Hi folks,
Regarding the 10m balloon tracking:
There's some interesting vertical 'Moxon' antenna designs here:-
http://www.moxonantennaproject.com/
If you can get hold of a fibreglass pole then it wouldn't be so difficult to
build a vertical - possibly even use wood,
There's even a very handy 'Moxon Generator', link here:-
http://www.moxonantennaproject.com/design.htm
Some of the builders report great DX if used near sea level, however I guess
this wouldn't be so good for tracking balloons as they have a low radiation
angle, you would probably get a better angle for the balloon if you were
away from the sea.
The antennas have a good F/B ratio, but a wide beamwidth, so again this may
make it more difficult for 'accurate' direction finding, but I'm sure would
give a general idea of the direction.
What could be awesome is a series of GPS locked SDR receivers at known
locations, on the RX frequency (with vertical antennas) - if you could pull
all the data together from the different RX's, this might be able to get a
good fix on the balloon.
Regards
Matty
MD0MAN
-----Original Message-----
From: amsat-bb-request@amsat.org
Sent: Thursday, February 16, 2012 8:00 PM
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Subject: AMSAT-BB Digest, Vol 7, Issue 79
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Today's Topics:
1. Dick Daniels (Martha)
2. Re: TransAtlantic Balloon on 28 MHz ? (Roger)
3. Re: TransAtlantic Balloon on 28 MHz ? (John Magliacane)
4. Re: TransAtlantic Balloon on 28 MHz ? (Bob Bruninga)
----------------------------------------------------------------------
Message: 1
Date: Thu, 16 Feb 2012 11:02:11 -0500
From: Martha martha@amsat.org
To: AMSAT BB amsat-bb@amsat.org, Board of Directors bod@amsat.org,
AMSAT Officers officers@amsat.org, Jan King
jking@eclipticenterprises.com
Cc: amsat-dc@amsat.org, Mark Kanawati mark@spacequest.com, Tak
Okamoto ja2pki@jamsat.or.jp
Subject: [amsat-bb] Dick Daniels
Message-ID:
CAPk0USwORY5LmbSsyuLfZJeY8Cm=3nK1mntNcut+4Wv-Zvoo_A@mail.gmail.com
Content-Type: text/plain; charset=ISO-8859-1
A memorial service will be held for Dick Daniels, W4PUJ on Saturday,
February 25th at 1:00PM . The location is the Little River Presbyterian
Church, 6025 Little Falls Rd, Arlington VA 22207. In lieu of flowers, the
family suggests a contribution to: Capital Caring, 950 N Glebe Rd #500,
Arlington VA 22203. This is the organization that provided hospice care for
Dick.
--
73- Martha
------------------------------
Message: 2
Date: Thu, 16 Feb 2012 11:39:48 -0500
From: Roger
Rogerkola@aol.com
To: amsat-bb@amsat.org
Subject: [amsat-bb] Re: TransAtlantic Balloon on 28 MHz ?
Message-ID:
4F3D3154.5030403@aol.com
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
CB uses vertical beams...the difficulty is that they have to have a non
metallic mounting pole extending into the beam or be end mounted (think
torque)
With enough planning I'm sure enough hams could chase something up and
use empty Stationmaster radomes, fiberglass poles or even schedule 80
pipe to get something up.
Roger
WA1KAT
On 2/16/2012 12:18 AM, Bob Bruninga wrote:
> Do you have a 10 meter (28 MHz) vertically polarized beam?
>
> We are working on a 28 MHz transatlantic Balloon with a CW transmitter on
> 10m using (of course) a vertical dipole.
>
> It will have no GPS, so tracking will be entirely by beam headings and
> some signal-strength assessment.
>
> Just wondering if anyone has a vertical beam.
>
> A horizontal beam will be useless for direction finding. All it will do
> is point to whatever is reflecting the energy into the strongest
> horizontal component...
>
> Hummh...
> Bob, WB4APR
> _______________________________________________
> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
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------------------------------
Message: 3
Date: Thu, 16 Feb 2012 11:37:43 -0800 (PST)
From: John Magliacane
kd2bd@yahoo.com
To: amsat-bb@amsat.org
Subject: [amsat-bb] Re: TransAtlantic Balloon on 28 MHz ?
Message-ID:
1329421063.8122.YahooMailClassic@web161402.mail.bf1.yahoo.com
Content-Type: text/plain; charset=us-ascii
--- On Thu, 2/16/12, Roger
Rogerkola@aol.com wrote:
> CB uses vertical beams...the difficulty is that they have to have
> a non metallic mounting pole extending into the beam or be end
> mounted (think torque)
The mounting pole may contribute some capacitive or inductive loading
effects on the elements adjacent to it, but a smart antenna designer can
modify the antenna's element lengths to compensate for these effects.
The pole itself will have a negligible effect on antenna performance, unless
it happens to be resonant (or very close to resonant) at the operating
frequency. Otherwise, it's essentially transparent.
> On 2/16/2012 12:18 AM, Bob Bruninga wrote:
>
> Just wondering if anyone has a vertical beam.
If the signal is strong enough (and/or the receiver sensitive enough), an
electrically small loop antenna can be used for 28 MHz radio direction
finding purposes.
A vertically oriented loop will respond to vertically polarized RF. (In
reality, it's responding to the horizontally polarized H-field).
The ARRL Handbooks and Antenna Books have carried designs regarding 28 MHz
RDF antenna for many decades.
73, de John, KD2BD
------------------------------
Message: 4
Date: Thu, 16 Feb 2012 14:51:06 -0500
From: "Bob Bruninga"
bruninga@usna.edu
To: "'Joe'"
nss@mwt.net,
amsat-bb@amsat.org
Subject: [amsat-bb] Re: TransAtlantic Balloon on 28 MHz ?
Message-ID:
050b01ccece4$52829550$f787bff0$@edu
Content-Type: text/plain; charset="us-ascii"
>> Just wondering if anyone has a vertical beam.
>> A horizontal beam [for this vertical balloon signal] will be
>> useless for direction finding....
> That is only true when receiving the signal
> via direct line of sight propagation.
The transmitter is only 10 milliwatts, so we only expect line-of-sight
contact. So that is why I was assuming we'd need a reasonable polarization
match. But who knows... maybe we will get some good OTH signals.? The
altitude will not be super high though, (like in the ionosphere)..
Bob, WB4APR
------------------------------
_______________________________________________
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
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End of AMSAT-BB Digest, Vol 7, Issue 79
***************************************
Matty Cunningham