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CX2SA > SATDIG 11.12.17 18:40l 844 Lines 33158 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. Re: Behavior on FM Satellites (ka9p@xxx.xxxx
2. Re: Behavior on FM Satellites (Glenn Miller - AA5PK)
3. Re: Rocket Lab Launch Tomorrow (B J)
4. Re: Rocket Lab Launch Tomorrow (Wendy and Terry Osborne)
5. Re: Rocket Lab Launch Tomorrow (Wendy and Terry Osborne)
6. The Unofficial AMSAT D-STAR net. (Ted)
7. Re: Moxon vs. Turnstile (Rico van Genugten)
8. Re: Behavior on FM Satellites (Roy Dean)
9. Re: High Speed Telemetry, SDR#, and RTS/SDR (Scott) (Burns Fisher)
10. Re: Behavior on FM Satellites (Burns Fisher)
11. Re: Moxon vs. Turnstile (Bob)
----------------------------------------------------------------------
Message: 1
Date: Sun, 10 Dec 2017 22:28:46 -0500
From: ka9p@xxx.xxx
To: k8bl@xxxxxxxxx.xxxx daron@xxxxxx.xxxx hamdan@xx.xxxxxx.xxxx
amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Behavior on FM Satellites
Message-ID: <160439e23dd-170c-32cfd@xxxxxxxxxxxxx.xxx.xxxxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Thanks Bob, no attempt to hide it - it is my email address right at the top.
?
Scott ka9p
?
In a message dated 12/10/2017 9:27:28 PM Central Standard Time,
k8bl@xxxxxxxxx.xxx writes:
?
Please include your Call when posting so we have a clue who you are.
?
TNX/73, ? ? ?Bob ?K8BL
From: Scott via AMSAT-BB <amsat-bb@xxxxx.xxx>
To:daron@xxxxxx.xxxx hamdan@xx.xxxxxx.xxxx amsat-bb@xxxxx.xxx
Sent: Sunday, December 10, 2017 10:05 PM
Subject: Re: [amsat-bb] Behavior on FM Satellites
I've got to go with the crowd that thinks poor operating needs to be called
out, particularly on the FM birds.
?
The ARRL has called out bad operating publicly in QST since Hiram Percy
Maxim's "The Old Man" rants (their words, not mine) - feedback is a gift -
and if folks don't call it out, it can't improve.
?
I won't go into the issue of old timers repeatedly chatting on busy FM birds
- but will point out there are a number that very patiently wait and listen,
and with a very potent signal call newcomers that are trying to have a first
QSO or two, making the new guy very happy and setting a good example for
everyone.?
?
For those that shy from social media - if you were to look - you'd find DX
operators severely discouraged by rotten operating, and being fairly vocal
about why they don't think it's worth the effort. ?Adrian's post is yet
another example of the same thing.
?
You can't shrug off what's happening with "the kids are new." The kind of
behavior that one wrote about, and that I listened to, was several operators
in a row calling without anyone waiting for the station called to
acknowledge the calling operator. ?Lack of situational awareness is a kind
description of it.
?
Public shamming of a new guy getting his feet wet probably isn't the way to
go, but Paul didn't seem to suggest that except as a last resort. ?Those FM
birds are a very scarce resource, put up there by some very dedicated people
that spent alot of time and effort to make it happen. They are often
available for less than an hour a day each to the entire ham population.
?
People need to actively reach out to folks that need help, in an encouraging
way where it's innocent enough, and in a more direct way where it's
thoughtless or worse.
?
And we probably have to ask ourselves how it is that new comers show up with
so little an idea about what's expected. ?I can't imagine that happening
with anyone from Matt's radio club for example, but if you're encouraging
folks to try satellites, make sure you educate them about how to go about
it, beyond buying an HT and an Arrow and pointing it up.
?
Rant over. ?TOM
?
In a message dated 12/10/2017 5:55:27 PM Central Standard Time,
daron@xxxxxx.xxx writes:
?
Thanks Bernie,
I think you hit most of the highpoints. All operating is about courtesy, it
should be a highlight for us at all times. However please remember that
amateur radio operators are in the hobby for different reasons.
Some folks hang works of art and family photos on the wall, some folks like
certificates. Some folks like to have a conversation on the radio, some
folks prefer to exchange only callsign, grid and signal and do not wish to
talk further. Some folks might be very well technologically connected and
choose (or not) to use that connectivity for amateur radio planning, while
others may prefer to use amateur radio without being dependant on social
media. Some folks sit in a hamshack with multiple radios, computer access,
tracking systems and 'plan' their contacts based on a footprint...others
stand in the yard with a yagi and two handhelds and just work whomever comes
up.
I'm not a contester, but I sure like to pick up a new grid square and more
importantly as one who has roved and done satellite work, I like to share
them when I can be helpful. The satellites are a limited resource, we need
to take turns and let others in.
There have been west coast passes where I've listened to the downlink and
I'm the ONLY one on the pass. I've had passes where I could visit with
someone a few states away for most of the pass, stopping between comments to
ask if anyone else wants in. And I've had passes where I tried for 5
minutes and couldn't squeak my callsign in.
For the most part I think we're all willing to play nice, but certainly we
need a reminder and there is no doubt we need to continue educating people
how to use satellites.
73
Daron N7HQR CN74
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Bernie
> and Cheryl
> Sent: Sunday, December 10, 2017 3:27 PM
> To: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] Behavior on FM Satellites
>
> Dear Folks:
>
> I certainly don't want to argue with the central premise, i.e., that
> when there's a rare grid square, it is good operating practice to back
> off of the bird and let everyone have a crack at working the "DX".
> Neither do I have a problem with good operating practice dictating
> that people not hog the bird (as has been described by Paul and other
> posters). I do have a problem with public shaming, especially if not
> preceded with a congenial email suggesting that the operator in
> question give people a chance. Most folks have their email addresses on
QRZ.com.
>
> The important thing to remember is that AMSAT hasn't published (to my
> knowledge) a rule stating that /only/ certain types of QSO's can occur
> on the FM satellites. I just looked at the website and there is a
> section called "Working Your First Satellite" and I don't see anything
> on there like that. The section on "Communications Satellites" has
> nothing like that either. Unless the control operators of the
> satellite (e.g., AO-91) made a decision in that vein, then the bird is
> open to all comers.
>
> Paul's post mentioned that the FM birds open up the hobby to a lot of
> people. That means the FM birds are going to have new people on them,
> and I think good operating practice indicates that people are welcomed
> on satellites, and if they make a mistake, the "suggestion" to improve
> their operating practice occurs in such a way that they aren't shamed,
> i.e., a tasteful email or perhaps even a snail mail.
>
> His post also mentioned that he monitored Twitter and took some other
> steps while preparing for the pass. I have to be honest and say I'm
> not a big social media person. I only opened up a Facebook page last
> year, and don't really know or care to know how to get on Twitter.
> Other than checking when AOS occurs, I typically don't do that much
> preparation for a pass. I don't think that disqualifies me from being
> able to operate on the birds. Like I said above, I will back off if
> I'm aware that there's a rare grid square on there, but I don't always
> know that's the case. All of us are coming within the footprint of
> the bird at different times, and so the newest person in the footprint
> won't always know what's happening at that moment.
>
> I guess the reason why this thread affected me to the point that I
> felt the need to reply is that I could see the situation degenerating
> very quickly into a war between two classes of operators. And then,
> given the nature of FM birds, it will be impossible for anyone to use
> them (it would be relatively easy for one angry operator to jam the
> bird during a pass), short of handing out CTSS tone codes to a select
> group. Until something like that happens, the satellites are a shared
> resource, and we're always going to be faced with folks who screw up
unintentionally.
> I'd just hate to see a flame war on the birds like we sometimes see on
> the internet.
>
> I'm not suggesting that satellite operating is "The Wild Wild West".
> I think it's just a matter of education, and courtesy.
>
> Admittedly, I'm on the FM birds rarely (I've operated AO-91 exactly
> once). I prefer the linear transponder satellites with their
> opportunity to have a real conversation as opposed to shouting out
> grid squares, but recognize (as Adrian points out in his post) that
> the setup for those birds requires more infrastructure that may be
> beyond a lot of people. However, I've been around a while (my first
> satellite QSO was on RS-10 back in 1994) and I remember how excited I
> was when I made my first QSO's, and know how devastated I would have
> been if someone called me out in a public forum because I did
> something wrong that I didn't know was wrong.
>
> All I'm asking for is that all operators in good faith be granted a
> modicum of courtesy, and we should be careful before deciding that
> someone is acting in bad faith. I love this hobby and my heart aches
> at some of the stuff I've heard on 75 meters, and on the local 2 meter
> repeaters. I'd hate to see that transfer over to the satellite
> community, which by and large, seems to be pretty professional.
>
> See you all on the birds. 73 de Bernie, KF0QS
>
_______________________________________________
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
Virus-free. www.avast.com
------------------------------
Message: 2
Date: Sun, 10 Dec 2017 21:49:04 -0600
From: "Glenn Miller - AA5PK" <aa5pk@xxxxxxxxxx.xxx>
To: <ka9p@xxx.xxx>, <k8bl@xxxxxxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Behavior on FM Satellites
Message-ID: <7DBFF8FC4F4E4137A979218E720A3A4F@xxxxxxx>
Content-Type: text/plain; format=flowed; charset="UTF-8";
reply-type=original
Scott via AMSAT-BB? Not seeing a call sign.
-----Original Message-----
From: Scott via AMSAT-BB
Sent: Sunday, December 10, 2017 9:28 PM
To: k8bl@xxxxxxxxx.xxx ; daron@xxxxxx.xxx ; hamdan@xx.xxxxxx.xxx ;
amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Behavior on FM Satellites
Thanks Bob, no attempt to hide it - it is my email address right at the top.
Scott ka9p
In a message dated 12/10/2017 9:27:28 PM Central Standard Time,
k8bl@xxxxxxxxx.xxx writes:
Please include your Call when posting so we have a clue who you are.
TNX/73, Bob K8BL
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 3
Date: Mon, 11 Dec 2017 04:58:00 +0000
From: B J <va6bmj@xxxxx.xxx>
To: Wendy and Terry Osborne <wandtosborne@xxxxx.xxx>
Cc: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
Message-ID:
<CAP7QzkNP1=_EvkDsBm=Tott_C=_TVmGJxgJ0=T+Onnt2Cu+Usw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset="UTF-8"
The latest Twitter feed says that the next launch window opens at 0130 UTC
tomorrow.
73s
Bernhard VA6BMJ @ CO96NG
On Mon, Dec 11, 2017 at 3:27 AM, Wendy and Terry Osborne <
wandtosborne@xxxxx.xxx> wrote:
>
>
> -----Original Message----- From: Wendy and Terry Osborne
> Sent: Monday, December 11, 2017 3:08 PM
> To: Selwyn Cathcart
> Cc: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
>
> Hi Selwyn,
>
> They shifted the streaming to:
> https://www.youtube.com/watch?v=hx52QKgF_HM&feature=youtu.be
> But they have closed the link down (for today?). Launch scrubbed for today.
> See: https://twitter.com/RocketLab
>
> Cheers,
> Terry
>
> -----Original Message----- From: Selwyn Cathcart
> Sent: Monday, December 11, 2017 12:09 PM
> To: osbornes@xxxxxxxx.xxx.xx
> Subject: RE: [amsat-bb] Rocket Lab Launch Tomorrow
>
> Hi Terry,
>
> Is the streaming link below correct - not a valid URL at this end??
>
> Ta
>
> Selwyn
>
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of B J
> Sent: Friday, December 8, 2017 02:52 PM
> To: Wendy and Terry Osborne
> Cc: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
>
> On 12/7/17, Wendy and Terry Osborne <osbornes@xxxxxxxx.xxx.xx> wrote:
>
>> Hi Launch Watchers,
>>
>> Rocket Lab?s second test launch will be streamed from about 01:15 UTC
>> tomorrow 8th December.
>> You can catch it here: http://www.rocketlab.co.nz/livestream
>>
>> Weather looks good so far.
>>
>
> <snip>
>
> Are there any updates? It's now after 0150 UTC and there's no video stream
> yet.
>
> 73s
>
> Bernhard VA6BMJ @ DO33FL
> _______________________________________________
> 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: 4
Date: Mon, 11 Dec 2017 14:45:41 +1300
From: Wendy and Terry Osborne <osbornes@xxxxxxxx.xxx.xx>
To: B J <va6bmj@xxxxx.xxx>
Cc: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
Message-ID: <72E0087808F9425F887DDE4206BEF0C6@xxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset=utf-8;
reply-type=original
Launch attempt scrubbed for today.
Weather and orbital traffic problems.
See: https://twitter.com/RocketLab
73,
Terry ZL2BAC
-----Original Message-----
From: B J
Sent: Monday, December 11, 2017 2:19 PM
To: Wendy and Terry Osborne
Cc: amsat-bb
Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
The video feed is active right now but there's no picture yet. It appears
that lift-off is scheduled for 0200 UTC today.
Go Electron! Go Rocket Lab!
73s
Bernhard VA6BMJ @ CO96NG
On Thu, Dec 7, 2017 at 2:45 AM, Wendy and Terry Osborne <
osbornes@xxxxxxxx.xxx.xx> wrote:
> Hi Launch Watchers,
>
> Rocket Lab?s second test launch will be streamed from about 01:15 UTC
> tomorrow 8th December.
> You can catch it here: http://www.rocketlab.co.nz/livestream
>
> Weather looks good so far.
>
> 73,
> Terry Osborne ZL2BAC
> _______________________________________________
> 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: 5
Date: Mon, 11 Dec 2017 15:08:22 +1300
From: Wendy and Terry Osborne <osbornes@xxxxxxxx.xxx.xx>
To: Selwyn Cathcart <zl2bjo@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
Message-ID: <5E73D1B18F3C435387820AFCD1EC3B2F@xxxxxxxxxx>
Content-Type: text/plain; format=flowed; charset=utf-8;
reply-type=original
Hi Selwyn,
They shifted the streaming to:
https://www.youtube.com/watch?v=hx52QKgF_HM&feature=youtu.be
But they have closed the link down (for today?). Launch scrubbed for today.
See: https://twitter.com/RocketLab
Cheers,
Terry
-----Original Message-----
From: Selwyn Cathcart
Sent: Monday, December 11, 2017 12:09 PM
To: osbornes@xxxxxxxx.xxx.xx
Subject: RE: [amsat-bb] Rocket Lab Launch Tomorrow
Hi Terry,
Is the streaming link below correct - not a valid URL at this end??
Ta
Selwyn
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of B J
Sent: Friday, December 8, 2017 02:52 PM
To: Wendy and Terry Osborne
Cc: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Rocket Lab Launch Tomorrow
On 12/7/17, Wendy and Terry Osborne <osbornes@xxxxxxxx.xxx.xx> wrote:
> Hi Launch Watchers,
>
> Rocket Lab?s second test launch will be streamed from about 01:15 UTC
> tomorrow 8th December.
> You can catch it here: http://www.rocketlab.co.nz/livestream
>
> Weather looks good so far.
<snip>
Are there any updates? It's now after 0150 UTC and there's no video stream
yet.
73s
Bernhard VA6BMJ @ DO33FL
_______________________________________________
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: Sun, 10 Dec 2017 21:29:50 -0800
From: "Ted" <k7trkradio@xxxxxxx.xxx>
To: "'Endaf Buckley'" <endaf99@xxxxx.xxx>, <AMSAT-BB@xxxxx.xxx>
Subject: [amsat-bb] The Unofficial AMSAT D-STAR net.
Message-ID: <001601d37241$111f48e0$335ddaa0$@xxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Nice chat tonight....kudos to Endaf
(keep it 'unofficial')
73, Ted
K7TRK
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Endaf
Buckley
Sent: Saturday, December 9, 2017 7:53 PM
To: AMSAT-BB@xxxxx.xxx
Subject: [amsat-bb] The Unofficial AMSAT D-STAR net.
The Unofficial AMSAT D-STAR net Monday at 03:30 UTC on Reflector 9C. This is
not affiliated with AMSAT and is just an informal round table type net
discussing all things satellite and more.
_______________________________________________
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: 7
Date: Mon, 11 Dec 2017 13:32:22 +0100
From: Rico van Genugten <rico.van.genugten@xxxxx.xxx>
To: KD4ZGW <kd4zgw@xxxxx.xxx>
Cc: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Moxon vs. Turnstile
Message-ID:
<CAJdc4v7f1er5a8LCQrCPNrmv_kHqLOTR8mW5wJie+Qgf0+O2jQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset="UTF-8"
Hi,
It depends on the type of turnstile and your application. I'm assuming that
you want to use the antenna in a fixed position pointing upwards, e.g. not
on a rotor. In this case you want the gain in upward direction to be as
_low_ as possible, since this means that you will have more gain at lower
elevations, where you need it most.
A turnstile antenna consisting of crossed dipoles and crossed reflector
elements has maximum gain in upward direction, but the gain and impedance
depend on the distance between radiating and reflecting elements. At about
37 cm or 14,5 inch spacing the impedance is 50 ohm, but the gain is way too
high to use as a non-directional antenna. Increasing the distance means
decreasing the gain, but also increasing the impedance, so you need some
kind of match to get a good swr.
A turnstile antenna consisting of crossed dipoles over a ground screen
gives a better pattern than one that uses reflector elements, but can be
more impractical. The gound screen needs to be fairly large in terms of
wavelengths (about 2 minimum), but if you can mount the antenna on the
ground this might not pose a problem. At a dipole hight of about 70 cm
(27,5 inch) above the ground screen you can get an impedance of about 100
ohms per dipole and a good pattern (yes, I did quite some simulations in my
quest for the ultimate stationary antenna. :)), which with some trickery
can give you a good 50 ohm match when the dipoles are combined, see the
eggbeater design which also shows an impedance of 100 ohm per loop.
A moxon antenna has quite some gain in upward direction and therefore less
gain at lower elevations, therefore I think it is unsuitable for stationary
use unless you are only interested in passes above 50 degrees, which rarely
happen and if so, for only a very short time. It is more suitable to be
mounted at a fixed elevation as a small directional antenna if you have
azimuth control but no elevation control. I have recently built a crossed
moxon mounted at 25 degrees on a simple azimuth-only rotator. Tests
conducted from the yard are promising so far. I'm putting it on the roof
when the weather improves, I will send an update to this list when I have
some results.
Then there is the option of building/buying an eggbeater antenna, but in my
opinion it is bulky, difficult to build and does not offer many advantages
over a turnstile.
I've experimented a lot with stationary antennas, but didn't have a lot of
success so far. The following properties of most stationary antennas are
hard to overcome:
- Most of the satellites currently active are linearly polarized and
unpredictable in orientation, so a ground-station antenna should be
circularly polarized or have changeable/switchable polarization. Most
stationary antennas are circularly polarized in upward direction, but
horizontally polarized at the horizon, resulting in deep signal fades when
the sat is at low elevations where the signal is lowest to begin with.
- Intelligibility of a signal depends on the SNR or Signal to Noise Ratio.
Omnidirectional antennas have lower gain and therefore lower signal levels,
but due to the omnidirectionality also have a higher noise floor,
decreasing the SNR even more than gain figures alone would indicate.
That doesn't mean stationary antennas are not useful:
- On linear sats you don't need the SNR required for FM-sats, so you might
have more luck with those.
- VHF downlinks are much easier to hear than UHF ones (for this and the
above reason you can forget about SO-50)
- As an uplink antenna they could be fine, usually hearing the sat is much
more difficult than getting in.
- FO-29 has circularly polarized antennas and therefore does not give as
much fading with an antenna that is linearly polarized at low elevations
- AO-85 and AO-91 have pretty strong downlinks, at higher elevations you
will hear them, at lower elevations you might too if you are lucky with
their orientation.
- Use good quality coax and connectors, preferably the least possible.
Don't use RG-58 for anything over 1 meter (40 inch).
Phew, maybe that is a bit more information than you ask for, good luck
experimenting. :)
Regards,
Rico van Genugten
PA3RVG
On Mon, Dec 11, 2017 at 3:37 AM, KD4ZGW <kd4zgw@xxxxx.xxx> wrote:
> What would be the better antenna: moxon or a turnstile?
>
> _______________________________________________
> 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: 8
Date: Mon, 11 Dec 2017 07:35:08 -0500
From: Roy Dean <royldean@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Behavior on FM Satellites
Message-ID:
<CADGPg2uprC5nR3Yo-jRYYGQA9Xr=Vy+ADEtKxT0J+02XmCZZNQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset="UTF-8"
Original email does indeed show call sign. Not sure why the quoted
message doesn't.
-Roy
K3RLD
> Scott via AMSAT-BB? Not seeing a call sign.
------------------------------
Message: 9
Date: Mon, 11 Dec 2017 08:01:29 -0500
From: Burns Fisher <burns@xxxxxx.xx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] High Speed Telemetry, SDR#, and RTS/SDR
(Scott)
Message-ID:
<CABX7KxXmSD5dNmW3jSHKHByhZJHDvKj+AgR15oB_-o-xG9kJXQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset="UTF-8"
All of the FM Foxes have high speed telemetry capability, but it has never
been used on AO-91. We did turn it on with AO-85 a few times, but that
was because this was the first Fox satellite and we wanted to test it.
AO-91 has no need for it. Fox-1Cliff and Fox-1D both have VGA-quality
cameras aboard, and high speed mode will be used to downlink pictures.
In other words, I don't know what you heard, but it was not high speed
data. Good reason it did not decode :-)
73,
Burns W2BFJ
On Thu, Nov 23, 2017 at 3:42 PM, Fred Castello <fredcastello@xxxxx.xxx>
wrote:
> Is anyone using this particular combination with the Fox 1 Telemetry
> Analysis Tool? Today on one of my good passes with AO-91 I believe it was
> transmitting high speed telemetry and it seemed no matter what combination
> I used, I could not get the tool to decode the high speed telemetry. I
> have no problem with the low speed Data Under Voice with this combination.
> I have always assumed that the high speed telemetry is on the same
> frequency as voice and low speed DUV. I would appreciate any thoughts
> anyone has as usual.
> Best Regards,
> Fred ? KF4FC
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Message: 10
Date: Mon, 11 Dec 2017 08:20:17 -0500
From: Burns Fisher <burns@xxxxxx.xx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Behavior on FM Satellites
Message-ID:
<CABX7KxWELCzO+0JVxqNTob=7xFZ2g08PjC8==pT94HeHcFaOiw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset="UTF-8"
I'll probably be sorry to get myself involved in this morass, but I think
it is worth saying/repeating: Many operators are in QRZ. If you think
they are behaving inappropriately why not send them a note rather than
calling out individuals on the bb? I know one of the operators mentioned
here and I did in fact send him a note. He had not received anything from
anyone previously. He was apologetic and unaware of his transgressions,
and also unaware of the bulletin board so he had not seen this
conversation. In addition, I know him to be a good guy and generally a
good operator on DX and a good contester and thus normally aware of rare
grids etc.
My points are: 1) Good people make mistakes. 2) Good operators are happy
to be corrected. 3) Calling out on a particular social medium does not
always reach the person in question. Why not assume they are of good faith
and try to make a friendly personal connection?
Back to lurk mode---73,
Burns W2BFJ
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Message: 11
Date: Mon, 11 Dec 2017 11:25:16 -0500
From: Bob <WB4SON@xxxxx.xxx>
To: KD4ZGW <kd4zgw@xxxxx.xxx>
Cc: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Moxon vs. Turnstile
Message-ID:
<CAPonRZ9776ncLetskXG_E6EJJmqqf0=zsUW-Go4mmE9J=PGWqw@xxxx.xxxxx.xxx>
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Probably best to start with the issue of antenna polarization. Most
terrestrial antennas are either horizontal (HF) or vertical (VHF/UHF FM)
polarized. Having a polarization match is critical, as a mismatch will
cause the signal to be about 30 dB weaker. 30 dB is more than enough to
take a signal that is "arm chair copy" to one that is below the noise
level. Your proposed Moxon could be installed for Horizontal, or Vertical
polarization.
Now lets think about satellite use. The satellite is orbiting above us,
and frequently has some sort of spin imparted on it. That spin may cause
the antenna polarization to change over time. Then as the satellite moves
across the sky there can be an apparent polarization change. If you were
talking about the Space Station, then the signal might be bouncing off of
metal parts. Very importantly for satellites, there can be a polarization
rotation or shift imparted by the ionosphere as well (at the frequencies we
use). The bottom line is the polarization of a satellite is often
unpredictable from moment to moment. This is why a more optimal antenna
will be one that has circular polarization. It doesn't matter how that
antenna appears to rotate up in space, you still pick it up down at the
ground. Deep fades are greatly reduced as a consequence. Your turnstile
antenna will be circularly polarized.
Next issue is omnidirectional vs. directional. The Moxon is a kind of beam
antenna, it is directional. Most of the signals you hear and your RF
energy will be going in the direction it is pointed. That's a good thing
as there is no reason to send your RF energy, or listen in directions that
you know you don't need to be. But the drawback is that you need some way
to move the beam around (a rotor). For satellite use it gets more
complicated, as not only do you need to know what compass direction to
point it toward (azimuth), you also need to know how far up in the sky to
point it (elevation). Beams with fewer elements (2 or 3) can be used for
satellites by pointing them at about 15 degrees above your local horizon
(say you have a small hill or houses nearby that might cause your local
horizon to be about 15 degrees (not unusual), then set your beam to about
30 degrees elevation). Having full azimuth and elevation control is ideal,
a requirement for beams with many elements, and can be real expensive for
the rotor and controller. Your Moxon could be used with a fixed elevation
and use an azimuth rotor only. Your turnstile antenna will be
omnidirectional -- no rotor required.
So now to what is "best". Best is whatever works for you and meets your
budget criteria. It might be a directional antenna on a fixed mount like a
camera tripod that is pointing at the location the satellite will be at 1/3
of the way through its orbit. Then you could move the antenna one time to
the point it will be at about 2/3 the way through its orbit. I do this
during Field Day -- it works every time -- but I'm generally only trying to
make one contact.
I've been using circular polarized omnidirectional antennas for 20 years.
No mechanical rotors and expensive controllers to worry about. Very
simple, very reliable. But you don't get something for nothing. They
don't have "gain" and they gradually shift from circular polarization to
horizontal at the horizon. In practical terms, if a LED satellite has a 12
minute orbital path, I will be able to work it with excellent results for
about 4 minutes (near the top of the orbit) and marginal results for maybe
another 2 minutes. So I get about 1/2 the path.
If it were me, I'd go with the turnstile.
73, Bob, WB4SON
On Sun, Dec 10, 2017 at 9:37 PM, KD4ZGW <kd4zgw@xxxxx.xxx> wrote:
> What would be the better antenna: moxon or a turnstile?
>
> _______________________________________________
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> expressed
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> AMSAT-NA.
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> 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 12, Issue 328
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