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Today's Topics:
1. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
(Joe Westbrook)
2. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
(John B. Stephensen)
3. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
(John B. Stephensen)
4. Re: SSB Preamp (Alan P. Biddle)
5. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
(Joe Westbrook)
6. Re: AMSAT HEO design evolution (longish) (Bruce Robertson)
7. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NAPriorities
(Andrew Glasbrenner)
8. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
(Sebastian)
9. Fw: For Sale "TrakBox" Satellite tracker --- REDUCED Price
(Robert Felt)
10. Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
(Nigel Gunn G8IFF/W8IFF)
11. Re: SSB Preamp (wouter weggelaar)
----------------------------------------------------------------------
Message: 1
Date: Tue, 12 Aug 2008 04:54:50 -0500
From: "Joe Westbrook" <k7zt(AT)suddenlink.net>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
To: <amsat-bb(AT)amsat.org>, "Edward Cole" <kl7uw(AT)acsalaska.net>
Message-ID: <001c01c8fc61$76731560$0302a8c0(AT)corp.global.level3.com>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Edward:
For the most part, I agree with your analysis, AMSAT-NA just needs to get
that out to the membership for a up/down vote.
It would seem that based on the latest (un-scientific) pole most folks still
desire an HEO over GEO.
http://app.sgizmo.com/reports/18952/48864/4G6MMZP08F5CHHRFD5IFKRUG0SX47H/
"Eagle -wonderful when we can swing it" I really don't believe that this
will
ever happen if we shift the direction of Eagle to GEO.
I do like the MEO alternative though.
BTW; I'm working on a second retirement.
73's DE Joe K7ZT
----- Original Message -----
From: "Edward Cole" <kl7uw(AT)acsalaska.net>
To: <amsat-bb(AT)amsat.org>
Sent: Tuesday, August 12, 2008 4:01 AM
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
> And if I may make an even simpler appeal: I will take any non-FM
> satellite HEO, MEO, or GEO in a time frame that falls within our
> lifetime. Did I overstate that?
> We know that HEO's take lots of time in design, fabrication,
> space-qualification and financing. Many hams are getting up there in
> years and may not be able to wait another 10-15 years!
>
> HEO's are great fun and challenge, but a GEO would suffice vs only
> having FM Leos for the next decade.
> If the GEO is more feasible/practical/realistic, bring it on!
>
> If we can sell one with Emcomm capabilities added to our favorite
> modes, why not? If we wait on this too long, it will be done by the
> commercial sats so they will not need the ham version. Only hams
> like stuff that is "hard to use" - real world is interested in
> utility (can you hear me now)
>
> Bottom Line: "Time waits for nobody"
> P3E -great
> Eagle -wonderful when we can swing it
> P4 on Intelsat - don' t miss this ride
>
> I started accumulating "stuff" in 1996 to get on AO-10/13. 1998 got
> my Drake converters for AO-40 and the FT-847. 2000-2008 accumulating
> my stuff for mw's - is that twelve years? I will retire in 2011. I
> hope there is a satellite up there soon!
>
> At 06:33 PM 8/11/2008, John B. Stephensen wrote:
>>Hi Joe,
>>
>>The Eagle ride-share requires no engine from AMSAT as it is supplied by
>>and
>>operated by Intelsat. They have an order of magnitude more experience than
>>any AMSAT organization and a better track record. It also eliminates more
>>than half of the work in building the satellite. That has to reduce risk.
>>
>>AMSAT-NA members are working on P3E and AMSAT-NA has supplied money for
>>the
>>project so I don't see a lack of support.
>>
>>Since a HEO and GEO are at similar altitudes, I don't forsee a big
>>difference in signal strength. The only disadvantage of a GEO for hams is
>>that it doesn't move so I can't work India from here as I could on AO-13.
>>However, Molniya orbits aren't very useful to outside funders so there is
>>an
>>advantage in raising funds. Making satellites hard to use certainly
>>doesn't
>>help in rasing money. The aspect of AO-40 that QST pushed during
>>fund-rasing
>>was that it would be easier to use than AO-13.
>>
>>73,
>>
>>John
>>KD6OZH
>>
>>----- Original Message -----
>>From: "Joe Westbrook" <k7zt(AT)suddenlink.net>
>>To: "John B. Stephensen" <kd6ozh(AT)comcast.net>; <amsat-bb(AT)amsat.org>
>>Sent: Monday, August 11, 2008 22:06 UTC
>>Subject: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
>>
>>
>> > John:
>> > So regarding risk, how many HEO Satellites has AMSAT-NA launched that
>> > required firing a rocket motor to achieve a Molniya Orbit?
>> > It seems that AMSAT-DL has the lead on that front, additionally, the
>> > gentleman that did the PE3 Presentation at the AMSAT-UK Symposium
>> > indicated
>> > that PE3 uses the same platform as AO10 and AO13, and has been tested.
>> > At
>> > least we have a more predictable risk. I took a look at the Satellite
>> > history and it appears that the HEO Flights were all joint ventures
>> > with
>> > AMSAT-NA and AMSAT-DL. I recall a great deal of publicity in QST
>> > surrounding the AO40 launch including fund raising activities. Why
>> > don't
>> > we
>> > observe the same level of commitment that we had for those projects
>> > from
>> > AMSAT-NA Leadership?.
>> >
>> > AO40 provided extraordinary opportunities for the satellite
>> > experimenter,
>> > it
>> > wasn't that difficult and was great deal of fun. Additionally, it did
>> > push
>> > the operator to work on improving their station for weak signal work.
>> > Remember all of the great AO40 how to web sites that popped up?
>> > Lots of home brew projects! Lots of pictures of stations!
>> > How many of those are out there for AO51?
>> >
>> > I believe for those who endeavored to develop hardware and software
>> > definitely
>> > furthered the science. I constructed many different antennas and
>> > feeds
>> > learned a
>> > great deal all in my back yard with minimal investment using "arm
>> > strong"
>> > , home-brew az-el set up.
>> >
>> > Regarding GEO vs. HEO, I would argue that in terms of the overall
>> > experience, there are significant differences that boil down to the
>> > following::
>> > 1. GEO isn't a moving target
>> > 2. HEO has a weaker signal
>> > 3. With GEO, the antenna is locked down to a fixed Az-EL. No Doppler,
>> > no
>> > need to synchronize the orbit or to integrate software applications.
>> >
>> > I would challenge you to tell me how GEO wouldn't be an appliance.
>> > What's
>> > left
>> > once you mount your Downconverter, feed, LNA, etc, bring it to your
>> > xcvr,
>> > short of tuning across the transponder to find a clear frequency to
>> > call
>> > CQ,
>> > or to locate a contact what's left to do? I agree that GEO would be
>> > great
>> > for emergencies, nets, and long rag chews on what will be extremely
>> > crowded xponder space.
>> > Additionally, I think that you would agree that the skill level and
>> > overall experience is diminished. But
>> > that's just me.
>> >
>> > All I'm saying is allow the membership vote on how AMSAT-NA resources
>> > should
>> > be used, I don't mean to suggest we vote on the type of RX to use, but
>> > on
>> > the overall project.
>> > It is my belief that most members wouldn't want resources diverted to a
>> > GEO Project before an HEO Project is fully deployed.
>> > If we loose sight of the main goal, this process could go on for years.
>> > To be successful, AMSAT-NA needs a narrow focus as it has very little
>> > in
>> > the way of resources, both human and financial.
>> >
>> > I would be satisfied if AMSAT-NA would simply articulate a clear set of
>> > goals and priorities, hell even use the survey that was accomplished in
>> > 04.
>> > Communicate these goals to the members at large and finally stand by
>> > them.
>> > If at the end of the day those goals are not what the members want,
>> > then
>> > they can vote with their wallets.
>> >
>> > Regards,
>> > - Joe K7ZT
>> >
>> > ----- Original Message -----
>> > From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
>> > To: "Joe Westbrook" <k7zt(AT)suddenlink.net>; "Luc Leblanc"
>> > <lucleblanc6(AT)videotron.ca>; <eu-amsat(AT)yahoogroups.com>
>> > Cc: <amsat-bb(AT)amsat.org>
>> > Sent: Monday, August 11, 2008 12:12 PM
>> > Subject: Re: [amsat-bb] Re: [eu-amsat] AMSAT UK P3E Lecture Available
>> >
>> >
>> >> Since AMSAT-DL and AMSAT-NA both require funding from outside the
>> >> amateur
>> >> radio community, are going after different sources of funding, and
>> >> neither
>> >> can predict when they will get that funding, having two efforts would
>> >> seem
>> >> to double the opportunity for a non-LEO satellite.
>> >>
>> >> I don't think that the risk decreases with P3E. 50% of P3 satellites
>> >> were
>> >> lost due to failures of engines in the launch vehicle or in the
>> >> satellite.
>> >>
>> >> I don't see how having a linear transponder in a geostationary orbit
>> >> versus a Molniya orbit makes it an appliance satellite. The antennas
>> >> and
>> >> transceivers on ground are the same in either case.
>> >>
>> >> 73,
>> >>
>> >> John
>> >> KD6OZH
>> >>
>> >> ----- Original Message -----
>> >> From: "Joe Westbrook" <k7zt(AT)suddenlink.net>
>> >> To: "John B. Stephensen" <kd6ozh(AT)comcast.net>; "Luc Leblanc"
>> >> <lucleblanc6(AT)videotron.ca>; <eu-amsat(AT)yahoogroups.com>
>> >> Cc: <amsat-bb(AT)amsat.org>
>> >> Sent: Sunday, August 10, 2008 16:32 UTC
>> >> Subject: [amsat-bb] Re: [eu-amsat] AMSAT UK P3E Lecture Available
>> >>
>> >>
>> >>> John:
>> >>> Yes, you may have heard statements like in the past we've relied on
>> >>> charity,
>> >>> and Amateur Radio Operators alone can not fund a launch, what you
>> >>> haven't
>> >>> heard are any solutions for launching any HEOs. It seems that the DL
>> >>> folks
>> >>> haven't lost that as a focus, they acknowledge that as expensive as
>> >>> it
>> >>> is
>> >>> to
>> >>> launch an HEO, it is still doable. 3 - 4M Euros $4 - 5M at least they
>> >>> gave
>> >>> us a tangible figure we can work with. This amount may be a reach
>> >>> for
>> >>> AMSAT-NA alone, but given that we finally understand what it would
>> >>> take
>> >>> to
>> >>> make a HEO Launch reality, then why wouldn't we shift ALL funding
>> >>> toward
>> >>> that effort? Following the PE3 launch, if any surplus remains,
>> >>> the
>> >>> surplus could be transferred to the next HEO opportunity (Eagle). If
>> >>> no
>> >>> surplus remains then at least we would have one working HEO deployed.
>> >>>
>> >>> Additionally, at least we know the PE3 platform is well vetted, and
>> >>> would
>> >>> have the lowest risk. Rather than spending time and resources on a
>> >>> new,
>> >>> untested platform why wouldn't we just facilitate PE3 FIRST?
>> >>>
>> >>> Ok, I'll speech for myself here, but the GEO ride-share simply isn't
>> >>> an
>> >>> opportunity that will interest the HEO crowd. Launching an appliance
>> >>> to
>> >>> serve the disaster response community and entry level satellite users
>> >>> won't
>> >>> do a thing to satisfy the need for a HEO. I don't care if it's free,
>> >>> like
>> >>> AO51, I would probably get on it, make a couple contacts say "that's
>> >>> nice"
>> >>> and be done with it. Please understand, I'm not saying to abandon
>> >>> GEO
>> >>> as
>> >>> a
>> >>> viable option, just don't spend a cent on it until we launch an HEO.
>> >>>
>> >>> What we need is a satellite that enables the real sprit and intent of
>> >>> the
>> >>> Amateur Radio Service, to push the envelop of the technology, allow
>> >>> for
>> >>> experimentation, consider all of the alternative antenna solutions
>> >>> that
>> >>> our
>> >>> resourceful community developed to receive the 2.4Gig Down Link. No
>> >>> rotator
>> >>> required, different feed systems, a fairly modest resource outlay to
>> >>> get
>> >>> on
>> >>> the air. I did it with a totally home brewed system in a restricted
>> >>> neighborhood back yard. Had a blast and learned allot.
>> >>>
>> >>> ----- Original Message -----
>> >>> From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
>> >>> To: "Luc Leblanc" <lucleblanc6(AT)videotron.ca>;
>> >>> <eu-amsat(AT)yahoogroups.com>
>> >>> Cc: <amsat-bb(AT)amsat.org>
>> >>> Sent: Friday, August 08, 2008 3:14 PM
>> >>> Subject: [amsat-bb] Re: [eu-amsat] AMSAT UK P3E Lecture Available
>> >>>
>> >>>
>> >>>> I've been hearing these two statments from AMSAT-NA officals for at
>> >>>> least
>> >>>> 2
>> >>>> years -- in person and on this BB.
>> >>>>
>> >>>> 73,
>> >>>>
>> >>>> John
>> >>>> KD6OZH
>> >>>>
>> >>>> ----- Original Message -----
>> >>>> From: "Luc Leblanc" <lucleblanc6(AT)videotron.ca>
>> >>>>>
>> >>>>> Very nice presentations. One attract my attention was made by Peter
>> >>>>> Guelzow DB2OS one one of his slide we can read:
>> >>>>>
>> >>>>> ATTRACTIVENESS OF AMATEUR RADIO HAS DROPPED SIGNIFICANTLY
>> >>>>>
>> >>>>> FUNDING A SATELLITE FROM AMATEUR RESSOURCES ALONE NEVER WORKED
>> >>>>> BEFORE
>> >>>>> AND
>> >>>>> WILL NOT WORK NOW.
>> >>>>>
>> >>>>> I don't how to explain how all the wisdom and reality knowledge
>> >>>>> seems
>> >>>>> to
>> >>>>> be concentrated in Europe when speaking about amateur satellite?
>> >>>>
>> >>>> _______________________________________________
>> >>>> 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-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
------------------------------
Message: 2
Date: Tue, 12 Aug 2008 10:25:31 -0000
From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
To: <nigel(AT)ngunn.net>, <amsat-bb(AT)amsat.org>
Message-ID: <004201c8fc65$bffbdd30$0201a8c0(AT)your6bvpxyztoq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
However, it takes 3 Molniya orbit satellites for Sirius to provide
continuous coverage of the U.S. XM uses 1 geostationary satellite.
73,
John
KD6OZH
----- Original Message -----
From: "Nigel Gunn G8IFF/W8IFF" <nigel(AT)ngunn.net>
To: <amsat-bb(AT)amsat.org>
Sent: Tuesday, August 12, 2008 03:24 UTC
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
> Works OK for the US Sirius radio network with a period of approx 24 hours.
>
> John B. Stephensen wrote:
> Molniya orbits aren't very useful to outside funders
> _______________________________________________
> 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: 3
Date: Tue, 12 Aug 2008 11:05:46 -0000
From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
To: "Joe Westbrook" <k7zt(AT)suddenlink.net>, <amsat-bb(AT)amsat.org>
Message-ID: <005401c8fc6b$5f209450$0201a8c0(AT)your6bvpxyztoq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response
>
> It appears that leadership is allowing realities of
> a rare, expensive launch opportunity drive the mission rather than the
> mission driving the launch method, it's a bit like the tail wagging the
> dog
> don't you think?
>
AO-40 was the case of a rare launch opportunity driving the mission. The
AMSAT BoD has stated that the purpose of creating a relelationship with
Intelsat would be to provide multiple launch opportunities. It seems to me
that finding an affordable launch method should be the first step rather
than the last step.
73,
John
KD6OZH
------------------------------
Message: 4
Date: Tue, 12 Aug 2008 06:29:38 -0500
From: "Alan P. Biddle" <APBIDDLE(AT)UNITED.NET>
Subject: [amsat-bb] Re: SSB Preamp
To: <amsat-bb(AT)amsat.org>
Message-ID: <16ADC0B7612B4A168BDB987E64F5CCFB(AT)WA4SCA>
Content-Type: text/plain; charset="us-ascii"
Also, most TX amplifiers have a series capacitor on the input, which will
also block the DC power. With the TX amp switched off/out, there is usually
a DC path, but check the schematic.
Alan
WA4SCA
Not sure what you mean by "recognized a preamp" (I don't have a 910), but if
you have a lightning arrestor in between the rig and the preamp, they
usually block DC from passing. Mine does, so I had to power it with an
external cable (which, now that I think of it, kind of defeats the purpose
of the lightning arrestor...!).
Greg KO6TH
----------------------------------------
> Date: Mon, 11 Aug 2008 16:39:56 -0400
> From: roi(AT)optonline.net
> To: AMSAT-BB(AT)amsat.org
> Subject: [amsat-bb] SSB Preamp
>
> Hi,
>
> Is anyone using a SSB SP-7000 preamp and an Icom 910H powered via direct
> feed from the coax. I am not able to turn the preamp on with this method,
I
> set the menu for the preamp and the front panel; it recognizes a preamp
but
> it's not working, any ideas?
>
> 73 Peter
> WB2OQQ
>
> _______________________________________________
> 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
_________________________________________________________________
Your PC, mobile phone, and online services work together like never before.
http://clk.atdmt.com/MRT/go/108587394/direct/01/
_______________________________________________
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: 5
Date: Tue, 12 Aug 2008 07:44:16 -0500
From: "Joe Westbrook" <k7zt(AT)suddenlink.net>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
To: "John B. Stephensen" <kd6ozh(AT)comcast.net>, <amsat-bb(AT)amsat.org>
Message-ID: <000e01c8fc79$21b1ec50$0302a8c0(AT)corp.global.level3.com>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response
John:
That certainly is one approach, I'm not saying that there is anything wrong
with that, it's just a change in the stated goals of Eagle.
The leadership needs to get in front of this and announce this is a
significant shift in organizational strategy if indeed that is the plan.
At they same time for the sake of honesty they should probably tell folks
that this will end AMSAT-NA sponsorship of an HEO (Molmiya Orbit)
anytime soon or even in their lifetime ;-/
- Joe
----- Original Message -----
From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
To: "Joe Westbrook" <k7zt(AT)suddenlink.net>; <amsat-bb(AT)amsat.org>
Sent: Tuesday, August 12, 2008 6:05 AM
Subject: Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
> >
>> It appears that leadership is allowing realities of
>> a rare, expensive launch opportunity drive the mission rather than the
>> mission driving the launch method, it's a bit like the tail wagging the
>> dog
>> don't you think?
>>
> AO-40 was the case of a rare launch opportunity driving the mission. The
> AMSAT BoD has stated that the purpose of creating a relelationship with
> Intelsat would be to provide multiple launch opportunities. It seems to me
> that finding an affordable launch method should be the first step rather
> than the last step.
>
> 73,
>
> John
> KD6OZH
>
>
------------------------------
Message: 6
Date: Tue, 12 Aug 2008 10:06:45 -0300
From: "Bruce Robertson" <ve9qrp(AT)gmail.com>
Subject: [amsat-bb] Re: AMSAT HEO design evolution (longish)
To: Trevor <m5aka(AT)yahoo.co.uk>
Cc: AMSAT BB <amsat-bb(AT)amsat.org>
Message-ID:
<49657a760808120606u2fb7f47bpc17077598f214bf8(AT)mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
All the reasoning below is quite progressive. Thanks, everyone. If I
can piggy-back on Trevor's suggestions, I suspect a cubesat-based
collaboration with a university group that wants to try out a new
propulsion scheme would be idea. We would offer our expertise in
communications and antenna design and, more importantly, our
telemetry-collecting strength-in-numbers. They would build the
propulsion system, either ion-based, or sail, or whatever.
Consider that, for us, many kinds of failures of these sorts of
propulsion systems would not be catastrophic: we'd just have another
LEO at 700km to play with. Moreover, if the satellite took 2 years to
reach its target altitude, I think we'd all find it great fun to watch
and track that. Perhaps if it were a propulsion system like ion, that
requires the use of the solar panels, we could periodically switch the
propulsion off and try out the transponder to 'wet our whistles'.
Finally, this sort of scheme would be very nicely suited for S-band
work, since the doppler shift would not be as painful with the higher
altitude. With the lower altitude, but lower power, perhaps the 60cm
dish could be used, thereby allowing a more easily camouflaged antenna
set-up for US hams in restricted circumstances. (The uplink antenna is
something of a problem, but perhaps 50w on 70cm into a attic-mounted
beam would still do well.)
Nobody's mentioned attitude control yet. I assume that with a
propulsion system attitude will have to be finely controlled. Is this
a problem?
73, Bruce
VE9QRP
On Mon, Aug 11, 2008 at 6:55 PM, Trevor <m5aka(AT)yahoo.co.uk> wrote:
> A MEO orbit at 4500 km would be good compromise between range, path loss,
radiation, time delay and doppler shift but the problem is geting there or to
higher MEOs. Inevitably you'd end up with a propulsion system on your sat to
get from a 'cheap' 700 km orbit. But once you've got such a system the
additional costs to get it into an HEO orbit are negligable.
>
> However, as the web page http://www.g0mrf.freeserve.co.uk/MEOSAT.htm shows
there are other propulsion systems that are feasable assuming you're prepared
to wait longer to achieve the final orbit.
>
> One of the great things about Cubesats is that they allow you to try
experiments such as alternate means of achieving orbital changes at 'little'
cost.
>
> 73 Trevor M5AKA
>
> --- On Mon, 11/8/08, Graham Shirville <g.shirville(AT)btinternet.com> wrote:
>> From: Graham Shirville <g.shirville(AT)btinternet.com>
>> Subject: Re: [amsat-bb] Re: AMSAT HEO design evolution (longish)
>> To: "SV1BSX" <sv1bsx(AT)yahoo.gr>, G0MRF(AT)aol.com, m5aka(AT)yahoo.co.uk,
amsat-bb(AT)amsat.org
>> Date: Monday, 11 August, 2008, 10:29 PM
>> > if we can not launch a HEO, why not about a MEO? I
>> remember a nice page
>> > around Internet (unfortunately I can't find this
>> page any longer)
>>
>>
>> Try one of David's own pages:
>>
>> http://www.g0mrf.freeserve.co.uk/MEOSAT.htm
>>
>> Really interesting and thought provoking reading!
>>
>> 73
>>
>> Graham
>> G3VZV
>
> Send instant messages to your online friends http://uk.messenger.yahoo.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: 7
Date: Tue, 12 Aug 2008 09:10:14 -0400
From: "Andrew Glasbrenner" <glasbrenner(AT)mindspring.com>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and
AMSAT-NAPriorities
To: "Joe Westbrook" <k7zt(AT)suddenlink.net>, "John B. Stephensen"
<kd6ozh(AT)comcast.net>, <amsat-bb(AT)amsat.org>
Message-ID: <C527123B126C4BB099F5EA62EA3E9ABB(AT)Andrewlaptop>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
At this point AMSAT is going to take the first thing that gets us above LEO
that we can afford. If that is HEO, so be it. If it is GEO, it's GEO. Being
divided and fussy over the details only detracts from the effort. We are
basically beggars in the launch market, and we all know the saying about
beggars and choosers. The mission is to provide long access time satellite
comms on a daily, then 24/7 basis. How that happens is yet to be
determined...
Sorry to be so brief but I have a lot going on with my day job at the
moment. There will be more information forthcoming.
73, Drew KO4MA
----- Original Message -----
From: "Joe Westbrook" <k7zt(AT)suddenlink.net>
To: "John B. Stephensen" <kd6ozh(AT)comcast.net>; <amsat-bb(AT)amsat.org>
Sent: Tuesday, August 12, 2008 8:44 AM
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and
AMSAT-NAPriorities
> John:
> That certainly is one approach, I'm not saying that there is anything
> wrong
> with that, it's just a change in the stated goals of Eagle.
> The leadership needs to get in front of this and announce this is a
> significant shift in organizational strategy if indeed that is the plan.
>
> At they same time for the sake of honesty they should probably tell folks
> that this will end AMSAT-NA sponsorship of an HEO (Molmiya Orbit)
> anytime soon or even in their lifetime ;-/
>
> - Joe
>
> ----- Original Message -----
> From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
> To: "Joe Westbrook" <k7zt(AT)suddenlink.net>; <amsat-bb(AT)amsat.org>
> Sent: Tuesday, August 12, 2008 6:05 AM
> Subject: Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities
>
>
>> >
>>> It appears that leadership is allowing realities of
>>> a rare, expensive launch opportunity drive the mission rather than the
>>> mission driving the launch method, it's a bit like the tail wagging the
>>> dog
>>> don't you think?
>>>
>> AO-40 was the case of a rare launch opportunity driving the mission. The
>> AMSAT BoD has stated that the purpose of creating a relelationship with
>> Intelsat would be to provide multiple launch opportunities. It seems to
>> me
>> that finding an affordable launch method should be the first step rather
>> than the last step.
>>
>> 73,
>>
>> John
>> KD6OZH
>>
>>
>
> _______________________________________________
> 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: Tue, 12 Aug 2008 09:24:10 -0400
From: Sebastian <w4as(AT)bellsouth.net>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
To: AMSAT BB <amsat-bb(AT)amsat.org>
Message-ID: <2E7583AB-747B-4F53-8FE6-BFAB8D88D71C(AT)bellsouth.net>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Actually, XM has 2 functioning satellites, and 2 orbiting spares.
This makes the current active satellites as XM-3 "Rhythm" and XM-4
"Blues" with two in-orbit spares:
http://en.wikipedia.org/wiki/XM_Satellite_Radio
73 de W4AS
Sebastian
On Aug 12, 2008, at 6:25 AM, John B. Stephensen wrote:
> However, it takes 3 Molniya orbit satellites for Sirius to provide
> continuous coverage of the U.S. XM uses 1 geostationary satellite.
>
> 73,
>
> John
> KD6OZH
>
> ----- Original Message -----
> From: "Nigel Gunn G8IFF/W8IFF" <nigel(AT)ngunn.net>
> To: <amsat-bb(AT)amsat.org>
> Sent: Tuesday, August 12, 2008 03:24 UTC
> Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
> Priorities
>
>
>> Works OK for the US Sirius radio network with a period of approx 24
>> hours.
>>
>> John B. Stephensen wrote:
>> Molniya orbits aren't very useful to outside funders
------------------------------
Message: 9
Date: Tue, 12 Aug 2008 09:37:07 -0400
From: "Robert Felt" <robertfelt(AT)bellsouth.net>
Subject: [amsat-bb] Fw: For Sale "TrakBox" Satellite tracker ---
REDUCED Price
To: <amsat-bb(AT)amsat.org>
Message-ID: <5C3F0858110C4889BE311D95838EEFC1(AT)BobPC>
Content-Type: text/plain; charset="iso-8859-1"
SOLD as of 8-11-08 (AT) 1807EDT
----- Original Message -----
From: Robert Felt
To: amsat-bb(AT)amsat.org
Sent: Monday, August 11, 2008 6:11 PM
Subject: For Sale "TrakBox" Satellite tracker --- REDUCED Price
For Sale - REDUCED PRICE -- $100.
"TrakBox" Satellite tracker, antenna rotor controller for stand alone
operation. (JARL design, TAPR kit)
The trakbox is a self-contained, stand-alone rotor/radio control for use with
your satellite stations. Select the satellite you wish to track from a front
panel control and the TrakBox will steer your antennas in both azimuth and
elevation to track the selected satellite when it is or above your horizon. In
addition, if you have a radio with a computer interface, the TrakBox will tune
your transmitter and receiver and correct them for doppler shift. TrakBox is
set up to directly interface to Kenpro, Emmoto, and Yaesu dual-axis rotators
which include a computer interface. Trakbox includes a serial port to allow
you to set the real-time clock (which is battery backed), your station
location (latitude, longitude and elevation) and the keplerian elements for
the satellites you are interested in (up to 40 satellites may be loaded, and
the elements may be uploaded in ASCII in either the AMSAT or NASA formats). A
two-line LCD display is updated every second, showing the azimuth and!
elevation of a satellite, along with the satellite ID and GMT.
I built this kit from TAPR back in the late 1990's. It provided excellent
service. Still works great.
See Complete description and docs at TAPR web page:
http://www.tapr.org/kits_trakbox.html
Now asking only $100. (was $130). Will take PayPal.
73 --- //Bob//
Robert Felt
--KB5YZG--
1403 5th Ave West
Hendersonville, NC 28739
tel: 828-696-4103
email: kb5yzg(AT)amsat.org
------------------------------
Message: 10
Date: Tue, 12 Aug 2008 13:47:16 +0000
From: Nigel Gunn G8IFF/W8IFF <nigel(AT)ngunn.net>
Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA
Priorities
To: "John B. Stephensen" <kd6ozh(AT)comcast.net>
Cc: amsat-bb(AT)amsat.org
Message-ID: <48A19464.5020008(AT)ngunn.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
True. That 3 sats is for continuous coverage and reltively non directional
user antennas. Most amateurs have never insisted on 24 hour coverage.
John B. Stephensen wrote:
> However, it takes 3 Molniya orbit satellites for Sirius to provide
> continuous coverage of the U.S. XM uses 1 geostationary satellite.
>
> 73,
>
> John
------------------------------
Message: 11
Date: Tue, 12 Aug 2008 16:30:18 +0200
From: "wouter weggelaar" <wouterweg(AT)gmail.com>
Subject: [amsat-bb] Re: SSB Preamp
To: amsat-bb(AT)amsat.org
Message-ID:
<7abd0e260808120730lc3ea04bv88ec3794be9b62ae(AT)mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Hi Peter,
Does it show PAMP on the display or does it come on for only very shortly?
I have this setup working at the Delfi-C3 groundstation without
problems with a lightning arrestor in the circuit (gas discharge type)
If you have a short somewhere in the cable the PAMP sign will only
light very shortly and will be off again due to the protection inside
the IC-910.
You could also carefully check the setup with a bias tee if you have
one available.
Should you have access to the preamp right now (ie, its not already
outside and hard to reach) you could try with a short cable and listen
if the relay comes up (no voltage on the coax means pre-amp bypassed =
relay off)
If I understand correctly you have enabled the pre-amp in the menu?
(Press MENU long, go to 435 PRE with up and down keys and make sure it
says ON)
If you have a TX PA, then most probably it has an input capacitor as
Alan already pointed out. Try without the PA in the loop.
Good luck and 73's
Wouter Weggelaar
PA3WEG
On Tue, Aug 12, 2008 at 1:29 PM, Alan P. Biddle <APBIDDLE(AT)united.net>
wrote:
> Also, most TX amplifiers have a series capacitor on the input, which will
> also block the DC power. With the TX amp switched off/out, there is usually
> a DC path, but check the schematic.
>
> Alan
> WA4SCA
>
>
>
> Not sure what you mean by "recognized a preamp" (I don't have a 910), but if
> you have a lightning arrestor in between the rig and the preamp, they
> usually block DC from passing. Mine does, so I had to power it with an
> external cable (which, now that I think of it, kind of defeats the purpose
> of the lightning arrestor...!).
>
> Greg KO6TH
>
>
> ----------------------------------------
>> Date: Mon, 11 Aug 2008 16:39:56 -0400
>> From: roi(AT)optonline.net
>> To: AMSAT-BB(AT)amsat.org
>> Subject: [amsat-bb] SSB Preamp
>>
>> Hi,
>>
>> Is anyone using a SSB SP-7000 preamp and an Icom 910H powered via direct
>> feed from the coax. I am not able to turn the preamp on with this method,
> I
>> set the menu for the preamp and the front panel; it recognizes a preamp
> but
>> it's not working, any ideas?
>>
>> 73 Peter
>> WB2OQQ
>>
>> _______________________________________________
>> 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
>
> _________________________________________________________________
> Your PC, mobile phone, and online services work together like never before.
> http://clk.atdmt.com/MRT/go/108587394/direct/01/
> _______________________________________________
> 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 408
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