| |
CX2SA > SATDIG 19.02.13 21:01l 428 Lines 14372 Bytes #999 (0) @ WW
BID : AMSATBB853
Read: GUEST
Subj: AMSAT-BB-digest V8 53
Path: IZ3LSV<IV3YXW<HB9TVW<DB0ANF<CX2SA
Sent: 130219/2001Z @:CX2SA.SAL.URY.SA #:3580 [Salto] FBB7.00e $:AMSATBB853
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: QFHA for SO-50... polarization issue ??? (Ib Christoffersen)
2. Re: QFHA for SO-50... polarization issue ???
(Ing. Pavel Milanes Costa)
3. Re: Congratulations to Jim Adams, K0BAM (Jim Adams)
4. Re: Congratulations to Jim Adams, K0BAM (Rick Tejera)
5. Re: QFHA for SO-50... polarization issue ??? (i8cvs)
6. John Heath G7HIA R.I.P. (Robert Turlington)
7. ARISS contact planned February 19, 2013 with school in Greece
(Alex Deligiannis)
8. Article on ShindaiSat microsatellite (Trevor .)
9. Seeking used FT-857D for mobile sat use (Clayton Coleman)
10. ISS communications glitch (Alan)
11. Re: ARISS contact planned February 19, 2013 with school in
Greece (jeffk13057@xxxxx.xxxx
----------------------------------------------------------------------
Message: 1
Date: Mon, 18 Feb 2013 21:15:57 +0100
From: "Ib Christoffersen" <oz1my@xxxxxx.xx>
To: "'Ing. Pavel Milanes Costa'" <pavel@xxxxx.xx>,
<amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: QFHA for SO-50... polarization issue ???
Message-ID: <2AC7660866624B2CA7CDBD4BD96678BC@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Pavel,
The issue may not be the antenna - but SO-50.
The antennas are linear - but the received signal strength can vary a lot if
you have just RHCP or LHCP.
During passes here in Copenhagen, Denmark I experience large differences in
signal strength which can be counteracted by changing polarity from RHCP to
LHCP during the pass.
With large changes I mean from nothing to 59 signals.
Hope that helps.
73 de OZ1MY/Ib
-----Oprindelig meddelelse-----
Fra: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx P? vegne
af Ing. Pavel Milanes Costa
Sendt: 17 February 2013 05:22
Til: amsat-bb@xxxxx.xxx
Emne: [amsat-bb] QFHA for SO-50... polarization issue ???
This weekend I tested a Quadrifiliar Helicoidal Antenna for 70cm (LHCP)
I designed it by the online calculations of jcoppens on the internet...
It is a 1/2 turn and 1 lambda, about 5 meters of elevation with ~25 cm
of RG-58U (a section of it is coiled to form a balum) and then ~15
meters of A.H. LDF4-50A down to the shack directly to the radio, of
course BNC to N adapter on the antenna and N to PL259 on the radio
side... It's at mast top.
Results are good... In passes of over 20 degrees (almost the real
horizon here) I have a good copy, until... TCA, in which I lost the
signal completely...
TCA = Time of Closest Approach.
In northbound passes (I've not tested it in southbound) it work as I
just said...
I have been reading and investigating this strange issue and I think it
is due to polarization...
I had read that SO-50 is linear polarized on 2m AND 70cm with aprox 45
degrees each other...
Then Linear to LHCP in the worst case is 3dB loss (half power) but
consistent over the entire pass... or have SO-50 some
circular/elliptical component in it's signals that renders useless the
antenna after TCA? spin maybe?
There is any chapter of the book I missed or other variable(s) that I
have not taking into account here?
Any comment, link or other kinds of help are welcomed..
73 de CO7WT.
------------------------------
Message: 2
Date: Mon, 18 Feb 2013 15:29:01 -0500
From: "Ing. Pavel Milanes Costa" <pavel@xxxxx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: QFHA for SO-50... polarization issue ???
Message-ID: <51228F0D.4040309@xxxxx.xx>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
Thanks to all for the reply to this thread...
Conclusion is that I need RHCP & LHCP switchable antennas...
And my antenna is working good... but I'm reading an article Art send me
to improve my knowledge about QFHA...
73 and Thanks to all.
El 16/02/13 23:21, Ing. Pavel Milanes Costa escribi?:
> This weekend I tested a Quadrifiliar Helicoidal Antenna for 70cm (LHCP)
>
> I designed it by the online calculations of jcoppens on the internet...
>
> It is a 1/2 turn and 1 lambda, about 5 meters of elevation with ~25 cm
> of RG-58U (a section of it is coiled to form a balum) and then ~15
> meters of A.H. LDF4-50A down to the shack directly to the radio, of
> course BNC to N adapter on the antenna and N to PL259 on the radio
> side... It's at mast top.
>
> Results are good... In passes of over 20 degrees (almost the real
> horizon here) I have a good copy, until... TCA, in which I lost the
> signal completely...
>
> TCA = Time of Closest Approach.
>
> In northbound passes (I've not tested it in southbound) it work as I
> just said...
>
> I have been reading and investigating this strange issue and I think
> it is due to polarization...
>
> I had read that SO-50 is linear polarized on 2m AND 70cm with aprox 45
> degrees each other...
>
> Then Linear to LHCP in the worst case is 3dB loss (half power) but
> consistent over the entire pass... or have SO-50 some
> circular/elliptical component in it's signals that renders useless the
> antenna after TCA? spin maybe?
>
> There is any chapter of the book I missed or other variable(s) that I
> have not taking into account here?
>
> Any comment, link or other kinds of help are welcomed..
>
> 73 de CO7WT.
>
>
> _______________________________________________
> 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: 3
Date: Mon, 18 Feb 2013 16:10:27 -0700
From: Jim Adams <jim9251@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Congratulations to Jim Adams, K0BAM
Message-ID:
<CAD6RR8jsyRVVd+EPN3WgA5AwE5EmHx4SJKAmHsGUARYguF2Sfw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Thank you! I sent that photo in on a dare, what a shock it was to see me in
QST!
Jim Adams - K0BAM
------------------------------
Message: 4
Date: Mon, 18 Feb 2013 16:41:29 -0700
From: "Rick Tejera" <saguaroastro@xxx.xxx>
To: "'Jim Adams'" <jim9251@xxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Congratulations to Jim Adams, K0BAM
Message-ID: <000401ce0e31$79d8c9c0$6d8a5d40$@xxx>
Content-Type: text/plain; charset="us-ascii"
I saw it too and meant to mention it, got ties up with Hamfest preparations.
Always nice to a face to the call sign.
73
Rick Tejera (K7TEJ)
Sagauro Astronomy Club
www.saguaroastro.org
Thunderbird Amatuer Radio Club
www.w7tbc.org
30 Meter Digital Group # 5794
Feld Hell Club #3994
OMISS #8629
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Jim Adams
Sent: Monday, 18 February, 2013 16:10
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Congratulations to Jim Adams, K0BAM
Thank you! I sent that photo in on a dare, what a shock it was to see me in
QST!
Jim Adams - K0BAM
_______________________________________________
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, 19 Feb 2013 08:14:30 +0100
From: "i8cvs" <domenico.i8cvs@xxx.xx>
To: "Ing. Pavel Milanes Costa" <pavel@xxxxx.xx>, "Amsat - BBs"
<amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: QFHA for SO-50... polarization issue ???
Message-ID: <002001ce0e70$c407e1e0$0301a8c0@xxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Ing. Pavel Milanes Costa" <pavel@xxxxx.xx>
To: <amsat-bb@xxxxx.xxx>
Sent: Monday, February 18, 2013 9:29 PM
Subject: [amsat-bb] Re: QFHA for SO-50... polarization issue ???
> Thanks to all for the reply to this thread...
>
> Conclusion is that I need RHCP & LHCP switchable antennas...
>
> 73 and Thanks to all.
>
> 73 de CO7WT.
Hi Pavel, CO7WT
The QFHA is not a switchable antenna from RHCP to LHCP because
RHCP is wound with turns conterclockwise and LHCP is wounded with
turns clockwise just the reverse of the classic W8JK helical antenna.
If you like RHCP and LHCP polarizations you need two separate
antennas swichable with a coax relay.
In a separate email I have sent to you the best original article on helix
antennas written by Walter Maxell W2DU.
More information on QFH antennas from W2DU are available here:
http://w2du.com/
73" de i8CVS Domenico
------------------------------
Message: 6
Date: Tue, 19 Feb 2013 13:29:27 +0000
From: Robert Turlington <rob_g8ate@xxxxxxx.xxx>
To: Amsat Buleitin Board <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] John Heath G7HIA R.I.P.
Message-ID: <COL126-W454740E138A6D3798E8D5FC0F50@xxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
I was very saddened to hear that John Heath had passed away over the weekend.
I had come across him about 20yrs ago whilst calling CQ on 2m ssb, it soon
became clear we had the same interest in Amateur Radio Satellites.
John was a very private person and after an exchange of emails last year it
became apparent that his health was declining rapidly but he never let on
about the serious of his condition that's just the sort of man he was.
I think Clive Wallis has posted an exelent epitaph for John which I don't to
intend to elaborate on much more.
I will just like to add that John was a founding member of the National
Space Centre A.R.S here in Leicester and participated in a number of Special
event stations on Amateur satellites :-GB1MSF,GB1WIS,GB5OSO to name but a few.
Although his new QTH in Devon was not very suitable for Satellite operations
he still retained a keen interest in Radi right to the end, indeed in the
last 6 months of last year he was experimenting with kites and wire antennas
and had constructed a QRP kit for HF.
John Heath was a Gentleman in the true sense of the word and a good friend
always willing to help out in any way he could
I will say no more John Heath R.I.P.
Robert G8ATE
------------------------------
Message: 7
Date: Tue, 19 Feb 2013 17:56:34 +0200
From: Alex Deligiannis <sv8qg@xxxxxx.xx>
To: AMSAT-BB@xxxxx.xxx
Subject: [amsat-bb] ARISS contact planned February 19, 2013 with
school in Greece
Message-ID: <5123A0B2.8050400@xxxxxx.xx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
OR4ISS heard laud and clear calling J41ISS many times but the ground
station was absent...
I have the wav from the pass for anyone interesting.
73s
Alex
SV8QG KM39gc
------------------------------
Message: 8
Date: Tue, 19 Feb 2013 16:12:18 +0000 (GMT)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Article on ShindaiSat microsatellite
Message-ID:
<1361290338.13413.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
A good English language article about ShindaiSat is available on the
eoportal site. While the ShindaiSat website implies a 2013 launch the
article says mid-2014 on a H2A with the Global Precipitation Measurement
(GPM) mission.
See http://www.amsat-uk.org/?p=12822
73 Trevor M5AKA
------------------------------
Message: 9
Date: Tue, 19 Feb 2013 11:09:42 -0600
From: Clayton Coleman <kayakfishtx@xxxxx.xxx>
To: AMSAT <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Seeking used FT-857D for mobile sat use
Message-ID:
<CAPovOwc_hLfn_c0mFrd8rZZXV7HKOQ1oqrsgQ+jHRjLmqOjL1w@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
I'm looking for a lightly used Yaesu FT-857D for to work FO-29, VO-52,
and AO-7 mobile. I would prefer it come with separation kit. I'm
only interested in the "D" model. I've been running an IC-910H in the
car but now I'm ready for something SMALLER and more concealable!
Please email me directly off the amsat-bb if you have one on your
shelf collecting dust.
Thank you & 73,
Clayton
W5PFG
------------------------------
Message: 10
Date: Tue, 19 Feb 2013 12:05:34 -0600
From: Alan <wa4sca@xxxxx.xxx>
To: "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] ISS communications glitch
Message-ID: <F185B111047E47E4A24CDCBEECB1BB5A@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
>From CNN:
NASA lost regular communication with the International Space Station on
Tuesday and has since established only limited connections. The space agency
said it was doing a routine update of computer software when communications
were lost, leaving the craft able to communicate only every 90 minutes when
it passes over ground stations in Russia. "This is the same way they used to
do it in the 1960s, with Gemini and Apollo," NASA spokesman Josh Byerly
said. "The crew is working on this, and they'll get it back up and running."
The station, which is carrying one American astronaut and two Russian
cosmonauts, does not appear to be in danger. "It's not a panicked mood that
takes over mission control," Byerly said. "Anybody's who's been here has
seen that." Aboard the station, Commander Kevin Ford told mission control
during a pass over a Russian ground station that the craft is "still flying
straight" and that "everybody's in good shape." The loss in communications
is not considered unprecedented, though it is thought to be a cause for
concern, officials said. The station is the product of a partnership among
16 nations and carries six laboratories for space research.
Alan
WA4SCA
-----------------------------------
Asteroids are Nature's way of asking:
"How's that space program coming along?"
Aaron Williams
------------------------------
Message: 11
Date: Tue, 19 Feb 2013 11:48:13 -0800 (PST)
From: jeffk13057@xxxxx.xxx
To: "sv8qg@xxxxxx.xxx <sv8qg@xxxxxx.xx>, "AMSAT-BB@xxxxx.xxxx
<AMSAT-BB@xxxxx.xxx>
Subject: [amsat-bb] Re: ARISS contact planned February 19, 2013 with
school in Greece
Message-ID: <1361303293.27029.iosMobile@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Interesting. There was a communications failure inboard after a software
upgrade today. <br/><br/>73, <br/><br/>Jeff WB2SYK<br/><br/><br/>Sent from
Yahoo! Mail for iPhone
------------------------------
_______________________________________________
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 53
***************************************
Read previous mail | Read next mail
| |
