difference between winter and summer receive levels, because of
foliage, but get everything well once above the trees. I get data when
through the trees, but not everything.
The transmit power has also been down due to the length of eclipse that
peaked about 2 weeks ago and will continue to get shorter until Sept when we
will see a no eclipse period for about 8 months.
This morning I set TXA to 430 mW (digital downlink) and TXB to 470 mW
(analog downlink). So pretty good power levels for both transmitters. A
month ago they were in the 340 mW range.
73,
Gould, WA4SXM
AO-51 command station
----- Original Message -----
From: "Rob Hardenberg PE1ITR" <rob(AT)itr-datanet.com>
To: <amsat-bb(AT)amsat.org>
Sent: Sunday, July 06, 2008 1:29 PM
Subject: [amsat-bb] AO-51 L-Band Packet Uplink
> Hi All,
>
> I'am trying to access AO-51 9600Bd packet uplink on 1268.700MHz but had no
> succes so far. Maybe
> someone on the amsat bb group has some experience on this?
> I see on the downlink the message "Frames heard from PACB-1". I think it
> means the receiver is
> getting some signal but can't decode it.
> I believe my 23cm transmitter is working ok with 10w output into 26el
> yagi. Also the 9600bd is
> working OK because I can connect to local stations.
> I see no other traffic on the sat so it seems to me the L band receiver of
> ao-51 is not to sensitive.
>
>
> 73 Rob PE1ITR
> http://www.pe1itr.com
>
> _______________________________________________
> Sent via AMSAT-BB(AT)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
------------------------------
Message: 8
Date: Sun, 6 Jul 2008 14:04:06 -0400
From: "Charles Pennington" <chrlsp(AT)verizon.net>
Subject: [amsat-bb] Free Items-you pick up
To: "AMSAT BB" <AMSAT-BB(AT)AMSAT.ORG>
Message-ID: <001b01c8df92$af3a6c40$4101a8c0(AT)tempest6>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
FEE FREE FREE
2 Rolls 1000 feet each, RG62 coaxial cable.
2 pieces of 1/2 inch hardline, each about 100 feet, also some other misc
lenght pieces, some miss hardline connectors, some new in boxes.
you pick up at my qth, suburban philly, zip 19018. contact off bb. Bud
K3NMF (1849)
chrlsp(AT)verizon.net
Thanks
Bud K3NMF
------------------------------
Message: 9
Date: Sun, 06 Jul 2008 10:28:51 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: AO-51 L-Band Packet Uplink
To: <amsat-bb(AT)amsat.org>
Message-ID: <200807061828.m66ISpWj000841(AT)iris.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
Gould,
Great feedback that you provide to users, thanks!
It will be a few more weeks until I get my satellite ground station
re-erected. I had a pretty good AO-40 station during that era and,
with a house move in summer of 2006, I have not gotten it
re-installed. I do have the ten-foot tower installed (which hinges
over to the ground for antenna installationor maint.), so I hope get
to installing the antennas, sometime soon. So, for now, I read the
observations and comments with interest.
In time, I hope to be able to provide some telemetry reports. I'm
guessing that mode-LU mode and 9K6 telemetry require some good
frequency auto-tune and auto-tracking capabilities for unattended or
hands-off observations. I hope to add that after the antennas and
radio equipment are again operational.
We will look forward to Andrew's visit to the Alaska ARRL Hamfest in
August to inform on latest happenings in Amsat.
73 Ed - KL7UW
http://www.kl7uw.com/sat.htm
http://www.akhamfest.com
At 09:48 AM 7/6/2008, Gould Smith wrote:
>I have the L band receiver off while I am doing testing on the transmit
>power level and battery discharge rate. I updated the AO-51 message to
>reflect this. The charge and discharge rates appear to have changed
>following the period of no eclipse that ended in April.
>As far as the digital downlink, you should be able to decode it without any
>problem if you are receiving a signal with a good S/N ratio. I can tell a
>good deal of difference between winter and summer receive levels, because of
>foliage, but get everything well once above the trees. I get data when
>through the trees, but not everything.
>
>The transmit power has also been down due to the length of eclipse that
>peaked about 2 weeks ago and will continue to get shorter until Sept when we
>will see a no eclipse period for about 8 months.
>
>This morning I set TXA to 430 mW (digital downlink) and TXB to 470 mW
>(analog downlink). So pretty good power levels for both transmitters. A
>month ago they were in the 340 mW range.
>
>73,
>Gould, WA4SXM
>AO-51 command station
>
>----- Original Message -----
>From: "Rob Hardenberg PE1ITR" <rob(AT)itr-datanet.com>
>To: <amsat-bb(AT)amsat.org>
>Sent: Sunday, July 06, 2008 1:29 PM
>Subject: [amsat-bb] AO-51 L-Band Packet Uplink
>
>
> > Hi All,
> >
> > I'am trying to access AO-51 9600Bd packet uplink on 1268.700MHz but had no
> > succes so far. Maybe
> > someone on the amsat bb group has some experience on this?
> > I see on the downlink the message "Frames heard from PACB-1". I think it
> > means the receiver is
> > getting some signal but can't decode it.
> > I believe my 23cm transmitter is working ok with 10w output into 26el
> > yagi. Also the 9600bd is
> > working OK because I can connect to local stations.
> > I see no other traffic on the sat so it seems to me the L band receiver of
> > ao-51 is not to sensitive.
> >
> >
> > 73 Rob PE1ITR
> > http://www.pe1itr.com
> >
> > _______________________________________________
> > Sent via AMSAT-BB(AT)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(AT)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(AT)amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 3, Issue 336
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