| |
CX2SA > SATDIG 07.10.16 20:45l 779 Lines 29739 Bytes #999 (0) @ WW
BID : AMSATBB11324
Read: GUEST
Subj: AMSAT-BB-digest V11 324
Path: IW8PGT<CX2SA
Sent: 161007/1836Z @:CX2SA.SAL.URY.SOAM #:55091 [Salto] FBB7.00e $:AMSATBB11324
From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. Re: AO-07 (Joe)
2. NPOTA TR20 activation via satellite (Oct 7-8) (Clayton Coleman)
3. Re: Global Geo SATCOM system? (Scott)
4. Re: Global Geo SATCOM system? (Edward R Cole)
5. Re: Global Geo SATCOM system? (Robert Bruninga)
6. F.S. Funcube and Amsat pre amp (Michael)
7. Loss Between Right and Left Circular (Roger Cooper)
8. Re: AO-07 (Greg D)
9. LVB/Amsat computer interface via USB ===> SatPC32 (Rafael Pe?a)
10. Re: Loss Between Right and Left Circular (Greg D)
11. Re: Loss Between Right and Left Circular (Glen Zook)
12. Re: Loss Between Right and Left Circular (Paul Andrews)
13. Re: F.S. Funcube and Amsat pre amp (Michael)
----------------------------------------------------------------------
Message: 1
Date: Fri, 7 Oct 2016 09:25:37 -0500
From: Joe <nss@xxx.xxx>
To: JoAnne Maenpaa <k9jkm@xxxxxxx.xxx>
Cc: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] AO-07
Message-ID: <c1e4d67b-1492-b926-0162-291527c79580@xxx.xxx>
Content-Type: text/plain; charset=utf-8; format=flowed
I would if I had a decent station. I love stuff like this, trying to
learn why something is the way it is.
The only thing I can think of is solar weather conditions, Since I
should have clarified that I'm talking about Mode "A" here only.
Soo wondering if some ionospheric stuff is effecting the down ward path
signal.
OHHH COOL Idea! What a neat idea for a sat!?
A RBN reciever in orbit! and it downloads what it's hearing and just
like a regular RBN it also tells signal strengths. hmmmmm?
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 10/7/2016 9:17 AM, JoAnne Maenpaa wrote:
> This sounds like an excellent experiment for you to try and report your
results in an article for the AMSAT Journal!
>
> --
> 73 de JoAnne K9JKM
>
>
>
> ----- Original Message -----
> From: "Joe" <nss@xxx.xxx>
> To: "amsat-bb" <amsat-bb@xxxxx.xxx>
> Sent: Friday, October 7, 2016 9:11:03 AM
> Subject: [amsat-bb] AO-07
>
> I wonder if anyone has actually done any studies after all these years
> on propagation's through this bird. AO-07
>
> I find it in the past couple weeks soo interesting on how varied the
> level of signal strengths can be on very similar passes.
>
> Where one pass, vs another are almost identical, yet one will be full of
> stations, and the next one all I hear is my own CQ.
>
> BUT... that difference can be all made by just who is actually on the air.
>
> BUT.... then take two passes that are almost identical, and ignore all
> the other people, and pay attention to just your own signal, where on
> this pass my sig is soo weak that 90% of the time I'm hearing nothing,
> then next pass that is very similar I am actually moving the S meter the
> signal is sooo strong.
>
> And in theroy, this is all Line Of Sight communications, the losses from
> one pass vs another should be the same.
>
> Yes polarity can be an issue, but I cant see it being the reason for the
> whole pass duration.
>
> Very Interesting!
>
> Joe WB9SBD
------------------------------
Message: 2
Date: Fri, 7 Oct 2016 09:47:57 -0500
From: Clayton Coleman <kayakfishtx@xxxxx.xxx>
To: AMSAT-BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] NPOTA TR20 activation via satellite (Oct 7-8)
Message-ID:
<CAPovOwen7OPX9esF5qT7j5Yf2PizBs9aOTWyE+2QC3G_kqaM1Q@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Gabriel, NJ7H, and I will be operating satellites from some portions
of the El Camino Real de los Tejas National Historic Trail this
Saturday, October 8. You may hear us on late Friday evening (Oct 7.)
We'll be in EM21, my home grid.
El Camino Real de los Tejas:
https://www.nps.gov/elte/index.htm
Mission Tejas State Park:
http://tpwd.texas.gov/state-parks/mission-tejas
GIS Interactive Trail Viewer:
http://imgis.nps.gov/html/?viewer=nht
73
Clayton
W5PFG
------------------------------
Message: 3
Date: Fri, 7 Oct 2016 11:11:50 -0400
From: "Scott" <scott23192@xxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Global Geo SATCOM system?
Message-ID: <479FC4F2C9864E8DB767E1DC4BC4B00D@xxxxxxx>
Content-Type: text/plain; format=flowed; charset="UTF-8";
reply-type=original
>> Please tell me about your setup
The items involved and the order to do the setup are in this earlier post:
http://www.amsat.org/pipermail/amsat-bb/2016-October/060666.html
------------------------------------------------------------------------------
--
-----Original Message-----
From: Andrew Rich
Sent: Friday, October 07, 2016 3:21 AM
To: Scott
Cc: Amsat BB ; Peter Davies
Subject: Re: [amsat-bb] Global Geo SATCOM system?
Ok not you have got me REALLY interested
Please tell me about your setup
Andrew
> On 7 Oct 2016, at 15:28, Scott <scott23192@xxxxx.xxx> wrote:
>
> I have a couple of additional pieces of information to pass along on this
> topic as of tonight.
>
> As many are aware, the Outernet hardware "package" consists of a patch
> antenna, LNA, and unmarked SDR with bias-T enabled.
>
> Tonight I remembered that some time ago I could not resist buying a couple
> of the second (?) generation metal-case RTL-SDR dongles from rtl-sdr.com.
> I have been using one on my linux computer but the other one was unused.
> Remembering that these rtl-sdr dongles had 5v bias-T as an option, I took
> the unused one apart and soldered the appropriate pins to enable the
> bias-T. That allowed me to do a comparison with the unmarked SDR that
> came
> with the other Outernet items.
>
> Setting Outernet aside for a moment, I did an apples to apples comparison
> of the L-Band AERO signals coming from Inmarsat 4-F3. The difference in
> signal strength was obvious and substantial. The rtl-sdr gave me over
> 10db
> more SNR, so in addition to the 600 & 1200 AERO data streams, I could now
> easily decode the 10k AERO signals where there is a lot more (and more
> interesting) traffic.
>
> So with that test complete and fairly conclusive, I reconnected everything
> to the Raspberry Pi but with the rtl-sdr dongle this time. Not
> surprisingly, the L-Band Outernet signal was also greatly improved. Where
> my SNR figure had been around 3, with the rtl-sdr dongle it was varying
> between 6 & 8. Please keep in mind that I do not have a clear sky view,
> so
> take all of these findings with that in mind.
>
> A few minutes after powering up the Pi and seeing the improved SNR figure,
> content from the satellite started downloading. As you might expect, the
> rate seemed to be noticeably quicker than before.
>
> Imagine my surprise to see the first file arrive as a .tgz compressed
> archive that, when extracted, contained some amateur radio content! Here
> are the first few lines from the file that just arrived:
>
> ==========================
> OUTERNET>APRS:>OUTERNET file created Fri Oct 7 05:00:19 UTC 2016
> VI50CC>APRS,RS0ISS*,qAR,ZL4JL-6::RS0ISS :Hello ZL James G/day Mate
> RS0ISS>CQ,qAS,ZL1KM-H:>ARISS - International Space Station
> K6PKL>CQ,RS0ISS*,qAS,KK6RKY:=3748.51N/12112.44W-Solar powered, 20 watts
> j-pole {UIV32N}
> KK6OTJ-7>DE1QYT,RS0ISS*,qAS,KK6RKY:`.BJl tK\>CQ CQ CQ ALL LIVE OPERATORS
> PLEASE REPLY =
> KK6OTJ-7>DE1QYT,RS0ISS*,qAS,KK6RKY:`.BJl"@xx>CQ CQ CQ ALL LIVE OPERATORS
> PLEASE REPLY =
> KK6OTJ-7>DE1QYT,RS0ISS*,qAS,KK6RKY:`.BJl"cK\>CQ CQ CQ ALL LIVE OPERATORS
> PLEASE REPLY =
> RS0ISS>CQ,qAS,KK6RKY:>ARISS - International Space Station
> ==========================
>
> ... and it continued with similar APRS type traffic.
>
> So, if my finding is any example, if anyone would like to optimize their
> Outernet reception, or for that matter ANY L-band reception, you can do it
> without dedicating one of the expensive SDR's to this function. The
> metal-case rtl-sdr dongle with bias-T enabled was an excellent step up in
> performance for me.
>
> -Scott, K4KDR
>
> =============
> =============
>
> On Wed, Oct 5, 2016 at 6:51 PM, Robert Bruninga <bruninga@xxxx.xxx> wrote:
>
>> AMSAT tinkerers?
>>
>> OUTERNET is a free worldwide Geostationary Satellite downlink system
>> designed to bring content to remote areas all over the globe. They have
>> six geostationary birds covering the entire globe EVERYWHERE. All you
>> need
>> is a small 18? (or 36? in some very remote areas) to receive content via
>> your own home-made receiver based on a TV dongle and Rasberry Pi.
>>
>> Is there anyone on AMSAT-bb that is already receiving this content? We?d
>> like to hear about how easy it is to set up a receiver.
>>
>> We have some ideas on how this can be used to augment Ham radio in our
>> Emergency Response and remote operations missions. See
>> http://aprs.org/outnet.html
>>
>> Bob, WB4APR
------------------------------
Message: 4
Date: Fri, 07 Oct 2016 07:45:29 -0800
From: Edward R Cole <kl7uw@xxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Global Geo SATCOM system?
Message-ID: <201610071545.u97FjT9X012923@xxxxxxxxx.xxxxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
After Bob posted the info and links to Outernet I looked over the
equipment and the satellite footprints. Not clear to me if there
would be any reception at my latitude and longitude (60.688N, 151.331W).
From years past I recall how few ISS passes came above the southern
horizon far enough to any chance of contacts (max elev is 11-degrees
for about 12-min long pass). And ISS is in Leo orbit so its
constantly changing. A geo sat is fixed so you get - what you get
(if it is too far east or west of me that is "nothing"). Highest
elev angle for Geo-sat orbit is 21 degrees looking due south. Trees
(solid forest) set lower elev limit at about 9-degrees in all directions.
I used a 33-inch offset feed dish on AO-40 so that is available to
put up with suitable feed. The 8-dBi patch may have too wide a beam
pattern for use with such a dish. I wondered if using a cylindrical
short cavity with the patch might increase gain and narrow the beam
adequately? For 2.4G I used a six turn helical feed (RHCP).
Good info on the rtl-sdr. I gave one to my step-son which we were
unable to get good performance on VHF so maybe he would send it back
to me. I sent him a used RS HF receiver which is what he
wanted. Pretty sure the rtl-sdr is not in use (he was using Mac-OS
which further complicated and frustrated getting sw running); I have win-XP32.
73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
dubususa@xxxxx.xxx
------------------------------
Message: 5
Date: Fri, 7 Oct 2016 12:28:24 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: Edward R Cole <kl7uw@xxxxxxxxx.xxx>, amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Global Geo SATCOM system?
Message-ID: <61682024700469cc466de3c402152545@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
The http://aprs.org/outnet.html page now shows the OUTERNET coverage. It
is virtually worldwide...
Bob
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Edward R
Cole
Sent: Friday, October 07, 2016 11:45 AM
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Global Geo SATCOM system?
After Bob posted the info and links to Outernet I looked over the
equipment and the satellite footprints. Not clear to me if there would be
any reception at my latitude and longitude (60.688N, 151.331W).
From years past I recall how few ISS passes came above the southern
horizon far enough to any chance of contacts (max elev is 11-degrees for
about 12-min long pass). And ISS is in Leo orbit so its constantly
changing. A geo sat is fixed so you get - what you get (if it is too far
east or west of me that is "nothing"). Highest elev angle for Geo-sat
orbit is 21 degrees looking due south. Trees (solid forest) set lower
elev limit at about 9-degrees in all directions.
I used a 33-inch offset feed dish on AO-40 so that is available to put up
with suitable feed. The 8-dBi patch may have too wide a beam pattern for
use with such a dish. I wondered if using a cylindrical short cavity with
the patch might increase gain and narrow the beam adequately? For 2.4G I
used a six turn helical feed (RHCP).
Good info on the rtl-sdr. I gave one to my step-son which we were unable
to get good performance on VHF so maybe he would send it back to me. I
sent him a used RS HF receiver which is what he wanted. Pretty sure the
rtl-sdr is not in use (he was using Mac-OS which further complicated and
frustrated getting sw running); I have win-XP32.
73, Ed - KL7UW
http://www.kl7uw.com
"Kits made by KL7UW"
Dubus Mag business:
dubususa@xxxxx.xxx
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available to
all interested persons worldwide without requiring membership. Opinions
expressed are solely those of the author, and do not reflect the official
views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 6
Date: Fri, 7 Oct 2016 12:48:05 -0400
From: Michael <Mat_62@xxxxxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] F.S. Funcube and Amsat pre amp
Message-ID: <ce1f41cd-6ae5-68a0-b12c-c2863e9b0be3@xxxxxxx.xxx>
Content-Type: text/plain; charset=utf-8; format=flowed
Once again I find myself in the unfortunate situation of having to sell
some ham gear because of hardship in my family. I have a Funcube Dongle
Pro + and a short cable adapter that goes from the Funcube outlet to a
female F connector. Priced to sell quick at 105.00 which includes
shipping to anywhere in the lower 48 states. I also have an Amsat
broadband preamp that has never been used. There is some wear and tear
on the label to the preamp but it is still clear enough to determine the
input and output connections. The price on it is $35.00 dollars
including shipping to anywhere in the lower 48 states. I cannot claim
these items to be smoke free. There is absolutely no smoking in the
radio room but there is a smoker elsewhere in the house. I'm sorry but I
cannot handle any kind of international shipping at this time. PAYPAL
ONLY. Pictures can be sent if requested but these are two small items
and I guarantee them to work. If you would like you can check my seller
feedback on e-bay under w4hij. Stay tuned as their may be more stuff
coming down the line to be posted for sale. Please contact me off list
if you are interested.
Thank you and 73,
Michael, W4HIJ
------------------------------
Message: 7
Date: Fri, 7 Oct 2016 10:33:24 -0700
From: Roger Cooper <rogern3rc@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Loss Between Right and Left Circular
Message-ID:
<CAKpwybYCtHA8cTnKMHc4f8MB3UqcGJ6XS4gHW35DAkjs5yk-Cg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
About 10 years ago got interested in sat radio and bought a Left Circular
Quadrifilar Helix Antenna which got good review in QST. Didnt use it and
now retired and trying to get on sat. Evidently most ham sats are right
circular and depending on
what I read. there is a 30db OR 3db loss going from one circular
polarization to another. Which is it?
Thanks Roger N3RC
------------------------------
Message: 8
Date: Fri, 7 Oct 2016 10:39:55 -0700
From: Greg D <ko6th.greg@xxxxx.xxx>
To: Joe <nss@xxx.xxx>
Cc: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] AO-07
Message-ID: <57F7DDEB.4070108@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Hi Joe,
My recollection is that there were some informal propagation studies
done on the old RS-10/11 and RS-12/13 satellites. I found a few
references back in the Amsat archives. See:
http://www.amsat.org/amsat/articles/satgen/idx050.html
Good topic needing an update, even an informal one.
Greg KO6TH
Joe wrote:
> I wonder if anyone has actually done any studies after all these years
> on propagation's through this bird. AO-07
>
> I find it in the past couple weeks soo interesting on how varied the
> level of signal strengths can be on very similar passes.
>
> Where one pass, vs another are almost identical, yet one will be full
> of stations, and the next one all I hear is my own CQ.
>
> BUT... that difference can be all made by just who is actually on the
> air.
>
> BUT.... then take two passes that are almost identical, and ignore
> all the other people, and pay attention to just your own signal, where
> on this pass my sig is soo weak that 90% of the time I'm hearing
> nothing, then next pass that is very similar I am actually moving the
> S meter the signal is sooo strong.
>
> And in theroy, this is all Line Of Sight communications, the losses
> from one pass vs another should be the same.
>
> Yes polarity can be an issue, but I cant see it being the reason for
> the whole pass duration.
>
> Very Interesting!
>
> Joe WB9SBD
------------------------------
Message: 9
Date: Fri, 7 Oct 2016 13:41:07 -0400
From: Rafael Pe?a <pinoleronica@xxxxxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Cc: Rafael Pe?a <pinoleronica@xxxxxxx.xxx>
Subject: [amsat-bb] LVB/Amsat computer interface via USB ===> SatPC32
Message-ID: <BAY182-W71459B2356B29AA53DF217C6C60@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
I have acquired a Yaesu G-5500 rotor / controller along with LVB/Amsat
computer interface but for the sake of setup I cannot make it talk to
SatPC32. Manually, azimuth / elevation works just fine using both Yaesu
controller and LVB interface....LVB triggers the rotor just as the
controller does individually.
I read that SDX is the software to use with Yaesu GS-232a/b and compatible
controllers . So I run the SDX file which comes with the SatPC32 setup
file. This SDX file is in a folder within SatPC32.
When I turn on the Yaesu controller, the USB connected to LVB gets detected
by Windowz 10 and creates a COM8 automatically. I configured ServerSDX for
this COM#. I also configured the SatPC32 Rotor setup and select the Yaesu
Rotor (232). There are no more settings there to change. ServerSDX is
suppose to run upon launching SatPC32. It is suppose to send data to the
LVB so that rotor follows the satellite via program SatPC32. I do not see
this happening.
What am I missing? Any help is appreciated.
Rafael A Pe?aNN3RP
Washington, DC
------------------------------
Message: 10
Date: Fri, 7 Oct 2016 11:00:55 -0700
From: Greg D <ko6th.greg@xxxxx.xxx>
To: Roger Cooper <rogern3rc@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Loss Between Right and Left Circular
Message-ID: <57F7E2D7.50607@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Hi Roger,
Going from left to right, or right to left, with both sides being
circular is in that 30db loss realm. I recall it being more like 20db,
but once you get in that range, a few db either way kind of doesn't
matter. In practice it's not quite that bad, since in practice nothing
is perfectly circular, but, yeah, not a recipe for success.
Crossing circular (either handed) with linear is 3db, I believe. Or was
it 6? Anyway, not impossibly bad. Hopefully you also have a preamp at
the antenna, which will offset a lot of this. If not, I'd invest in
one, regardless of the polarization topic.
I have a pair of switchable beam antennas for satellite work. My
observation is that most of the newer satellites these days appear to be
linear, and I've noticed that while there appears to be some difference
between right vs left on the ground, crossed with their linear signals,
most of the time it's not fatal. Either can work for at least part of
the pass.
Bottom line is that you've got a workable antenna. Try it and see what
you get.
Greg KO6TH
Roger Cooper wrote:
> About 10 years ago got interested in sat radio and bought a Left Circular
> Quadrifilar Helix Antenna which got good review in QST. Didnt use it and
> now retired and trying to get on sat. Evidently most ham sats are right
> circular and depending on
> what I read. there is a 30db OR 3db loss going from one circular
> polarization to another. Which is it?
>
> Thanks Roger N3RC
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 11
Date: Fri, 7 Oct 2016 18:18:39 +0000 (UTC)
From: Glen Zook <gzook@xxxxx.xxx>
To: Greg D <ko6th.greg@xxxxx.xxx>, Roger Cooper <rogern3rc@xxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Loss Between Right and Left Circular
Message-ID: <1754291450.226573.1475864319800@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Theoretically, going from right hand to left hand circular polarization
results in an infinite loss. ?However, in practice, the loss is generally
around 20 dB although, in certain circumstances, it can be as high as 30 dB,
or more.
It is the same going between vertical polarization and horizontal
polarization. ?Theoretically infinite but in practice more like 20 dB.
Going from linear polarization to either left hand or right hand circular
polarization results in a 3 dB loss.
?Glen, K9STH?
Website: http://k9sth.net
From: Greg D <ko6th.greg@xxxxx.xxx>
To: Roger Cooper <rogern3rc@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Sent: Friday, October 7, 2016 1:00 PM
Subject: Re: [amsat-bb] Loss Between Right and Left Circular
Hi Roger,
Going from left to right, or right to left, with both sides being
circular is in that 30db loss realm.? I recall it being more like 20db,
but once you get in that range, a few db either way kind of doesn't
matter.? In practice it's not quite that bad, since in practice nothing
is perfectly circular, but, yeah, not a recipe for success.
Crossing circular (either handed) with linear is 3db, I believe.? Or was
it 6?? Anyway, not impossibly bad.? Hopefully you also have a preamp at
the antenna, which will offset a lot of this.? If not, I'd invest in
one, regardless of the polarization topic.
I have a pair of switchable beam antennas for satellite work.? My
observation is that most of the newer satellites these days appear to be
linear, and I've noticed that while there appears to be some difference
between right vs left on the ground, crossed with their linear signals,
most of the time it's not fatal.? Either can work for at least part of
the pass.
Bottom line is that you've got a workable antenna.? Try it and see what
you get.
------------------------------
Message: 12
Date: Fri, 7 Oct 2016 14:14:26 -0400
From: Paul Andrews <w2hro.fn20@xxxxx.xxx>
To: Greg D <ko6th.greg@xxxxx.xxx>
Cc: Roger Cooper <rogern3rc@xxxxx.xxx>, amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Loss Between Right and Left Circular
Message-ID:
<CAOsf+NRDB82hUvsbZ8xN4rmygGChrEOcKeOx69FrLkemTv2_vA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Roger / Greg,
Greg is correct the CubeSats appear to be mostly linear polarized.
Using a RHCP or LHCP polarized ground antenna will limit your
"satellite tumble" loss to 3db. I also have x-pol yagis and using CP
on CubeSats makes operation a little easier but you give up a minimum
of 3db on RX and TX However, satellite operation is not really weak
signal and there is usually plenty of link margin. I agree, using 2m
and 70cm preamps will greatly enhance your satellite experience.
I have used both switchable linear x-pol yagis and RHCP yagis on
CubeSats and FO-29 / AO-7. They both work - RHCP (circular) will
minimize the deep signal nulls as the satellite tumbles. Be careful,
I think FO-29 is a CP satellite so you need to pick the correct uplink
sense. Linear will be ok FO29.
This is the beauty of the handheld Arrow yagi. The human brain / ear
combination directs this low gain linear polarized yagi to exactly the
correct polarization everytime without the 3db CP penalty. The only
problem with the Arrow is that you need to be outside in the rain and
snow for every satellite pass. :) BTW - I have seen Arrow yagis
mounted on Az/El rotors but now you lose the polarization correction.
It's ham radio - try everything!
73 - Paul - W2HRO
On Fri, Oct 7, 2016 at 2:00 PM, Greg D <ko6th.greg@xxxxx.xxx> wrote:
> Hi Roger,
>
> Going from left to right, or right to left, with both sides being
> circular is in that 30db loss realm. I recall it being more like 20db,
> but once you get in that range, a few db either way kind of doesn't
> matter. In practice it's not quite that bad, since in practice nothing
> is perfectly circular, but, yeah, not a recipe for success.
>
> Crossing circular (either handed) with linear is 3db, I believe. Or was
> it 6? Anyway, not impossibly bad. Hopefully you also have a preamp at
> the antenna, which will offset a lot of this. If not, I'd invest in
> one, regardless of the polarization topic.
>
> I have a pair of switchable beam antennas for satellite work. My
> observation is that most of the newer satellites these days appear to be
> linear, and I've noticed that while there appears to be some difference
> between right vs left on the ground, crossed with their linear signals,
> most of the time it's not fatal. Either can work for at least part of
> the pass.
>
> Bottom line is that you've got a workable antenna. Try it and see what
> you get.
>
> Greg KO6TH
>
>
> Roger Cooper wrote:
>> About 10 years ago got interested in sat radio and bought a Left Circular
>> Quadrifilar Helix Antenna which got good review in QST. Didnt use it and
>> now retired and trying to get on sat. Evidently most ham sats are right
>> circular and depending on
>> what I read. there is a 30db OR 3db loss going from one circular
>> polarization to another. Which is it?
>>
>> Thanks Roger N3RC
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership.
Opinions expressed
>> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 13
Date: Fri, 7 Oct 2016 14:34:57 -0400
From: Michael <Mat_62@xxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] F.S. Funcube and Amsat pre amp
Message-ID: <3a6c917d-7442-1b71-acaf-bf4a662cf9d8@xxxxxxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
On 10/7/2016 12:48 PM, Michael wrote:
Both these items have now been spoken for. If something changes or falls
through I will let everyone know.
Thanks for your interest,
Michael, W4HIJ
> Once again I find myself in the unfortunate situation of having to
> sell some ham gear because of hardship in my family. I have a Funcube
> Dongle Pro + and a short cable adapter that goes from the Funcube
> outlet to a female F connector. Priced to sell quick at 105.00 which
> includes shipping to anywhere in the lower 48 states. I also have an
> Amsat broadband preamp that has never been used. There is some wear
> and tear on the label to the preamp but it is still clear enough to
> determine the input and output connections. The price on it is $35.00
> dollars including shipping to anywhere in the lower 48 states. I
> cannot claim these items to be smoke free. There is absolutely no
> smoking in the radio room but there is a smoker elsewhere in the
> house. I'm sorry but I cannot handle any kind of international
> shipping at this time. PAYPAL ONLY. Pictures can be sent if requested
> but these are two small items and I guarantee them to work. If you
> would like you can check my seller feedback on e-bay under w4hij. Stay
> tuned as their may be more stuff coming down the line to be posted for
> sale. Please contact me off list if you are interested.
> Thank you and 73,
> Michael, W4HIJ
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership.
> Opinions expressed
> are solely those of the author, and do not reflect the official views
> of AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Subject: Digest Footer
_______________________________________________
Sent via amsat-bb@xxxxx.xxx.
AMSAT-NA makes this open forum available to all interested persons worldwide
without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT member? Join now to support the amateur satellite program!
http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
End of AMSAT-BB Digest, Vol 11, Issue 324
*****************************************
Read previous mail | Read next mail
| |
