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CX2SA > SATDIG 10.04.13 21:05l 596 Lines 20695 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. FUNcube Project - Your advice requested (Graham Shirville)
2. 2M1EUB/P OPPS UPDATE WEDNESDAY IO97CM (paul robinson)
3. OFFICE CLOSED (Martha)
4. Re: FUNcube Project - 7 dBi omni (Robert Bruninga)
5. Re: FUNcube Project - Your advice requested (Gary Mayfield)
6. Re: OFFICE CLOSED (George Henry)
7. AO7 Mode Switch (K4FEG)
8. Re: AO7 Mode Switch (PE0SAT | Amateur Radio)
9. UPDATE 2M1EUB/P OPPS IO97CM WORKED (paul robinson)
10. ao7 mode switch k4feg-2m1eub/p (paul robinson)
----------------------------------------------------------------------
Message: 1
Date: Tue, 9 Apr 2013 20:46:59 +0100
From: "Graham Shirville" <g.shirville@xxxxxxxxxx.xxx>
To: "AMSAT BB" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] FUNcube Project - Your advice requested
Message-ID: <43ACC33838004CB197E0A1802A06DFAD@xxxxxxx.xxxxx>
Content-Type: text/plain; format=flowed; charset="UTF-8";
reply-type=original
Hi All,
As part of the FUNcube project we now need to urgently decide which is going
to be the best type of antenna to propose for use at schools and colleges to
receive the 145MHz downlink signals from both FUNcube-1 and FUNcube-2 on
UKube after launch.
Both spacecraft will be transmitting approx 300mW of BPSK 1k2 telemetry with
FEC ? FC1- will be using a dipole antenna and will have passive magnetic
attitude control. FC-2 on UKube will use a single monopole antenna and the
spacecraft is intended to have active attitude control. This is primarily to
ensure that the deployed solar panels are illuminated and that the face with
the S band patch is usually earth pointing.
We believe that the resultant signal should be easily usable using an
omnidirectional antenna but the questions is which would be the best type to
use. Obviously ease of construction, cost, robustness and safety in a school
environment will also be important factors as well as suitable ?gain? and
circularity from horizon to horizon. We envisage that some operations may be
from fixed installations with the antennas mounted permanently but some will
be temporary - perhaps hand held or bolted to a step ladder or similar.
We know there are many AMSAT members around the globe with great experience
in this field and, we suspect, with some strongly held views. So please let
us have some constructive input about which type is likely to be best for
this purpose - your comments, ideas and lessons learnt will be very valuable
for us.
Thanks in advance for your support
73
Graham
G3VZV - for the FUNcube Project team
As part of the FUNcube project we need to decide which is going to be the
best antenna to propose for use at schools and colleges to receives the
145MHz downlink signals from both FUNcube-1 and FUNcube-2 on UKube after
launch.
Both spacecraft will be transmitting approx 300mW of BPSK 1k2 telemetry with
FEC ? FC1- will be using a dipole antenna and has passive magnetic attitude
control. FC-2 on UKube will use a single monopole antenna and the spacecraft
is intended to have active attitude control to ensure that the deployed
solar panels are illuminated and that the face with the S band patch is
usually earth pointing.
We believe that the resultant signal should be easily usable using an
omnidirectional antenna but the questions is which would be the best type to
use. Obviously ease of construction, cost, robustness and safety in a school
environment will also be important factors as well as suitable ?gain? and
circularity from horizon to horizon.
We know there are many AMSAT members with experience in this field and, we
suspect, some strongly held views but all constructive input would be very
welcome.
------------------------------
Message: 2
Date: Tue, 9 Apr 2013 20:54:38 +0100 (BST)
From: paul robinson <pushbiker2004@xxxxx.xx.xx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] 2M1EUB/P OPPS UPDATE WEDNESDAY IO97CM
Message-ID:
<1365537278.69091.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Tomorrow wednesday,ill be driving to Peterhead Aberdeenshire,on the N.E
coast corner of Scotland, grid sq IO97CM which is a rare grid to be
had....fo29 and ao7 ,please make the qso as quick as poss as there may be
lots of interested stations looking for me and time is short...ill only be
there for a few hours in day light ,mid day passes,GMT.after that ill be
back to io87nc till saturday.Hope this works out for every one who is
interested ill be around 145.950 a07 and 435.850 fo29,if for any reason ao7
is in mode A ill be around 29.450mhz ...de paul 2M1EUB/P.... QSL? dirrect
via 2E1EUB
------------------------------
Message: 3
Date: Tue, 9 Apr 2013 17:02:04 -0400
From: Martha <martha@xxxxx.xxx>
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] OFFICE CLOSED
Message-ID:
<CAPk0USxhxsQNaysf_eRCno-6nJUAhN9zCSzc5uf_TBgEXjQX1w@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
The AMSAT office will be closed from Wednesday, April 10th to Monday April
15th. I am taking a birthday holiday to Florida
--
73- Martha
------------------------------
Message: 4
Date: Tue, 9 Apr 2013 17:08:05 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: Graham Shirville <g.shirville@xxxxxxxxxx.xxx>, AMSAT BB
<amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: FUNcube Project - 7 dBi omni
Message-ID: <600affe19f8f76254c9fcf16fc6aa04d@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
> ... which is going to be the best type of antenna...
> to receive the 145MHz downlink signals
There are lots of good hemispherical satellite antennas that provide equal
gain for all satellites in view. However, these designs ignore the fact
that satellites on the horizon (LEO passes spend almost 70% of their time
below say 22 degrees) are so far away, most of them are too weak to be
decoded until they get closer (and higher) anyway. Given the weak downlink
(300mw) of FunCube there is no -omni- antenna that is going to decode that
signal at the horizon when the satellite is over 1500km away.
In this light, it is better to simply sacrifice low angle coverage and
concentrate the gain higher up to make sure that when the satellite does get
to high angles, then there is plenty of gain to decode it.
The simplest and best performance (for LEO satellites) and easiest to
construct is a 3/4 wave vertical over a ground plane. It has over 7 dBi
gain above 25 or 30 degrees and requires no matching circuit. Just shield
to ground plane and center coax to the 3/4 wave whip.
The antenna pattern is ideal for LEO satellites because it concentrates the
gain above 30 degrees and does not waste gain down on the horizon where
satellites are 6 to 10 dB farther away and not decodable on an omni anyway
unless the satellite has decent power (which the fun cube does not).
Background: In the past, a 19" whip is an ideal 3/4 wave gain vertical for
UHF (over 7 dBi) and also acts as a 1/4 wave vertical (5 dBi) for VHF. A
nice dual band antenna for satellite work with weak UHF downlinks. But then
Funcube is not UHF, but VHF. So you want more gain on the VHF downlink, so
you would want to make this antenna almost 58 inches long to be 3/4 wave on
VHF (and ignore it for UHF where the gain pattern would be too narrow).
Also, by having reduced gain on the horizon, the VHF link will have less
noise to contend with.
You don?t you see this excellent antenna more often because it is useless
for terrestrial operation (negative gain on the horizon), and for
satellites, most people think they want omni-gain on the horizon even
though for anything other than the 10W transmitter on the ISS, they still
won't decode anything on the horizon until the satellite gets higher (and
closer) anyway.
So my receommendation is the 3/4 wave vertical for unattended fixed omni
operation with high gain above say about 25 degrees and use a gain YAGI and
tracking antenna if you need to have coverage down to the horizon.
The over 7 dBi gain of this simple 3/4 wave antenna plus the nearly 5 dB
path-loss (and noise) gain of VHF over UHF for omni antennas makes this link
over 12 dB better than a comparable UHF downlink to-an-omni experience with
cubesats.
My opinion anyway. You can see some of my early writings on this antenna
about 80% down this page: http://aprs.org/astars.html
Bob, Wb4APR
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Graham Shirville
Sent: Tuesday, April 09, 2013 3:47 PM
To: AMSAT BB
Subject: [amsat-bb] FUNcube Project - Your advice requested
Hi All,
As part of the FUNcube project we now need to urgently decide which is going
to be the best type of antenna to propose for use at schools and colleges to
receive the 145MHz downlink signals from both FUNcube-1 and FUNcube-2 on
UKube after launch.
Both spacecraft will be transmitting approx 300mW of BPSK 1k2 telemetry with
FEC ? FC1- will be using a dipole antenna and will have passive magnetic
attitude control. FC-2 on UKube will use a single monopole antenna and the
spacecraft is intended to have active attitude control. This is primarily to
ensure that the deployed solar panels are illuminated and that the face with
the S band patch is usually earth pointing.
We believe that the resultant signal should be easily usable using an
omnidirectional antenna but the questions is which would be the best type to
use. Obviously ease of construction, cost, robustness and safety in a school
environment will also be important factors as well as suitable ?gain? and
circularity from horizon to horizon. We envisage that some operations may be
from fixed installations with the antennas mounted permanently but some will
be temporary - perhaps hand held or bolted to a step ladder or similar.
We know there are many AMSAT members around the globe with great experience
in this field and, we suspect, with some strongly held views. So please let
us have some constructive input about which type is likely to be best for
this purpose - your comments, ideas and lessons learnt will be very valuable
for us.
Thanks in advance for your support
73
Graham
G3VZV - for the FUNcube Project team
As part of the FUNcube project we need to decide which is going to be the
best antenna to propose for use at schools and colleges to receives the
145MHz downlink signals from both FUNcube-1 and FUNcube-2 on UKube after
launch.
Both spacecraft will be transmitting approx 300mW of BPSK 1k2 telemetry with
FEC ? FC1- will be using a dipole antenna and has passive magnetic attitude
control. FC-2 on UKube will use a single monopole antenna and the spacecraft
is intended to have active attitude control to ensure that the deployed
solar panels are illuminated and that the face with the S band patch is
usually earth pointing.
We believe that the resultant signal should be easily usable using an
omnidirectional antenna but the questions is which would be the best type to
use. Obviously ease of construction, cost, robustness and safety in a school
environment will also be important factors as well as suitable ?gain? and
circularity from horizon to horizon.
We know there are many AMSAT members with experience in this field and, we
suspect, some strongly held views but all constructive input would be very
welcome.
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 5
Date: Tue, 9 Apr 2013 19:39:55 -0500
From: Gary Mayfield <gary_mayfield@xxxxxxx.xxx>
To: Graham Shirville <g.shirville@xxxxxxxxxx.xxx>,
"amsat-bb@xxxxx.xxxxx<xxxxxxxx@xxxxx.xxx>
Subject: [amsat-bb] Re: FUNcube Project - Your advice requested
Message-ID: <BAY173-W4D0633D544A65A309D1038AC70@xxx.xxx>
Content-Type: text/plain; charset="Windows-1252"
Graham, Bob's advice is good. I might add you should recommend more
antenna than you think you will need. There really is no such thing as too
much antenna (or too much signal). Nothing creates a more Kohoutek like
experience than marginal or no signals. I would recommend a small beam
(three or more elements) as the minimum antenna. The beamwidth is quite
wide and hand pointing is pretty easy. I have spent a lot of time
elmering folks who thought they were going to hear and work hamsats with
rubber ducks on their hand helds, or colinears on the end of 100 feet of
RG-58. Be clear the antenna/feedline makes or breaks the system.
Experienced operators tend to use the best antennas their space, money and
other constraints allow. Just my thoughts after more than 20 years of
satellite operation. 73, Joe kk0sd
> From: g.shirville@xxxxxxxxxx.xxx
> To: amsat-bb@xxxxx.xxx
> Date: Tue, 9 Apr 2013 20:46:59 +0100
> Subject: [amsat-bb] FUNcube Project - Your advice requested
>
> Hi All,
>
> As part of the FUNcube project we now need to urgently decide which is going
> to be the best type of antenna to propose for use at schools and colleges to
> receive the 145MHz downlink signals from both FUNcube-1 and FUNcube-2 on
> UKube after launch.
>
> Both spacecraft will be transmitting approx 300mW of BPSK 1k2 telemetry with
> FEC ? FC1- will be using a dipole antenna and will have passive magnetic
> attitude control. FC-2 on UKube will use a single monopole antenna and the
> spacecraft is intended to have active attitude control. This is primarily to
> ensure that the deployed solar panels are illuminated and that the face with
> the S band patch is usually earth pointing.
>
> We believe that the resultant signal should be easily usable using an
> omnidirectional antenna but the questions is which would be the best type to
> use. Obviously ease of construction, cost, robustness and safety in a school
> environment will also be important factors as well as suitable ?gain? and
> circularity from horizon to horizon. We envisage that some operations may be
> from fixed installations with the antennas mounted permanently but some will
> be temporary - perhaps hand held or bolted to a step ladder or similar.
>
> We know there are many AMSAT members around the globe with great experience
> in this field and, we suspect, with some strongly held views. So please let
> us have some constructive input about which type is likely to be best for
> this purpose - your comments, ideas and lessons learnt will be very valuable
> for us.
>
> Thanks in advance for your support
>
> 73
>
> Graham
> G3VZV - for the FUNcube Project team
>
>
>
>
>
>
>
>
>
>
>
>
>
> As part of the FUNcube project we need to decide which is going to be the
> best antenna to propose for use at schools and colleges to receives the
> 145MHz downlink signals from both FUNcube-1 and FUNcube-2 on UKube after
> launch.
>
>
>
>
>
>
>
> Both spacecraft will be transmitting approx 300mW of BPSK 1k2 telemetry with
> FEC ? FC1- will be using a dipole antenna and has passive magnetic attitude
> control. FC-2 on UKube will use a single monopole antenna and the spacecraft
> is intended to have active attitude control to ensure that the deployed
> solar panels are illuminated and that the face with the S band patch is
> usually earth pointing.
>
>
>
>
>
>
>
> We believe that the resultant signal should be easily usable using an
> omnidirectional antenna but the questions is which would be the best type to
> use. Obviously ease of construction, cost, robustness and safety in a school
> environment will also be important factors as well as suitable ?gain? and
> circularity from horizon to horizon.
>
>
>
>
>
>
>
> We know there are many AMSAT members with experience in this field and, we
> suspect, some strongly held views but all constructive input would be very
> welcome.
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 6
Date: Tue, 9 Apr 2013 22:48:15 -0500
From: "George Henry" <ka3hsw@xxx.xxx>
To: "Martha" <martha@xxxxx.xxx>, "AMSAT BB" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: OFFICE CLOSED
Message-ID: <90F2AC1C80B74120BB66F7A911269A94@xxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Enjoy, Martha - it is WELL deserved!!!
73,
George, KA3HSW
----- Original Message -----
From: "Martha" <martha@xxxxx.xxx>
To: "AMSAT BB" <amsat-bb@xxxxx.xxx>
Sent: Tuesday, April 09, 2013 4:02 PM
Subject: [amsat-bb] OFFICE CLOSED
> The AMSAT office will be closed from Wednesday, April 10th to Monday April
> 15th. I am taking a birthday holiday to Florida
>
> --
> 73- Martha
------------------------------
Message: 7
Date: Wed, 10 Apr 2013 06:48:02 -0500
From: K4FEG <K4FEG@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] AO7 Mode Switch
Message-ID: <51655172.20907@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
/*For those who wonder about such things, the Mode switch for AO7 is
occurring at approximately 10:47:15UTC.*//*
*/
I was listening for Paul, 2M1EUB/P on AO7 this morning and AO7 was still
in Mode A when I came into the footprint, I listened and called for Paul
near center frequency until he was out of the satellite and then I just
waited to see when the satellite switched mode.
As I stated it happened at about 10:47:UTC I did not have my system
clock synchronized so my time may be off a bit.
I just thought some of those who keep up with such things might be
interested!
Good Day all! & 73;
Frank;
K4FEG
EM55aj85ta
------------------------------
Message: 8
Date: Wed, 10 Apr 2013 14:16:46 +0200
From: PE0SAT | Amateur Radio <pe0sat@xxxxx.xx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: AO7 Mode Switch
Message-ID: <e78658083205049f57c1f18186c64c8b@xxxxx.xx>
Content-Type: text/plain; charset=UTF-8; format=flowed
Hi Frank,
Thanks for sharing this information.
73 Jan PE0SAT
On 10-04-2013 13:48, K4FEG wrote:
> /*For those who wonder about such things, the Mode switch for AO7 is
> occurring at approximately 10:47:15UTC.*//*
> */
> I was listening for Paul, 2M1EUB/P on AO7 this morning and AO7 was
> still in Mode A when I came into the footprint, I listened and called
> for Paul near center frequency until he was out of the satellite and
> then I just waited to see when the satellite switched mode.
>
> As I stated it happened at about 10:47:UTC I did not have my system
> clock synchronized so my time may be off a bit.
>
> I just thought some of those who keep up with such things might be
> interested!
>
> Good Day all! & 73;
>
> Frank;
> K4FEG
> EM55aj85ta
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
> author.
> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
--
With regards PE0SAT
Internet web-page http://www.pe0sat.vgnet.nl/
------------------------------
Message: 9
Date: Wed, 10 Apr 2013 16:38:46 +0100 (BST)
From: paul robinson <pushbiker2004@xxxxx.xx.xx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] UPDATE 2M1EUB/P OPPS IO97CM WORKED
Message-ID:
<1365608326.21023.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
Thanks for the contacts from io97cm today ,now qrt after 4hours my yl had
enough! i worked one pass a07 mode b and 3 passes fo29. k8yse has a
recording on hisweb page? of a qso on fo29 any one interested..73 paul
2M1EUB/P
------------------------------
Message: 10
Date: Wed, 10 Apr 2013 18:47:48 +0100 (BST)
From: paul robinson <pushbiker2004@xxxxx.xx.xx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] ao7 mode switch k4feg-2m1eub/p
Message-ID:
<1365616068.73869.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
frank i was hanging about for the mode switch sorry we didnt make it ,from
io97 im back in 87sq if you abt next 2days de paul 2m1eub/p
------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 8, Issue 112
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