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CX2SA > SATDIG 05.07.08 04:13l 796 Lines 28436 Bytes #999 (0) @ WW
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Today's Topics:
1. Re: NASA's American Student Moon Orbiter... (D. Mynatt)
2. Re: source for LMR 400 UF connectors (Joseph Seibert)
3. Re: NASA's American Student Moon Orbiter... (Edward Cole)
4. Re: source for LMR 400 UF connectors (K7WIN)
5. Re: re best transceiver for sats (w7lrd(AT)comcast.net)
6. Re: source for LMR 400 UF connectors (Edward Cole)
7. Re: NASA's American Student Moon Orbiter... (i8cvs)
8. Re: re best transceiver for sats (Edward Cole)
----------------------------------------------------------------------
Message: 1
Date: Fri, 4 Jul 2008 10:03:23 -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>, "G0MRF David Bowman"
<g0mrf(AT)aol.com>, "AMSAT-BB" <amsat-bb(AT)amsat.org>
Message-ID: <F58D32B15B014AE980388135E114D3E1(AT)compaq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Probably a dumb question born of ignorance, but why isn't there more than 1
antenna on a sat, so that it's always pointing towards earth? Is Ion
propulsion for stabilization using solar power too far away to be practical
stabilization system?
----- Original Message -----
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
To: "G0MRF David Bowman" <g0mrf(AT)aol.com>; "AMSAT-BB" <amsat-
bb(AT)amsat.org>
Sent: Friday, July 04, 2008 7:42 AM
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> ----- Original Message -----
> From: <G0MRF(AT)aol.com>
> To: <amsat-bb(AT)amsat.org>
> Sent: Friday, July 04, 2008 3:44 AM
> Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
>>
>> In a message dated 04/07/2008 01:16:33 GMT Standard Time,
>> domenico.i8cvs(AT)tin.it writes:
>>
>> Hi Ed, KL7UW
>>
>> If we put AO40 at a distance of 400.000 km instead of 60.000 km
>> from the earth the increase of isotropic attenuation at 2400 MHz is
>> about 16 dB etc etc etc.........
>>
>>
>> Hi Ed / Dom
>>
>> On the other hand, if you were to reduce path loss by using 70cm as the
>> uplink band and 2m as the downlink the numbers begin to look quite
>> possible.
>
> Hi David, G0MRF
>
> Decreasing the frequency the absolute value of the isotropic attenuation
> decreases but the difference in path loss between 400.000 km and 60.000 km
> is the same 16.5 dB at any frequency so that to compensate for the above
> attenuation using lower frequencies you need bigger antennas both on the
> satellite and at the ground station.
>>
>> Also, if the satellite is orbiting the moon, then it's quite likely that
>> the attitude will be such that the experimental end of the satellite is
>> pointing at the moons surface. This probably also means that the
>> communication antennas are not pointing at the earth, so high gain
>> will not be possible.
>> Maybe 3 or 4dB is the limit.
>
> This is why it does not make sense to put a transponder orbiting around
> the moon just for the simple reason that it's very much more simple
> and cheap to put it into a HEO earth orbit.
>>
>> So how about 10W of 2m on the satellite and a passband that's say
>> 5kHz wide? Not good for SSB, but passable for CW or reasonable
>> speed coherent BPSK
>>
>> Regards
>>
>> David
>
> Only considering the 2 meters downlink suppose to put AO40 at 400.000
> km with the antennas pointing at the earth with low squint angle let say
> less than 10 degrees.
> The gain of the AO40 2 meters antennas was 10 dBi and we put your
> 10 watt on it.
>
> Suppose that your 2 meter antenna has a gain of 13 dBi and the overall
> noise figure of your receiving system is NF= 0,7 dB = 51 kelvin so that
> the noise floor into a CW passband of 500 Hz with the antenna looking
> at the moon (200 kelvin) is about -178 dBW
>
> Suppose that the station in QSO with you has a 70 cm EIRP capability to
> get the full 2 meters 10 watt from the transponder only for you and we
> can calculate it later on.
>
> 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 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.
>
> 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: Fri, 4 Jul 2008 08:37:43 -0700 (PDT)
From: Joseph Seibert <jsalaska(AT)yahoo.com>
Subject: [amsat-bb] Re: source for LMR 400 UF connectors
To: amsat-bb(AT)AMSAT.Org, Jim Danehy <jdanehy(AT)cinci.rr.com>
Message-ID: <106186.36586.qm(AT)web30206.mail.mud.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1
Hi Jim.
?? I've?purchased LMR cable and connectors from:
texastowers.com
cablexperts.com
frigidn.com?? (Frigid North Electronics)
?? I use LMR cable not only for my ham shack, but at the Public Radio station
where I work. I highly recommend th "EZ" type crimp on connectors. It's also
nice to have the "EZ" stripper and crimp tool too (but they're pretty
pricey!).
Joe- AL1F
Bethel, Alaska
--- On Fri, 7/4/08, Jim Danehy <jdanehy(AT)cinci.rr.com> wrote:
From: Jim Danehy <jdanehy(AT)cinci.rr.com>
Subject: [amsat-bb] source for LMR 400 UF connectors
To: amsat-bb(AT)AMSAT.Org
Date: Friday, July 4, 2008, 5:24 AM
Can someone give me the contact information for a source selling connectors
for
LMR products ?
Jim W9VNE
Cincinnati, Ohio
_______________________________________________
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: Fri, 04 Jul 2008 08:43:01 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
To: "i8cvs" <domenico.i8cvs(AT)tin.it>, "G0MRF David Bowman"
<g0mrf(AT)aol.com>, "AMSAT-BB" <amsat-bb(AT)amsat.org>
Message-ID: <200807041643.m64Gh2DX078539(AT)iris.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 05:42 AM 7/4/2008, i8cvs wrote:
>----snip----
>
>Only considering the 2 meters downlink suppose to put AO40 at 400.000
>km with the antennas pointing at the earth with low squint angle let say
>less than 10 degrees.
>The gain of the AO40 2 meters antennas was 10 dBi and we put your
>10 watt on it.
>
>Suppose that your 2 meter antenna has a gain of 13 dBi and the overall
>noise figure of your receiving system is NF= 0,7 dB = 51 kelvin so that
>the noise floor into a CW passband of 500 Hz with the antenna looking
>at the moon (200 kelvin) is about -178 dBW
>
>Suppose that the station in QSO with you has a 70 cm EIRP capability to
>get the full 2 meters 10 watt from the transponder only for you and we
>can calculate it later on.
>
>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 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.
>
>73" de
>
>i8CVS Domenico
Good example of path link analysis, keeping it simple!
But the trick is limiting input to four stations with a linear
transponder and they all running an equal uplink. Reality is this
doesn't happen so the shared portion of downlink power may and most
likely will be less with reduced S/N. My experience with AO-40 was
that to have a reasonably good SSB contact you needed at least S/N of
10-dB. In fact that resulted in a fairly weak signal which was
difficult to copy. 20-dB S/N made for arm-chair reception.
Not discussed were the 70cm uplink requirements. I suppose one could
run high power to achieve that. My AO-40 experience was running up
to 60w at a 16.5 dBdc antenna (18.6 dBic). Most of the time I was
good with about 5-10w if the satellite was lightly loaded. But with
high numbers of stations trying to operate I needed the full EIRP =
72x60 = 4320w or in dB: 18.6 + 47.8 = 66.4 dBW
My AO-40 mode-US station consisted of a FT-847+60w linear at the
antenna (M2-436CP42UG) for uplink. The 2.4 GHz downlink was a
33-inch dish with helix feed+MKU-232A2 preamp+Drake converter+FT-847
(on 123-MHz).
I'm not going to go into those calculations.
------------------------------
Message: 4
Date: Fri, 4 Jul 2008 09:51:24 -0700
From: "K7WIN" <k7win(AT)k7win.net>
Subject: [amsat-bb] Re: source for LMR 400 UF connectors
To: "'Jim Danehy'" <jdanehy(AT)cinci.rr.com>, <amsat-bb(AT)amsat.org>
Message-ID: <012f01c8ddf6$318b3880$94a1a980$(AT)net>
Content-Type: text/plain; charset="us-ascii"
Hi Jim,
I use LMR-400 and have found the best deal for connectors etc from the
following:
http://stores.ebay.com/Coax-Warehouse
Connectors (both male and female N type) for about $2 each and the crimping
tool for $25.
73, Jeff
K7WIN
> -----Original Message-----
> From: amsat-bb-bounces(AT)amsat.org [mailto:amsat-bb-bounces(AT)amsat.org]
On
> Behalf Of Jim Danehy
> Sent: Friday, July 04, 2008 6:25 AM
> To: amsat-bb(AT)amsat.org
> Subject: [amsat-bb] source for LMR 400 UF connectors
>
> Can someone give me the contact information for a source selling
> connectors for LMR products ?
>
> Jim W9VNE
> Cincinnati, Ohio
> _______________________________________________
> 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: Fri, 04 Jul 2008 17:08:57 +0000
From: w7lrd(AT)comcast.net
Subject: [amsat-bb] Re: re best transceiver for sats
To: "i8cvs" <domenico.i8cvs(AT)tin.it>, "Angus"
<angus(AT)young5769.freeserve.co.uk>, "AMSAT-BB" <amsat-
bb(AT)amsat.org>
Message-ID:
<070420081708.23824.486E59290006F9D600005D1022120592140B9D04C999(AT)comc
ast.net>
Content-Type: text/plain
My flavor for S band is- I use an old TS700A 2 meter xcvr with the
transmitter dissabled. It is so easy that when in the heat of battle to
accidently transmit into the dc. These and similar radios are fairly cheap
(less than $200), and depending on the dc cost is well worth it. The TS700
is now my stand alone, designated S band receiver.
73 Bob W7LRD
--
"if this were easy, everyone would be doing it"
-------------- Original message --------------
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
> ----- Original Message -----
> From: "Angus"
> To:
> Sent: Friday, July 04, 2008 1:41 PM
> Subject: [amsat-bb] re best transceiver for sats
>
> > Hi all,
> > just wondering what you think is the best transceiver or transceivers for
> the satellites. By this I mean to be able to TX and RX at the same time
> (covering from 144mhz, 70cm and 23cm), was thinking possibly something like
> the ICOM IC910 (with 23cm board added) so that USB downlink and LSB uplink
> can be done (can the TS2000 do this also). Or is it better to have 2
> seperate radios altogether, and use one for the uplink and one for the
> downlink?
> > Any thoughts or what do you think is the ultimate set up, doing quite well
> here with very simple FT817 and old FT480R but using transverter for 23cms.
> > regards
> > Gus M0IKB
>
> Hi Gus, M0IKB
>
> In my experience 2 separate radios altogheter, and use one for the uplink
> and one for the downlink is better !
>
> If you are doing quite well with very simple FT817 and FT480R and using 23
> cm transverters I suggest you do not change your setup.
>
> 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: Fri, 04 Jul 2008 09:28:52 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: source for LMR 400 UF connectors
To: <amsat-bb(AT)amsat.org>
Message-ID: <200807041728.m64HSqYF001575(AT)hermes.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
Lots of good reponse, Jim:
Like AL1F, I have gone to using only LMR-400 at work to replace
RG-8/RG-213 cabling. WE chose the crimp-style N-connectors at work
for speed of fabrication and have a local supplier for the connectors.
At home I still prefer the back-clamp style of N-connector. I buy
them from RF Parts (RFN-1002-iSI - male-N) at about $5.50 in
quantity. I have over twenty in my 2m-eme array working flawlessly
for ten years.
73 Ed - KL7UW
At 08:51 AM 7/4/2008, K7WIN wrote:
>Hi Jim,
>
>I use LMR-400 and have found the best deal for connectors etc from the
>following:
>http://stores.ebay.com/Coax-Warehouse
>
>Connectors (both male and female N type) for about $2 each and the crimping
>tool for $25.
>
>73, Jeff
>K7WIN
>
> > -----Original Message-----
> > From: amsat-bb-bounces(AT)amsat.org [mailto:amsat-bb-bounces(AT)amsat.org]
On
> > Behalf Of Jim Danehy
> > Sent: Friday, July 04, 2008 6:25 AM
> > To: amsat-bb(AT)amsat.org
> > Subject: [amsat-bb] source for LMR 400 UF connectors
> >
> > Can someone give me the contact information for a source selling
> > connectors for LMR products ?
> >
> > Jim W9VNE
> > Cincinnati, Ohio
> > _______________________________________________
> > 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: 7
Date: Fri, 4 Jul 2008 19:36:20 +0200
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
To: "D. Mynatt" <dave(AT)mynatt.biz>, "G0MRF David Bowman"
<g0mrf(AT)aol.com>, "AMSAT-BB" <amsat-bb(AT)amsat.org>
Message-ID: <001c01c8ddfc$79788de0$0201a8c0(AT)tin.it>
Content-Type: text/plain; charset="iso-8859-1"
Hi Dave,
The following article will show you how a "three axis stabilization wheels"
works on a satellite in order to keep the antennas constantly pointed toward
the earth.
Unfortunately due to the explosion many systems failed aboard of AO40 and
the above wheels never were running.
Only the magnetorquing system was used on AO40 to keep the Z axis spinning
and get the best compromise between the solar panels illumination and the
antenna pointing to the earth.
http://www.amsat.org/amsat/sats/phase3d/wheels/index.html
73" de
i8CVS Domenico
----- Original Message -----
From: "D. Mynatt" <dave(AT)mynatt.biz>
To: "i8cvs" <domenico.i8cvs(AT)tin.it>; "G0MRF David Bowman"
<g0mrf(AT)aol.com>;
"AMSAT-BB" <amsat-bb(AT)amsat.org>
Sent: Friday, July 04, 2008 6:03 PM
Subject: Re: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> Probably a dumb question born of ignorance, but why isn't there more than
1
> antenna on a sat, so that it's always pointing towards earth? Is Ion
> propulsion for stabilization using solar power too far away to be
practical
> stabilization system?
>
>
>
>
> ----- Original Message -----
> From: "i8cvs" <domenico.i8cvs(AT)tin.it>
> To: "G0MRF David Bowman" <g0mrf(AT)aol.com>; "AMSAT-BB" <amsat-
bb(AT)amsat.org>
> Sent: Friday, July 04, 2008 7:42 AM
> Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
>
>
> > ----- Original Message -----
> > From: <G0MRF(AT)aol.com>
> > To: <amsat-bb(AT)amsat.org>
> > Sent: Friday, July 04, 2008 3:44 AM
> > Subject: [amsat-bb] Re: NASA's American Student Moon Orbiter...
> >>
> >> In a message dated 04/07/2008 01:16:33 GMT Standard Time,
> >> domenico.i8cvs(AT)tin.it writes:
> >>
> >> Hi Ed, KL7UW
> >>
> >> If we put AO40 at a distance of 400.000 km instead of 60.000 km
> >> from the earth the increase of isotropic attenuation at 2400 MHz is
> >> about 16 dB etc etc etc.........
> >>
> >>
> >> Hi Ed / Dom
> >>
> >> On the other hand, if you were to reduce path loss by using 70cm as the
> >> uplink band and 2m as the downlink the numbers begin to look quite
> >> possible.
> >
> > Hi David, G0MRF
> >
> > Decreasing the frequency the absolute value of the isotropic attenuation
> > decreases but the difference in path loss between 400.000 km and 60.000
km
> > is the same 16.5 dB at any frequency so that to compensate for the above
> > attenuation using lower frequencies you need bigger antennas both on the
> > satellite and at the ground station.
> >>
> >> Also, if the satellite is orbiting the moon, then it's quite likely
that
> >> the attitude will be such that the experimental end of the satellite is
> >> pointing at the moons surface. This probably also means that the
> >> communication antennas are not pointing at the earth, so high gain
> >> will not be possible.
> >> Maybe 3 or 4dB is the limit.
> >
> > This is why it does not make sense to put a transponder orbiting around
> > the moon just for the simple reason that it's very much more simple
> > and cheap to put it into a HEO earth orbit.
> >>
> >> So how about 10W of 2m on the satellite and a passband that's say
> >> 5kHz wide? Not good for SSB, but passable for CW or reasonable
> >> speed coherent BPSK
> >>
> >> Regards
> >>
> >> David
> >
> > Only considering the 2 meters downlink suppose to put AO40 at 400.000
> > km with the antennas pointing at the earth with low squint angle let say
> > less than 10 degrees.
> > The gain of the AO40 2 meters antennas was 10 dBi and we put your
> > 10 watt on it.
> >
> > Suppose that your 2 meter antenna has a gain of 13 dBi and the overall
> > noise figure of your receiving system is NF= 0,7 dB = 51 kelvin so that
> > the noise floor into a CW passband of 500 Hz with the antenna looking
> > at the moon (200 kelvin) is about -178 dBW
> >
> > Suppose that the station in QSO with you has a 70 cm EIRP capability to
> > get the full 2 meters 10 watt from the transponder only for you and we
> > can calculate it later on.
> >
> > 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 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.
> >
> > 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: 8
Date: Fri, 04 Jul 2008 09:40:39 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: re best transceiver for sats
To: "AMSAT-BB" <amsat-bb(AT)amsat.org>
Message-ID: <200807041740.m64HedEh097029(AT)malik.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
Having started out on AO-10 with an IC-211 for 2m receive and a
TS-180S+mm432/28+50w amp for 70cm, then a FRG-100+IC215mod as rec
conv plus a TenTec Scout+DEMI 28/432+50w amp, Finally a FT-847, I'll
take the FT-847 every time! The IC-910 is probably comprable!
To avoid transmitting into your preamps or downconverters, modify the
radio for Rx only. I did that for the FT-847:
http://www.kl7uw.com/FT-847RXANT.htm
73 Ed - KL7UW
At 09:08 AM 7/4/2008, w7lrd(AT)comcast.net wrote:
>My flavor for S band is- I use an old TS700A 2 meter xcvr with the
>transmitter dissabled. It is so easy that when in the heat of
>battle to accidently transmit into the dc. These and similar radios
>are fairly cheap (less than $200), and depending on the dc cost is
>well worth it. The TS700 is now my stand alone, designated S band receiver.
>73 Bob W7LRD
>
>--
>"if this were easy, everyone would be doing it"
>
>-------------- Original message --------------
>From: "i8cvs" <domenico.i8cvs(AT)tin.it>
>
> > ----- Original Message -----
> > From: "Angus"
> > To:
> > Sent: Friday, July 04, 2008 1:41 PM
> > Subject: [amsat-bb] re best transceiver for sats
> >
> > > Hi all,
> > > just wondering what you think is the best transceiver or
> transceivers for
> > the satellites. By this I mean to be able to TX and RX at the same time
> > (covering from 144mhz, 70cm and 23cm), was thinking possibly
> something like
> > the ICOM IC910 (with 23cm board added) so that USB downlink and LSB uplink
> > can be done (can the TS2000 do this also). Or is it better to have 2
> > seperate radios altogether, and use one for the uplink and one for the
> > downlink?
> > > Any thoughts or what do you think is the ultimate set up, doing
> quite well
> > here with very simple FT817 and old FT480R but using transverter
> for 23cms.
> > > regards
> > > Gus M0IKB
> >
> > Hi Gus, M0IKB
> >
> > In my experience 2 separate radios altogheter, and use one for the uplink
> > and one for the downlink is better !
> >
> > If you are doing quite well with very simple FT817 and FT480R and using 23
> > cm transverters I suggest you do not change your setup.
> >
> > 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
>_______________________________________________
>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 334
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