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CX2SA > SATDIG 03.07.09 01:25l 1008 Lines 34298 Bytes #999 (0) @ WW
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Today's Topics:
1. [Fwd: Re: Re: The Moon is our Future] (n0jy@xxxxxxx.xxxx
2. Re: The Moon is our Future (Jack K.)
3. Re: The Moon is our Future (Nigel Gunn G8IFF/W8IFF)
4. Has anyone considered??? (Jack K.)
5. Re: The Moon is our Future (David - KG4ZLB)
6. Re: The Moon is our Future (MM)
7. Re: The Moon is our Future (David - KG4ZLB)
8. Re: [Fwd: Re: Re: The Moon is our Future] (Joe)
9. Re: Has anyone considered??? (MM)
10. Re: The Moon is our Future (MM)
11. Re: The Moon is our Future (Nigel Gunn G8IFF/W8IFF)
12. Re: The Moon is our Future (kd8bxp@xxx.xxxx
13. Re: The Moon is our Future (tosca005@xxx.xxxx
14. Re: The Moon is our Future (Robert Bruninga)
15. How you do DOPPLER correction in Linear Transponders?
(Fabiano Moser)
16. Re: The Moon is our Future (kd8bxp@xxx.xxxx
----------------------------------------------------------------------
Message: 1
Date: Thu, 2 Jul 2009 09:40:22 -0500 (CDT)
From: n0jy@xxxxxxx.xxx
Subject: [amsat-bb] [Fwd: Re: Re: The Moon is our Future]
To: amsat-bb@xxxxx.xxx
Message-ID: <56441.170.49.217.216.1246545622.squirrel@xxxxxxx.xxx>
Content-Type: text/plain;charset=iso-8859-1
Somehow I sent this in reply to Bob instead of the group. Sorry, Bob.
> BUT one easy way to get gain is to use just a long coaxial gain
> cable. I think it takes about 22 feet of coaxial dipole
> elements at 2 meters to give about 6 dB of gain. So laying down 6 dB
gain segments on the rock of the moon is as easy as
> unrolling a spool of cable. Unrolling 8 of these with the right spacing
could yield about 17 dB.
>
> Of course this woiuld only point straight up, so it would need
> to be on a moon base in the middle of the earth facing side.
> But since there is a lot of interest in moon bases near the
> poles where there might be water, then a similar array of layed
> down coaxial cable arrays could be phased horizontally to point
> at earth. Actually, just about any direction can be obtained
> with the right spacing.
>
> ONLY problem of course is there has to be someone with legs to
> roll out the cables.
How about, if the location is very near the pole, an array that extends up
like a push-pole vertically from the craft, with tape measure type dipoles
that spring out horizontally when the pole goes up? You might need a
small rotator on the base of the pole then to make sure the dipoles point
at Earth depending on the orientation of the craft when it lands, but that
would only need to be turned once I believe, when it is deployed.
Jerry
N0JY
------------------------------
Message: 2
Date: Thu, 2 Jul 2009 06:48:51 -0600
From: "Jack K." <kd1pe.1@xxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: <kd8bxp@xxx.xxx>, <bruninga@xxxx.xxx>, "'Joe'" <nss@xxx.xxx>,
"'MM'" <ka1rrw@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxxx kg4zlb@xxxxx.xxx
Message-ID: <9F2CF63AE863425BB48C78AC2E98E5B9@xxxxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="UTF-8";
reply-type=original
I heard the same things when the first HEOs went up. It takes to much money,
it takes to much specialized equipment, it takes to much knowledge, it is
for elitists only... The bottom line is a LOT of hams used them and it took
some ingenuity, some new equipment, and yes we all had to learn now things
to use them. the bottom line is they worked and worked well... My suggestion
is quit looking at pitfalls and problems as reasons not to do something, but
as opportunities to learn to accomplish new things (or improved
communications anyway) and move forward... We can put up all the leos we
want, but until someone makes something like B. Bruninga's cell concept
work, we are only going to have more of the same, We don't need more of the
same!
DE - KD1PE
----- Original Message -----
From: <kd8bxp@xxx.xxx>
To: <bruninga@xxxx.xxx>; "'Joe'" <nss@xxx.xxx>; "'MM'" <ka1rrw@xxxxx.xxx>
Cc: "'Jack K.'" <kd1pe.1@xxxxx.xxx>; <amsat-bb@xxxxx.xxx>;
<kg4zlb@xxxxx.xxx>
Sent: Thursday, July 02, 2009 8:28 AM
Subject: Re: [amsat-bb] Re: The Moon is our Future
> Don't want to get a whole new thing started here but - I don't think we
> ever went to the moon in 1969 and I don't think we will ever goto the
> moon - in 2012 or whenever they proposed a "return" to the moon
>
> I would love to see an amatuer repeater on the moon thou - from my
> understanding EME is expensive to do, so I think it would leave most of us
> out
>
> Where as and bringing things back around - LEOs are realitive low cost to
> use to the normal everyday day
>
> I will put my two cents in for more LEOs - :-)
>
> Hey are there any geosynchinze amatuer sats up?
>
------------------------------
Message: 3
Date: Thu, 02 Jul 2009 15:11:17 +0000
From: Nigel Gunn G8IFF/W8IFF <nigel@xxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
Cc: amsat-bb@xxxxx.xxx
Message-ID: <4A4CCE15.9000602@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
The moon will require a reasonable radio and big antennas but at least it
moves very slowly and you can see it so it
should be very easy to track.
------------------------------
Message: 4
Date: Thu, 2 Jul 2009 06:40:25 -0600
From: "Jack K." <kd1pe.1@xxxxx.xxx>
Subject: [amsat-bb] Has anyone considered???
To: <bruninga@xxxx.xxx>, "'Joe'" <nss@xxx.xxx>, "'MM'"
<ka1rrw@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxxx kg4zlb@xxxxx.xxx
Message-ID: <1CB7C9A170D1422D8A94F3347759A431@xxxxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Has anyone considered the notion that the communications from a HEO or Moon
or Mars need not be analog? Has anyone considered a digital mode such as
WSJT for comms? I know for a fact people are running meteor scatter and EME
using a single beam (albeit a long one) and 150 watts. This is not out of
the reach of most hams and it is not non-viable communications mode... Heck
the US Navy even ran RTTY in the 60's from Hawaii to Maryland as a normal
mode of communications (yes it was big and wieldy, I just mentioned it as an
aside).
DE - KD1PE - Jack
>> Why go with the minimal antenna gain?
>> ... any antenna with a 3 db point that exceeds
>> 6.5 degrees is just wasting transmitter power.
>
> I think that would be about a 24 dB gain antenna. Pretty big
> and would take some careful alignment... Kinda like a realy big
> EME array
>
>> Just remember what an Oscar 10 station took
>> to have reliable communications, At Apogee
>> it was only 35,000 miles away, the Moon is ...]
>> [250,000 miles]
>
> Which is 7 times farther, squared or 50 times more power (about
> 17 dB).
>
------------------------------
Message: 5
Date: Thu, 02 Jul 2009 11:15:46 -0400
From: David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: amsat-bb@xxxxx.xxx
Message-ID: <4A4CCF22.3010104@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
On the contrary, we need more LEO's to augment and replace the existing
aged fleet.
Whilst AMSAT works on the HEO's lets put some of our efforts towards the
Universities who seem to regularly put up 2/70 satellites!
--
David
KG4ZLB
www.kg4zlb.com
Jack K. wrote:
> I heard the same things when the first HEOs went up. It takes to much
> money, it takes to much specialized equipment, it takes to much
> knowledge, it is for elitists only... The bottom line is a LOT of hams
> used them and it took some ingenuity, some new equipment, and yes we
> all had to learn now things to use them. the bottom line is they
> worked and worked well... My suggestion is quit looking at pitfalls
> and problems as reasons not to do something, but as opportunities to
> learn to accomplish new things (or improved communications anyway) and
> move forward... We can put up all the leos we want, but until someone
> makes something like B. Bruninga's cell concept work, we are only
> going to have more of the same, We don't need more of the same!
>
> DE - KD1PE
>
>
> ----- Original Message ----- From: <kd8bxp@xxx.xxx>
> To: <bruninga@xxxx.xxx>; "'Joe'" <nss@xxx.xxx>; "'MM'" <ka1rrw@xxxxx.xxx>
> Cc: "'Jack K.'" <kd1pe.1@xxxxx.xxx>; <amsat-bb@xxxxx.xxx>;
> <kg4zlb@xxxxx.xxx>
> Sent: Thursday, July 02, 2009 8:28 AM
> Subject: Re: [amsat-bb] Re: The Moon is our Future
>
>
>
>
------------------------------
Message: 6
Date: Thu, 2 Jul 2009 08:16:12 -0700 (PDT)
From: MM <ka1rrw@xxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: amsat-bb@xxxxx.xxx
Message-ID: <452029.24563.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Dear Jack:
Thank you for your great comments.
Let?s find the problems and find the solutions.
We solved the difficulties for working AO-10 and AO-13.
The Moon is the Next Generation.
Lets work together to find an affordable solution.
Which band will work the best (assuming limited antenna and power recourses
from an Un-manned Moon lander.)
The Moon will not be an ?Easy-Sat?, it will be a challenge.
However, it should be much easier to access than true EME.
Thanks all Miles WF1F MarexMG.org
--- On Thu, 7/2/09, Jack K. <kd1pe.1@xxxxx.xxx> wrote:
> From: Jack K. <kd1pe.1@xxxxx.xxx>
> Subject: Re: [amsat-bb] Re: The Moon is our Future
> To: kd8bxp@xxx.xxxx bruninga@xxxx.xxxx "'Joe'" <nss@xxx.xxx>, "'MM'"
<ka1rrw@xxxxx.xxx>
> Cc: amsat-bb@xxxxx.xxxx kg4zlb@xxxxx.xxx
> Date: Thursday, July 2, 2009, 8:48 AM
> I heard the same things when the
> first HEOs went up. It takes to much money, it takes to much
> specialized equipment, it takes to much knowledge, it is for
> elitists only... The bottom line is a LOT of hams used them
> and it took some ingenuity, some new equipment, and yes we
> all had to learn now things to use them. the bottom line is
> they worked and worked well... My suggestion is quit looking
> at pitfalls and problems as reasons not to do something, but
> as opportunities to learn to accomplish new things (or
> improved communications anyway) and move forward... We can
> put up all the leos we want, but until someone makes
> something like B. Bruninga's cell concept work, we are only
> going to have more of the same, We don't need more of the
> same!
>
> DE - KD1PE
>
>
------------------------------
Message: 7
Date: Thu, 02 Jul 2009 11:20:34 -0400
From: David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: amsat-bb@xxxxx.xxx
Message-ID: <4A4CD042.1090408@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
Just a question but if you do not think the US got to the Moon in 1969
and neither do you think they will get back to the Moon in 2012, how do
you propose seeing an amateur repeater on the Moon?
Get the crew of the ISS to toss out a repeater, like SuitSat, but throw
it really, really hard in the general direction of the Moon and hope it
lands?
I don't understand your logic.
73 David
KG4ZLB
kd8bxp@xxx.xxx wrote:
> Don't want to get a whole new thing started here but - I don't think we ever
went to the moon in 1969 and I don't think we will ever goto the moon - in
2012 or whenever they proposed a "return" to the moon
>
> I would love to see an amatuer repeater on the moon thou - from my
understanding EME is expensive to do, so I think it would leave most of us out
>
> Where as and bringing things back around - LEOs are realitive low cost to
use to the normal everyday day
>
> I will put my two cents in for more LEOs - :-)
>
> Hey are there any geosynchinze amatuer sats up?
>
> LeRoy, KD8BXP
> http://www.HamOhio.com
> -
------------------------------
Message: 8
Date: Thu, 02 Jul 2009 10:21:45 -0500
From: Joe <nss@xxx.xxx>
Subject: [amsat-bb] Re: [Fwd: Re: Re: The Moon is our Future]
To: amsat-bb@xxxxx.xxx
Message-ID: <4A4CD089.6050403@xxx.xxx>
Content-Type: text/plain; charset=us-ascii; format=flowed
What someone really needs to do is to run a real actual link budget, and
see what things really like are.
Joe
n0jy@xxxxxxx.xxx wrote:
>Somehow I sent this in reply to Bob instead of the group. Sorry, Bob.
>
>
>
>>BUT one easy way to get gain is to use just a long coaxial gain
>>cable. I think it takes about 22 feet of coaxial dipole
>>elements at 2 meters to give about 6 dB of gain. So laying down 6 dB
>>
>>
>gain segments on the rock of the moon is as easy as
>
>
>>unrolling a spool of cable. Unrolling 8 of these with the right spacing
>>
>>
>could yield about 17 dB.
>
>
>>Of course this woiuld only point straight up, so it would need
>>to be on a moon base in the middle of the earth facing side.
>>But since there is a lot of interest in moon bases near the
>>poles where there might be water, then a similar array of layed
>>down coaxial cable arrays could be phased horizontally to point
>>at earth. Actually, just about any direction can be obtained
>>with the right spacing.
>>
>>ONLY problem of course is there has to be someone with legs to
>>roll out the cables.
>>
>>
>
>How about, if the location is very near the pole, an array that extends up
>like a push-pole vertically from the craft, with tape measure type dipoles
>that spring out horizontally when the pole goes up? You might need a
>small rotator on the base of the pole then to make sure the dipoles point
>at Earth depending on the orientation of the craft when it lands, but that
>would only need to be turned once I believe, when it is deployed.
>
>Jerry
>N0JY
>
>
>
>
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. 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
>
>
>------------------------------------------------------------------------
>
>
>No virus found in this incoming message.
>Checked by AVG - www.avg.com
>Version: 8.5.375 / Virus Database: 270.13.2/2214 - Release Date: 07/02/09
05:54:00
>
>
>
------------------------------
Message: 9
Date: Thu, 2 Jul 2009 08:21:50 -0700 (PDT)
From: MM <ka1rrw@xxxxx.xxx>
Subject: [amsat-bb] Re: Has anyone considered???
To: bruninga@xxxx.xxxx "'Joe'" <nss@xxx.xxx>, "Jack K."
<kd1pe.1@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxxx kg4zlb@xxxxx.xxx
Message-ID: <775283.70328.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Yes, Digital is an option.
However, i would want it to pass through the analog transponder unprocessed.
The reason is that we can't afford the Million dollar Radiation hardened chips
to support digital processing required on satellites.
DSP or SDR will add to the Cost and add many years to the project.
WE need projects much faster than have been delivered in the past, 1-2 year
schedules not 10 year schedules.
Miles
--- On Thu, 7/2/09, Jack K. <kd1pe.1@xxxxx.xxx> wrote:
> From: Jack K. <kd1pe.1@xxxxx.xxx>
> Subject: Has anyone considered???
> To: bruninga@xxxx.xxxx "'Joe'" <nss@xxx.xxx>, "'MM'" <ka1rrw@xxxxx.xxx>
> Cc: amsat-bb@xxxxx.xxxx kg4zlb@xxxxx.xxx
> Date: Thursday, July 2, 2009, 8:40 AM
> Has anyone considered the notion that
> the communications from a HEO or Moon or Mars need not be
> analog? Has anyone considered a digital mode such as WSJT
> for comms? I know for a fact people are running meteor
> scatter and EME using a single beam (albeit a long one) and
> 150 watts. This is not out of the reach of most hams and it
> is not non-viable communications mode... Heck the US Navy
> even ran RTTY in the 60's from Hawaii to Maryland as a
> normal mode of communications (yes it was big and wieldy, I
> just mentioned it as an aside).
>
> DE - KD1PE - Jack
>
>
>
> >> Why go with the minimal antenna gain?
> >> ... any antenna with a 3 db point that exceeds
> >> 6.5 degrees is just wasting transmitter power.
> >
> > I think that would be about a 24 dB gain
> antenna.? Pretty big
> > and would take some careful alignment...? Kinda
> like a realy big
> > EME array
> >
> >> Just remember what an Oscar 10 station took
> >> to have reliable communications, At Apogee
> >> it was only 35,000 miles away, the Moon is ...]
> >> [250,000 miles]
> >
> > Which is 7 times farther, squared or 50 times more
> power (about
> > 17 dB).
> >
>
>
------------------------------
Message: 10
Date: Thu, 2 Jul 2009 08:32:09 -0700 (PDT)
From: MM <ka1rrw@xxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: amsat-bb@xxxxx.xxxx kg4zlb@xxxxx.xxx
Message-ID: <264959.33056.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Of course, lets get more Universities involved and build more Leos satellites
to fill those small ballast spots on new satellites.
The Moon option could be cheaper than a HEO's, if we can get it in as Public
Relations NASA project. The cost to get a ride on a HEO satellite is multiple
millions just for the ride into space. Amsat paid over a million dollars just
to ride a Prototype Rocket (AO-4). If you want to ride a Non-prototype rocket
to high orbit, add another 20 million. Cheap High orbit rocket rides are few
and far between. The Moon is the most affordable ride option this decade.
20 years ago NASA was looking for ballast for the TDRS satellites. We had the
opportunity to put a ham project on a few GEO satellites and missed the
opportunity. Lets not miss the Moon.
http://www.marexmg.org/fileshtml/ArissRebuild.html
--- On Thu, 7/2/09, David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx> wrote:
> From: David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx>
> Subject: [amsat-bb] Re: The Moon is our Future
> To: amsat-bb@xxxxx.xxx
> Date: Thursday, July 2, 2009, 11:15 AM
> On the contrary, we need more LEO's
> to augment and replace the existing
> aged fleet.
>
> Whilst AMSAT works on the HEO's lets put some of our
> efforts towards the
> Universities who seem to regularly put up 2/70 satellites!
>
> --
> David
> KG4ZLB
> www.kg4zlb.com
>
>
>
> Jack K. wrote:
> > I heard the same things when the first HEOs went up.
> It takes to much
> > money, it takes to much specialized equipment, it
> takes to much
> > knowledge, it is for elitists only... The bottom line
> is a LOT of hams
> > used them and it took some ingenuity, some new
> equipment, and yes we
> > all had to learn now things to use them. the bottom
> line is they
> > worked and worked well... My suggestion is quit
> looking at pitfalls
> > and problems as reasons not to do something, but as
> opportunities to
> > learn to accomplish new things (or improved
> communications anyway) and
> > move forward... We can put up all the leos we want,
> but until someone
> > makes something like B. Bruninga's cell concept work,
> we are only
> > going to have more of the same, We don't need more of
> the same!
> >
> > DE - KD1PE
> >
> >
> > ----- Original Message ----- From: <kd8bxp@xxx.xxx>
> > To: <bruninga@xxxx.xxx>;
> "'Joe'" <nss@xxx.xxx>;
> "'MM'" <ka1rrw@xxxxx.xxx>
> > Cc: "'Jack K.'" <kd1pe.1@xxxxx.xxx>;
> <amsat-bb@xxxxx.xxx>;
>
> > <kg4zlb@xxxxx.xxx>
> > Sent: Thursday, July 02, 2009 8:28 AM
> > Subject: Re: [amsat-bb] Re: The Moon is our Future
> >
> >
> >
> >
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx.
> 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: 11
Date: Thu, 02 Jul 2009 15:43:22 +0000
From: Nigel Gunn G8IFF/W8IFF <nigel@xxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: amsat-bb@xxxxx.xxx
Message-ID: <4A4CD59A.8010306@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
The Chinese are going to get there first.
David - KG4ZLB wrote:
> Just a question but if you do not think the US got to the Moon in 1969
> and neither do you think they will get back to the Moon in 2012, how do
> you propose seeing an amateur repeater on the Moon?
------------------------------
Message: 12
Date: Thu, 2 Jul 2009 15:50:21 +0000
From: kd8bxp@xxx.xxx
Subject: [amsat-bb] Re: The Moon is our Future
To: "Nigel Gunn G8IFF/W8IFF" <nigel@xxxxx.xxx>,
amsat-bb-bounces@xxxxx.xxxxxxxxxxxxx@xxxxx.xxx
Message-ID:
<750219272-1246549795-cardhu_decombobulator_blackberry.rim.net-
1300463148-@xxxxxxx.xxxx.xxxx.xx.xxxxxxxxxx>
Content-Type: text/plain; charset="utf-8"
I don't think man will ever walk on the moon. And I really didn't want to
start a whole thing on this -
Someone said that a man would have to roll out an antenna for a amatuer
project - I just don't think that will ever happen
A small robotic rover could do it but then you are talking expensive unless
nasa was willing to give "us" time on a rover that was going to do experiments
for nasa
LeRoy, KD8BXP
http://www.HamOhio.com
------Original Message------
From: Nigel Gunn G8IFF/W8IFF
Sender: amsat-bb-bounces@xxxxx.xxx
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: The Moon is our Future
Sent: Jul 2, 2009 11:43 AM
The Chinese are going to get there first.
David - KG4ZLB wrote:
> Just a question but if you do not think the US got to the Moon in 1969
> and neither do you think they will get back to the Moon in 2012, how do
> you propose seeing an amateur repeater on the Moon?
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. 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 on the Now Network? from my Sprint? BlackBerry
------------------------------
Message: 13
Date: 02 Jul 2009 10:52:11 -0500
From: tosca005@xxx.xxx
Subject: [amsat-bb] Re: The Moon is our Future
To: amsat-bb@xxxxx.xxx
Message-ID: <Prayer.1.0.16.0907021052110.27026@xxxx.xx.xxx.xxx>
Content-Type: text/plain; format=flowed; charset=ISO-8859-1
On Jul 2 2009, kd8bxp@xxx.xxx wrote:
> Don't want to get a whole new thing started here but - I don't think we
> ever went to the moon in 1969 and I don't think we will ever goto the
> moon - in 2012 or whenever they proposed a "return" to the moon
With that level of disbelief I can certainly see why you are predisposed to
discount the possibility of a moon-based transponder.
> I would love to see an amatuer repeater on the moon thou - from my
> understanding EME is expensive to do, so I think it would leave most of
> us out
Not necessarily. Remember, with conventional EME, you send as large a
signal as you can muster towards the moon, incur huge path losses along the
way, then incur a huge loss because the moon is a very imperfect reflector
of RF energy, then incur the huge path loss back from moon to earth.
With a moon-based repeater, you send as large a signal as you can muster
towards the moon, incur the same path loss from earth to moon; BUT, THEN
you enlarge the signal with a gain antenna at the repeater, and then have a
sensitive receiver that can detect and amplify the signal. The repeater
then transponds the signal to a different frequency band, amplifies it as
much as equipment weight and power availability allow, transmit it through
a gain antenna, and only THEN incur the huge path loss from moon to earth.
Because the path loss is only in a single direction, and instead of an
inefficient (lossy) passive reflector, you have gain antennas for reception
and transmission, plus amplification on receive and on transmit, the net
earth station requirements should be much less than conventional EME.
That's not to say it would be easy, just that it should be easier than
conventional EME in terms of station requirements on earth. As has been
mentioned numerous times already, the station requirements for the space
end of the system are enormously more difficult than anything we've ever
tackled so far with either LEO or HEO satellites.
But there's no harm in DISCUSSING the idea, and learning about the pitfalls
and possibilities as part of the discussion. Even if it never comes to
pass, we should all be a bit more knowledgeable after having had the
discussion.
As far as the dreaming goes, wouldn't an L/S transponder be better than a
V/U or U/V transponder? Granted, the path loss is greater, but the antenna
gain is easier to produce...
While I am a firm believer in the KISS principle (Keep It Simple, Stupid!),
I am getting a little tired of hearing people complain endlessly about the
downfall of AO-40 being due to its complexity. Uhh, the downfall of AO-40
was human error, which will ALWAYS be an issue. The only reason that AO-40
was ever usable at all was BECAUSE of its complexity, i.e., the redundancy
of multiple transponders that could be switched into place after initial
failures, etc. OF COURSE, a mission to the moon needs to be as light and
compact as it can be made, and therefore much simpler than AO-40, but due
to the harsh environment in which it would be asked to operate, it needs to
be as complex as necessary to get the job done, i.e. not as simple as AO-10
or AO-13.
73 de W0JT
AMSAT-NA LM#2292
------------------------------
Message: 14
Date: Thu, 2 Jul 2009 12:04:45 -0400
From: "Robert Bruninga" <bruninga@xxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
To: <amsat-bb@xxxxx.xxx>
Message-ID: <7D94BE0957254318B932FC445AB9B4D6@xxxxx.xxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
> But doesn't it have to be above ground?
> Yes the moon is dry and probably the
> poorest conducting dirt there is, But
> just like on Earth it can't be laying
> on the ground yes?
Good question...
Even if the ground was a perfect reflector and conductor, then
the antenna would only have to be 19" above the ground at 2
meters. Next consider that the moon is rock and extremely
dry... And rock has about 1/1000 the conductivity of moist
soil... So where the "true" reflection in the ground of the
moon is surely many feet down. So sitting it on the ground" of
the moon is probably 99% as effective as trying to hang it 19"
up.
> Robert Bruninga wrote:
>
>
> BUT one easy way to get gain is to use just a long
coaxial gain
> cable. I think it takes about 22 feet of coaxial dipole
> elements at 2 meters to give about 6 dB of gain. So
laying down
> 6 dB gain segments on the rock of the moon is as easy as
> unrolling a spool of cable. Unrolling 8 of these with
the right
> spacing could yield about 17 dB.
>
> Of course this woiuld only point straight up, so it
would need
> to be on a moon base in the middle of the earth facing
side.
> But since there is a lot of interest in moon bases near
the
> poles where there might be water, then a similar array
of layed
> down coaxial cable arrays could be phased horizontally
to point
> at earth. Actually, just about any direction can be
obtained
> with the right spacing.
>
> ONLY problem of course is there has to be someone with
legs to
> roll out the cables.
>
> Just a thought.
> Bob, WB4APR
>
>
> ________________________________
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 8.5.375 / Virus Database: 270.13.2/2214 -
> Release Date: 07/02/09 05:54:00
>
>
>
>
------------------------------
Message: 15
Date: Thu, 2 Jul 2009 17:19:56 +0100
From: Fabiano Moser <fabianomoser@xxxxx.xxx>
Subject: [amsat-bb] How you do DOPPLER correction in Linear
Transponders?
To: amsat-bb <AMSAT-BB@xxxxx.xxx>
Message-ID:
<bf2deb8f0907020919l789ae07di29d27cd767bb0a43@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Dear friends,
We know that some Satellite Operators use diferent system to doppler
control.
For Linear Transponder
1) Adjust uplink and downlink automatic by CAT? (Not always woks, some times
I?m up or down from the computer adjust)
2) Adjust uplink and downlink manual
3) Keep Uplink fixed and adjust only the Downlink frequency.
What is the more indicate method to use?
FT-847 have knob to adjust Uplink without change downlink VFO, and I?m using
it to keep my voice in downlink at same downlink much I can.
But I know some operators use fixed uplink.
How you do?
--
73
Fabiano Moser CR7/PY5RX
ARISS-PORTUGAL (Amateur Radio on the International Space Station)
Representative at Teleconference and Portugal Telebridge Coordinator.
AMRAD/AMSAT-CT
http://www.amrad.pt/ariss.php
"There is no great talent without great will. (Honor? de Balzac)"
------------------------------
Message: 16
Date: Thu, 2 Jul 2009 16:23:59 +0000
From: kd8bxp@xxx.xxx
Subject: [amsat-bb] Re: The Moon is our Future
To: tosca005@xxx.xxxx amsat-bb-bounces@xxxxx.xxxx amsat-bb@xxxxx.xxx
Message-ID:
<514496195-1246551814-cardhu_decombobulator_blackberry.rim.net-
1258048420-@xxxxxxx.xxxx.xxxx.xx.xxxxxxxxxx>
Content-Type: text/plain; charset="utf-8"
I understand completely how EME works, and understand the losses - I am even
in favor of putting a repeater up on the moon if a way could be found to do it
-
Someone in the group and had something about a man would have to roll out a
large antenna - since I believe that no man has ever set foot on the moon I
find it hard to believe that a man will ever roll out an antenna
IMHO a robotic device of some kind would be better suited to doing it - but
then you have the cost factor weighting in
I just don't think any man or woman for that matter will ever walk on the moon
or ever has
Yes I am a very skepical person, and I am wrapped in a lot of contridictions
in my own right
- most of my skepicalism does lie in and around Nasa and the space program as
a whole -
And again this is just my opion. We as a whole nation spend billions on a
space program - as get very little in return. We keep servicing an ageing
fleet of shuttles and nothing really new is coming from the minds of Nasa. I
am skepical and a nonbelieve when it comes to the moon.
But I do agree talking about it and some of the ideas on how to over come the
losses and power requires maybe the only way anything ever will happen
LeRoy, KD8BXP
http://www.HamOhio.com
Sent on the Now Network? from my Sprint? BlackBerry
-----Original Message-----
From: tosca005@xxx.xxx
Date: 02 Jul 2009 10:52:11
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: The Moon is our Future
On Jul 2 2009, kd8bxp@xxx.xxx wrote:
> Don't want to get a whole new thing started here but - I don't think we
> ever went to the moon in 1969 and I don't think we will ever goto the
> moon - in 2012 or whenever they proposed a "return" to the moon
With that level of disbelief I can certainly see why you are predisposed to
discount the possibility of a moon-based transponder.
> I would love to see an amatuer repeater on the moon thou - from my
> understanding EME is expensive to do, so I think it would leave most of
> us out
Not necessarily. Remember, with conventional EME, you send as large a
signal as you can muster towards the moon, incur huge path losses along the
way, then incur a huge loss because the moon is a very imperfect reflector
of RF energy, then incur the huge path loss back from moon to earth.
With a moon-based repeater, you send as large a signal as you can muster
towards the moon, incur the same path loss from earth to moon; BUT, THEN
you enlarge the signal with a gain antenna at the repeater, and then have a
sensitive receiver that can detect and amplify the signal. The repeater
then transponds the signal to a different frequency band, amplifies it as
much as equipment weight and power availability allow, transmit it through
a gain antenna, and only THEN incur the huge path loss from moon to earth.
Because the path loss is only in a single direction, and instead of an
inefficient (lossy) passive reflector, you have gain antennas for reception
and transmission, plus amplification on receive and on transmit, the net
earth station requirements should be much less than conventional EME.
That's not to say it would be easy, just that it should be easier than
conventional EME in terms of station requirements on earth. As has been
mentioned numerous times already, the station requirements for the space
end of the system are enormously more difficult than anything we've ever
tackled so far with either LEO or HEO satellites.
But there's no harm in DISCUSSING the idea, and learning about the pitfalls
and possibilities as part of the discussion. Even if it never comes to
pass, we should all be a bit more knowledgeable after having had the
discussion.
As far as the dreaming goes, wouldn't an L/S transponder be better than a
V/U or U/V transponder? Granted, the path loss is greater, but the antenna
gain is easier to produce...
While I am a firm believer in the KISS principle (Keep It Simple, Stupid!),
I am getting a little tired of hearing people complain endlessly about the
downfall of AO-40 being due to its complexity. Uhh, the downfall of AO-40
was human error, which will ALWAYS be an issue. The only reason that AO-40
was ever usable at all was BECAUSE of its complexity, i.e., the redundancy
of multiple transponders that could be switched into place after initial
failures, etc. OF COURSE, a mission to the moon needs to be as light and
compact as it can be made, and therefore much simpler than AO-40, but due
to the harsh environment in which it would be asked to operate, it needs to
be as complex as necessary to get the job done, i.e. not as simple as AO-10
or AO-13.
73 de W0JT
AMSAT-NA LM#2292
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. 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@xxxxx.xxx. 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 4, Issue 307
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