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CX2SA > SATDIG 15.03.16 22:56l 1080 Lines 42210 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. Re: Ceuta & Melilla and Gibraltar this summer (David G0MRF)
2. Re: Ceuta & Melilla and Gibraltar this summer (David G0MRF)
3. Re: Homebrew Up-Dated Eggbeater Antenna (Joe)
4. Re: Homebrew Up-Dated Eggbeater Antenna (Robert Bruninga)
5. Re: Ceuta & Melilla and Gibraltar this summer (Dani EA4GPZ)
6. Re: Ceuta & Melilla and Gibraltar this summer (F?lix P?ez)
7. Re: Homebrew Up-Dated Eggbeater Antenna (Robert Bruninga)
8. Re: Homebrew Up-Dated Eggbeater Antenna (correction)
(Robert Bruninga)
9. Re: Homebrew Up-Dated Eggbeater Antenna (correction)
(Bill Attwood)
10. Re: Homebrew Up-Dated Eggbeater Antenna (correction) (Joe)
----------------------------------------------------------------------
Message: 1
Date: Tue, 15 Mar 2016 13:16:37 -0400
From: David G0MRF <g0mrf@xxx.xxx>
To: ea4gqs@xxxxx.xxxx amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Message-ID: <1537b4781f1-6b66-df6b@xxxxxxxxxx.xxxx.xxx.xxx>
Content-Type: text/plain; charset=utf-8
Hi Felix
Make sure you apply for your ZB licence in plenty of time. I went there
several years ago and found they are not part of the CEPT agreement.
Good luck. ZB2 is on my 'wanted list'
David
-----Original Message-----
From: Felix Paez EA4GQS <ea4gqs@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Sent: Mon, 14 Mar 2016 9:57
Subject: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Hi everybody,I want to share with you all that this August I will try to
activateGibraltar (ZB) the EA9 zone from Ceuta on portable on any avaliable
FMsatellite in the time I will be there. Also I will try to activate all
theno frequent grids from Madrid to the South of Spain in my way.I don't
know how many passes and which satellites I will be able to useuntil I know
the exact date of the trip but I will try to plan it so I canwork at least
one pass from Gibraltar and another one from Ceuta.I will share the details
on June or July in this list. All QSOs will beconfirmed by LOTW.I am really
sorry that I don't have at the moment any SSB portabletransceiver. I know it
would be great for our not European friends. We willsee if something can be
done about it these months..ThanksF?lix -
EA4GQS_______________________________________________Sent via
AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum availableto all
interested persons worldwide without requiring membership. Opinions
expressedare 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: 2
Date: Tue, 15 Mar 2016 13:16:44 -0400
From: David G0MRF <g0mrf@xxx.xxx>
To: ea4gqs@xxxxx.xxxx amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Message-ID: <1537b479ce9-6b66-df6d@xxxxxxxxxx.xxxx.xxx.xxx>
Content-Type: text/plain; charset=utf-8
Hi Felix
Make sure you apply for your ZB licence in plenty of time. I went there
several years ago and found they are not part of the CEPT agreement.
Good luck. ZB2 is on my 'wanted list'
David
-----Original Message-----
From: Felix Paez EA4GQS <ea4gqs@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Sent: Mon, 14 Mar 2016 9:57
Subject: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Hi everybody,I want to share with you all that this August I will try to
activateGibraltar (ZB) the EA9 zone from Ceuta on portable on any avaliable
FMsatellite in the time I will be there. Also I will try to activate all
theno frequent grids from Madrid to the South of Spain in my way.I don't
know how many passes and which satellites I will be able to useuntil I know
the exact date of the trip but I will try to plan it so I canwork at least
one pass from Gibraltar and another one from Ceuta.I will share the details
on June or July in this list. All QSOs will beconfirmed by LOTW.I am really
sorry that I don't have at the moment any SSB portabletransceiver. I know it
would be great for our not European friends. We willsee if something can be
done about it these months..ThanksF?lix -
EA4GQS_______________________________________________Sent via
AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum availableto all
interested persons worldwide without requiring membership. Opinions
expressedare 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: 3
Date: Tue, 15 Mar 2016 12:27:04 -0500
From: Joe <nss@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
Message-ID: <56E845E8.9020708@xxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
Bummer!
I'm looking for some sort of an Omni ant to use with NO-84
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 3/15/2016 11:46 AM, Jim Walls wrote:
> I built one about a decade or so ago and was grossly underwhelmed with it.
> I built it to use for a sat igate. I was able to decode maybe one or two
> packets per day. Everything else was lost in the noise floor.. Only had
> about 20 feet of RG-214 cable to the receiver.
>
> Jim - K6CCC
>
>
>
>
>
> ----------------------------------------
> From: "Joe" <nss@xxx.xxx>
> Sent: Tuesday, March 15, 2016 9:37 AM
> To: "amsat-bb@xxxxx org" <amsat-bb@xxxxx.xxx>
> Subject: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
> Has anyone built this antenna, and what are your opinions? Meet all the
> claims being made?
>
> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>
> Joe WB9SBD
> --
> Sig
> The Original Rolling Ball Clock
> Idle Tyme
> Idle-Tyme.com
> http://www.idle-tyme.com
> _______________________________________________
> 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: 4
Date: Tue, 15 Mar 2016 13:32:22 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
Message-ID: <cd86d0229cc44db072972ca69808e7d9@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
My 2 cents:
The problem with Eggbeaters is that their design goal (omni coverage)
sounds good but also means, by definition, equally poor in all directions.
There is no such thing as "gain" for an omni. The closer its gain
approaches 3D omni, in all directions, then the closer its gain approaches
0 dBi. Of course, placed over a ground plane, then they can achieve 3
dBi...
Now, on the other hand, satellites are nowhere near omni located. They
are 10dB or more farther away on the horizon than when they are overhead.
So you don't need as much gain at all overhead as you need on the horizon.
Further, satellites spend more than 70% of all pass times below 22
degrees! (where they are weak) and only 5% of their time above 45 degrees
where they are 10 dB stronger.
The last thing then that you need for "omni" coverage for a non-pointing
antenna, then, is gain that is UP (where the satellite is 10 times
stronger).
See the scale drawings of a LEO pass: http://aprs.org/LEO-tracking.html
BUT on the other hand, most cubesats simply do not have the power to close
the link to an OMNI antenna when it is on the horizon. It just cannot
happen due to the distance and the omni only being at best 3 dB gain.
So the BEST "omni" in my opinion is a 19" whip over a large metal ground
plane. Not only does it provide 5 dBi gain above 15 degrees or so on VHF,
it also provides almost 7 dBi gain on UHF above about 30 degrees where it
acts as a 3/4 wave vertical..
Yes, it has a null overhead, but the satellite is 10 times stronger then.
And the satleilte is only in that null less than 2% of all pass times.
So the 19" vertical gives good gain from above the horizon in all
directions and sacrificaes some gain overhead wehre it is not needed. And
no omni antenna is going to hear these weak satellites all the way down
on the horizon where they are 10 times weaker.
And a 19.25" vertical piece of wire over some chicken wire is pretty easy
to construct, AND it does not need to be on the top of a tower, since it
cannot hear to the horizon anyway. So jjust put it where it can see most
of the sky above abouit 15 degrees and you will hear about all you can on
an Omni. And it is not bad...
The value of a true circular hemispherical antenna is only when the
satelile is strong (ISS) and it can be heard even on the horizon. Then
the circula hemispherical antenna has the advantage of fewer nulls in its
pattern. But you give up gain where it is most needed to get that.
And a low noise preamp is essential...
Just my 2 cents...
Bob, WB4APR
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Paul
Stoetzer
Sent: Tuesday, March 15, 2016 1:12 PM
To: jim@xxxxx.xxx
Cc: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
Jim,
The key words here are "noise floor." Omnidirectional antennas can work
for satellites when you have a low noise floor and short runs of very good
coax (and/or a preamp).
As an example, I've listened for SO-50 a couple of times from here in
Washington, DC with my Baofeng UV-3R+ and Nagoya NA-774 telescopic whip. I
can hear the satellite a bit, but still quite nosily, above 45 degrees.
Back in August, I was in a field in the middle of nowhere and heard it
very well from 5-7 degrees above the horizon.
Another example is that some people report decent telemetry success from
AO-73 (when in high power mode) using nothing more than 1/4 wave whip.
I've never been able to decode a single packet with that type of setup
here in the city.
Most people live somewhere between the two extremes I've presented here of
"field in the middle of nowhere" and "apartment building in a major urban
center" so your mileage may vary. Just keep in mind that in any receiving
system, you are looking for an optimal signal to noise ratio. If you have
no noise, you don't need much signal and omnidirectional antennas might
work fine. If you have a ton of noise, you are going to need a lot of
signal from the satellite, which means a beam with decent gain.
73,
Paul, N8HM
On Tue, Mar 15, 2016 at 12:46 PM, Jim Walls <jim@xxxxx.xxx> wrote:
> I built one about a decade or so ago and was grossly underwhelmed with
it.
> I built it to use for a sat igate. I was able to decode maybe one or
> two packets per day. Everything else was lost in the noise floor..
> Only had about 20 feet of RG-214 cable to the receiver.
>
> Jim - K6CCC
>
>
>
>
>
> ----------------------------------------
> From: "Joe" <nss@xxx.xxx>
> Sent: Tuesday, March 15, 2016 9:37 AM
> To: "amsat-bb@xxxxx org" <amsat-bb@xxxxx.xxx>
> Subject: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna Has anyone
> built this antenna, and what are your opinions? Meet all the claims
> being made?
>
> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>
> Joe WB9SBD
> --
> Sig
> The Original Rolling Ball Clock
> Idle Tyme
> Idle-Tyme.com
> http://www.idle-tyme.com
> _______________________________________________
> 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
_______________________________________________
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: Tue, 15 Mar 2016 18:34:13 +0100
From: Dani EA4GPZ <daniel@xxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Message-ID: <56E84795.7080609@xxxxxxxx.xxx>
Content-Type: text/plain; charset=utf-8
El 15/03/16 a las 18:16, David G0MRF via AMSAT-BB escribi?:
> Hi Felix
>
> Make sure you apply for your ZB licence in plenty of time. I went there
several years ago and found they are not part of the CEPT agreement.
>
> Good luck. ZB2 is on my 'wanted list'
Hi David,
That's good to know. I'm not the original poster (and I'm in fact
looking forward to his future trip), but I had the wrong impression that
either a UK licence or a CEPT licence could be used in ZB (actually none
of those are valid there).
More info:
http://www.gra.gi/communications/amateur-radio-reciprocal-licence
Also note that operation is restricted to the 6m, 4m, 2m and 70cm bands
and the maximum power is 100W ERP. So watch out for the maximum power on
70cm, as it is easy to surpass it if you use a high gain antenna.
For instance, on a 7 element yagi (say 9.82dBd gain), the maximum output
power you can use is about 10W.
73,
Dani EA4GPZ.
------------------------------
Message: 6
Date: Tue, 15 Mar 2016 19:28:26 +0100
From: F?lix P?ez <ea4gqs@xxxxx.xxx>
To: David G0MRF <g0mrf@xxx.xxx>, "amsat-bb@xxxxx.xxxx
<amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Message-ID: <56e85434.465ec20a.25769.792e@xx.xxxxxx.xxx>
Content-Type: text/plain; charset="utf-8"
Hi David,
Thanks for the advice? I have just send them an email to be sure If I need
an authorization?
I need to know too If I need something for Ceuta, but I don?t think so?
Felix
Enviado desde Correo para Windows 10
De: David G0MRF
Enviado: martes, 15 de marzo de 2016 18:16
Para: ea4gqs@xxxxx.xxxx amsat-bb@xxxxx.xxx
Asunto: Re: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Hi Felix
Make sure you apply for your ZB licence in plenty of time.?? I went there
several years ago and found they are not part of the CEPT agreement.
Good luck.?? ZB2 is on my 'wanted list'
David
-----Original Message-----
From: Felix Paez EA4GQS <ea4gqs@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Sent: Mon, 14 Mar 2016 9:57
Subject: [amsat-bb] Ceuta & Melilla and Gibraltar this summer
Hi everybody, I want to share with you all that this August I will try to
activate Gibraltar (ZB) the EA9 zone from Ceuta on portable on any avaliable
FM satellite in the time I will be there. Also I will try to activate all
the no frequent grids from Madrid to the South of Spain in my way. I don't
know how many passes and which satellites I will be able to use until I know
the exact date of the trip but I will try to plan it so I can work at least
one pass from Gibraltar and another one from Ceuta. I will share the details
on June or July in this list. All QSOs will be confirmed by LOTW. I am
really sorry that I don't have at the moment any SSB portable transceiver. I
know it would be great for our not European friends. We will see if
something can be done about it these months.. Thanks F?lix - EA4GQS
_______________________________________________ Sent via AMSAT-BB@xxxxx.xxx.
AMSAT-NA makes this open forum available to all interested persons worldwide
without requiring memb
ership. 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: Tue, 15 Mar 2016 14:50:03 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
Message-ID: <be555faf3e02353a9504a15c7d4d2bc3@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
NO84 is only 300 mW compared to 2W for the original PCSAT and 5W for the
ISS (currently). You need gain to hear it...
If you want a non-moving fixed antenna to hear NO84, I'd try a 58"
vertical whip over a large metal ground plane. This would give you up to
7 dBi above about 30 degrees. Then you would hear it every day, but only
for the better passes above 25 degrees. But you would hear it then.
And I modeled it in EZNEC and just a vertical over say 4 radials is not
the same thing. That helps matching, but does not block the 3db part of
the pattern into the ground. You need a real "ground plane" of a metal
roof, or about 6 feet or more of chicken wire.
Easy for me to say, because I have not built one yet...
Bob, WB4APR
-----Original Message-----
> Bummer! I'm looking for some sort of an Omni ant to use with NO-84
------------------------------
Message: 8
Date: Tue, 15 Mar 2016 16:11:08 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
(correction)
Message-ID: <b9e1a609be75364ca22fe480fca55635@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Although my comments are true, I had not looked at the "updated" web page:
http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
It appears he addressed all those issues and has an eggbeater design that
does address those same issues. If that works, then that is the same thing
I was talking about and seems to be a good approach. I'd love to see a
cookoff between the two antennas. Bob...
-----Original Message-----
From: Robert Bruninga [mailto:bruninga@xxxx.xxxx
Sent: Tuesday, March 15, 2016 1:32 PM
Subject: RE: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
My 2 cents:
The problem with Eggbeaters is that their design goal (omni coverage) sounds
good but also means, by definition, equally poor in all directions.
There is no such thing as "gain" for an omni. The closer its gain
approaches 3D omni, in all directions, then the closer its gain approaches
0 dBi. Of course, placed over a ground plane, then they can achieve 3
dBi...
Now, on the other hand, satellites are nowhere near omni located. They are
10dB or more farther away on the horizon than when they are overhead.
So you don't need as much gain at all overhead as you need on the horizon.
Further, satellites spend more than 70% of all pass times below 22 degrees!
(where they are weak) and only 5% of their time above 45 degrees where they
are 10 dB stronger.
The last thing then that you need for "omni" coverage for a non-pointing
antenna, then, is gain that is UP (where the satellite is 10 times
stronger).
See the scale drawings of a LEO pass: http://aprs.org/LEO-tracking.html
BUT on the other hand, most cubesats simply do not have the power to close
the link to an OMNI antenna when it is on the horizon. It just cannot
happen due to the distance and the omni only being at best 3 dB gain.
So the BEST "omni" in my opinion is a 19" whip over a large metal ground
plane. Not only does it provide 5 dBi gain above 15 degrees or so on VHF,
it also provides almost 7 dBi gain on UHF above about 30 degrees where it
acts as a 3/4 wave vertical..
Yes, it has a null overhead, but the satellite is 10 times stronger then.
And the satleilte is only in that null less than 2% of all pass times.
So the 19" vertical gives good gain from above the horizon in all directions
and sacrificaes some gain overhead wehre it is not needed. And no omni
antenna is going to hear these weak satellites all the way down on the
horizon where they are 10 times weaker.
And a 19.25" vertical piece of wire over some chicken wire is pretty easy to
construct, AND it does not need to be on the top of a tower, since it cannot
hear to the horizon anyway. So jjust put it where it can see most of the
sky above abouit 15 degrees and you will hear about all you can on an Omni.
And it is not bad...
The value of a true circular hemispherical antenna is only when the satelile
is strong (ISS) and it can be heard even on the horizon. Then the circula
hemispherical antenna has the advantage of fewer nulls in its pattern. But
you give up gain where it is most needed to get that.
And a low noise preamp is essential...
Just my 2 cents...
Bob, WB4APR
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Paul
Stoetzer
Sent: Tuesday, March 15, 2016 1:12 PM
To: jim@xxxxx.xxx
Cc: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
Jim,
The key words here are "noise floor." Omnidirectional antennas can work for
satellites when you have a low noise floor and short runs of very good coax
(and/or a preamp).
As an example, I've listened for SO-50 a couple of times from here in
Washington, DC with my Baofeng UV-3R+ and Nagoya NA-774 telescopic whip. I
can hear the satellite a bit, but still quite nosily, above 45 degrees.
Back in August, I was in a field in the middle of nowhere and heard it very
well from 5-7 degrees above the horizon.
Another example is that some people report decent telemetry success from
AO-73 (when in high power mode) using nothing more than 1/4 wave whip.
I've never been able to decode a single packet with that type of setup here
in the city.
Most people live somewhere between the two extremes I've presented here of
"field in the middle of nowhere" and "apartment building in a major urban
center" so your mileage may vary. Just keep in mind that in any receiving
system, you are looking for an optimal signal to noise ratio. If you have no
noise, you don't need much signal and omnidirectional antennas might work
fine. If you have a ton of noise, you are going to need a lot of signal from
the satellite, which means a beam with decent gain.
73,
Paul, N8HM
On Tue, Mar 15, 2016 at 12:46 PM, Jim Walls <jim@xxxxx.xxx> wrote:
> I built one about a decade or so ago and was grossly underwhelmed with
it.
> I built it to use for a sat igate. I was able to decode maybe one or
> two packets per day. Everything else was lost in the noise floor..
> Only had about 20 feet of RG-214 cable to the receiver.
>
> Jim - K6CCC
>
>
>
>
>
> ----------------------------------------
> From: "Joe" <nss@xxx.xxx>
> Sent: Tuesday, March 15, 2016 9:37 AM
> To: "amsat-bb@xxxxx org" <amsat-bb@xxxxx.xxx>
> Subject: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna Has anyone
> built this antenna, and what are your opinions? Meet all the claims
> being made?
>
> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>
> Joe WB9SBD
> --
> Sig
> The Original Rolling Ball Clock
> Idle Tyme
> Idle-Tyme.com
> http://www.idle-tyme.com
> _______________________________________________
> 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
_______________________________________________
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: 9
Date: Tue, 15 Mar 2016 14:34:40 -0600
From: Bill Attwood <whattwood@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
(correction)
Message-ID: <56E871E0.3020400@xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
Bob, I understand you feel strongly (for good reason) about using a
vertical for satellite purposes. However, do some of these other antenna
designs do a better job of dealing with polarity mismatch than a
vertical would? I ask because I simply don't know.
Thanks,
Bill
VE6WK
On 2016-03-15 2:11 PM, Robert Bruninga wrote:
> Although my comments are true, I had not looked at the "updated" web page:
> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>
> It appears he addressed all those issues and has an eggbeater design that
> does address those same issues. If that works, then that is the same thing
> I was talking about and seems to be a good approach. I'd love to see a
> cookoff between the two antennas. Bob...
>
> -----Original Message-----
> From: Robert Bruninga [mailto:bruninga@xxxx.xxxx
> Sent: Tuesday, March 15, 2016 1:32 PM
> Subject: RE: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
>
> My 2 cents:
>
> The problem with Eggbeaters is that their design goal (omni coverage) sounds
> good but also means, by definition, equally poor in all directions.
> There is no such thing as "gain" for an omni. The closer its gain
> approaches 3D omni, in all directions, then the closer its gain approaches
> 0 dBi. Of course, placed over a ground plane, then they can achieve 3
> dBi...
>
> Now, on the other hand, satellites are nowhere near omni located. They are
> 10dB or more farther away on the horizon than when they are overhead.
> So you don't need as much gain at all overhead as you need on the horizon.
>
> Further, satellites spend more than 70% of all pass times below 22 degrees!
> (where they are weak) and only 5% of their time above 45 degrees where they
> are 10 dB stronger.
>
> The last thing then that you need for "omni" coverage for a non-pointing
> antenna, then, is gain that is UP (where the satellite is 10 times
> stronger).
>
> See the scale drawings of a LEO pass: http://aprs.org/LEO-tracking.html
>
> BUT on the other hand, most cubesats simply do not have the power to close
> the link to an OMNI antenna when it is on the horizon. It just cannot
> happen due to the distance and the omni only being at best 3 dB gain.
>
> So the BEST "omni" in my opinion is a 19" whip over a large metal ground
> plane. Not only does it provide 5 dBi gain above 15 degrees or so on VHF,
> it also provides almost 7 dBi gain on UHF above about 30 degrees where it
> acts as a 3/4 wave vertical..
>
> Yes, it has a null overhead, but the satellite is 10 times stronger then.
> And the satleilte is only in that null less than 2% of all pass times.
>
> So the 19" vertical gives good gain from above the horizon in all directions
> and sacrificaes some gain overhead wehre it is not needed. And no omni
> antenna is going to hear these weak satellites all the way down on the
> horizon where they are 10 times weaker.
>
> And a 19.25" vertical piece of wire over some chicken wire is pretty easy to
> construct, AND it does not need to be on the top of a tower, since it cannot
> hear to the horizon anyway. So jjust put it where it can see most of the
> sky above abouit 15 degrees and you will hear about all you can on an Omni.
> And it is not bad...
>
> The value of a true circular hemispherical antenna is only when the satelile
> is strong (ISS) and it can be heard even on the horizon. Then the circula
> hemispherical antenna has the advantage of fewer nulls in its pattern. But
> you give up gain where it is most needed to get that.
>
> And a low noise preamp is essential...
>
> Just my 2 cents...
> Bob, WB4APR
>
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Paul
> Stoetzer
> Sent: Tuesday, March 15, 2016 1:12 PM
> To: jim@xxxxx.xxx
> Cc: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
>
> Jim,
>
> The key words here are "noise floor." Omnidirectional antennas can work for
> satellites when you have a low noise floor and short runs of very good coax
> (and/or a preamp).
>
> As an example, I've listened for SO-50 a couple of times from here in
> Washington, DC with my Baofeng UV-3R+ and Nagoya NA-774 telescopic whip. I
> can hear the satellite a bit, but still quite nosily, above 45 degrees.
> Back in August, I was in a field in the middle of nowhere and heard it very
> well from 5-7 degrees above the horizon.
>
> Another example is that some people report decent telemetry success from
> AO-73 (when in high power mode) using nothing more than 1/4 wave whip.
> I've never been able to decode a single packet with that type of setup here
> in the city.
>
> Most people live somewhere between the two extremes I've presented here of
> "field in the middle of nowhere" and "apartment building in a major urban
> center" so your mileage may vary. Just keep in mind that in any receiving
> system, you are looking for an optimal signal to noise ratio. If you have no
> noise, you don't need much signal and omnidirectional antennas might work
> fine. If you have a ton of noise, you are going to need a lot of signal from
> the satellite, which means a beam with decent gain.
>
> 73,
>
> Paul, N8HM
>
> On Tue, Mar 15, 2016 at 12:46 PM, Jim Walls <jim@xxxxx.xxx> wrote:
>> I built one about a decade or so ago and was grossly underwhelmed with
> it.
>> I built it to use for a sat igate. I was able to decode maybe one or
>> two packets per day. Everything else was lost in the noise floor..
>> Only had about 20 feet of RG-214 cable to the receiver.
>>
>> Jim - K6CCC
>>
>>
>>
>>
>>
>> ----------------------------------------
>> From: "Joe" <nss@xxx.xxx>
>> Sent: Tuesday, March 15, 2016 9:37 AM
>> To: "amsat-bb@xxxxx org" <amsat-bb@xxxxx.xxx>
>> Subject: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna Has anyone
>> built this antenna, and what are your opinions? Meet all the claims
>> being made?
>>
>> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>>
>> Joe WB9SBD
>> --
>> Sig
>> The Original Rolling Ball Clock
>> Idle Tyme
>> Idle-Tyme.com
>> http://www.idle-tyme.com
>> _______________________________________________
>> 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
> _______________________________________________
> 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!
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Message: 10
Date: Tue, 15 Mar 2016 15:45:14 -0500
From: Joe <nss@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
(correction)
Message-ID: <56E8745A.20205@xxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
Main problem seems to be the 93 ohm coax,,,
anyone got a short piece?
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 3/15/2016 3:11 PM, Robert Bruninga wrote:
> Although my comments are true, I had not looked at the "updated" web page:
> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>
> It appears he addressed all those issues and has an eggbeater design that
> does address those same issues. If that works, then that is the same thing
> I was talking about and seems to be a good approach. I'd love to see a
> cookoff between the two antennas. Bob...
>
> -----Original Message-----
> From: Robert Bruninga [mailto:bruninga@xxxx.xxxx
> Sent: Tuesday, March 15, 2016 1:32 PM
> Subject: RE: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
>
> My 2 cents:
>
> The problem with Eggbeaters is that their design goal (omni coverage) sounds
> good but also means, by definition, equally poor in all directions.
> There is no such thing as "gain" for an omni. The closer its gain
> approaches 3D omni, in all directions, then the closer its gain approaches
> 0 dBi. Of course, placed over a ground plane, then they can achieve 3
> dBi...
>
> Now, on the other hand, satellites are nowhere near omni located. They are
> 10dB or more farther away on the horizon than when they are overhead.
> So you don't need as much gain at all overhead as you need on the horizon.
>
> Further, satellites spend more than 70% of all pass times below 22 degrees!
> (where they are weak) and only 5% of their time above 45 degrees where they
> are 10 dB stronger.
>
> The last thing then that you need for "omni" coverage for a non-pointing
> antenna, then, is gain that is UP (where the satellite is 10 times
> stronger).
>
> See the scale drawings of a LEO pass: http://aprs.org/LEO-tracking.html
>
> BUT on the other hand, most cubesats simply do not have the power to close
> the link to an OMNI antenna when it is on the horizon. It just cannot
> happen due to the distance and the omni only being at best 3 dB gain.
>
> So the BEST "omni" in my opinion is a 19" whip over a large metal ground
> plane. Not only does it provide 5 dBi gain above 15 degrees or so on VHF,
> it also provides almost 7 dBi gain on UHF above about 30 degrees where it
> acts as a 3/4 wave vertical..
>
> Yes, it has a null overhead, but the satellite is 10 times stronger then.
> And the satleilte is only in that null less than 2% of all pass times.
>
> So the 19" vertical gives good gain from above the horizon in all directions
> and sacrificaes some gain overhead wehre it is not needed. And no omni
> antenna is going to hear these weak satellites all the way down on the
> horizon where they are 10 times weaker.
>
> And a 19.25" vertical piece of wire over some chicken wire is pretty easy to
> construct, AND it does not need to be on the top of a tower, since it cannot
> hear to the horizon anyway. So jjust put it where it can see most of the
> sky above abouit 15 degrees and you will hear about all you can on an Omni.
> And it is not bad...
>
> The value of a true circular hemispherical antenna is only when the satelile
> is strong (ISS) and it can be heard even on the horizon. Then the circula
> hemispherical antenna has the advantage of fewer nulls in its pattern. But
> you give up gain where it is most needed to get that.
>
> And a low noise preamp is essential...
>
> Just my 2 cents...
> Bob, WB4APR
>
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Paul
> Stoetzer
> Sent: Tuesday, March 15, 2016 1:12 PM
> To: jim@xxxxx.xxx
> Cc: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna
>
> Jim,
>
> The key words here are "noise floor." Omnidirectional antennas can work for
> satellites when you have a low noise floor and short runs of very good coax
> (and/or a preamp).
>
> As an example, I've listened for SO-50 a couple of times from here in
> Washington, DC with my Baofeng UV-3R+ and Nagoya NA-774 telescopic whip. I
> can hear the satellite a bit, but still quite nosily, above 45 degrees.
> Back in August, I was in a field in the middle of nowhere and heard it very
> well from 5-7 degrees above the horizon.
>
> Another example is that some people report decent telemetry success from
> AO-73 (when in high power mode) using nothing more than 1/4 wave whip.
> I've never been able to decode a single packet with that type of setup here
> in the city.
>
> Most people live somewhere between the two extremes I've presented here of
> "field in the middle of nowhere" and "apartment building in a major urban
> center" so your mileage may vary. Just keep in mind that in any receiving
> system, you are looking for an optimal signal to noise ratio. If you have no
> noise, you don't need much signal and omnidirectional antennas might work
> fine. If you have a ton of noise, you are going to need a lot of signal from
> the satellite, which means a beam with decent gain.
>
> 73,
>
> Paul, N8HM
>
> On Tue, Mar 15, 2016 at 12:46 PM, Jim Walls <jim@xxxxx.xxx> wrote:
>> I built one about a decade or so ago and was grossly underwhelmed with
> it.
>> I built it to use for a sat igate. I was able to decode maybe one or
>> two packets per day. Everything else was lost in the noise floor..
>> Only had about 20 feet of RG-214 cable to the receiver.
>>
>> Jim - K6CCC
>>
>>
>>
>>
>>
>> ----------------------------------------
>> From: "Joe" <nss@xxx.xxx>
>> Sent: Tuesday, March 15, 2016 9:37 AM
>> To: "amsat-bb@xxxxx org" <amsat-bb@xxxxx.xxx>
>> Subject: [amsat-bb] Homebrew Up-Dated Eggbeater Antenna Has anyone
>> built this antenna, and what are your opinions? Meet all the claims
>> being made?
>>
>> http://wb5rmg.somenet.net/k5oe/Eggbeater_2.html
>>
>> Joe WB9SBD
>> --
>> Sig
>> The Original Rolling Ball Clock
>> Idle Tyme
>> Idle-Tyme.com
>> http://www.idle-tyme.com
>> _______________________________________________
>> 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
> _______________________________________________
> 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
>
>
>
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