I use a camera mounted on the support strut of the dish feed. It is pointed at the center of the dish. Then I simply point the dish at the sun and make corrections to az and el until the shadow is exactly in the center of the dish. Then use those corrections in MacDoppler. Works great! No risk to the camera by looking at the sun.
Lou McFadin W5DID w5did@cfl.rr.com
On Sep 11, 2012, at 3:00 PM, amsat-bb-request@amsat.org wrote:
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Today's Topics:
- Re: e: Satellite technical question (i8cvs)
- Re: Camera on an antenna (i8cvs)
- Re: Camera on an antenna (Robert Bruninga)
- Re: PROITERES (Simon Pack)
- Microwave Spectrum Issues at EME 2012 (Trevor .)
- Re: Camera on an antenna (i8cvs)
- Re: PROITERES (GW1FKY@aol.com)
- Proiteres (PY5LF)
- AMSAT-UK Symposium streaming this year? (Alan P. Biddle)
- Increasing Popularity Of CubeSats (B J)
Message: 1 Date: Mon, 10 Sep 2012 23:31:55 +0200 From: "i8cvs" domenico.i8cvs@tin.it To: "Nick Pugh" quadpugh@bellsouth.net, "Amsat - BBs" amsat-bb@amsat.org Subject: [amsat-bb] Re: e: Satellite technical question Message-ID: 00a801cd8f9b$b42c08e0$0301a8c0@b3o7f1 Content-Type: text/plain; charset="iso-8859-1"
Hi Nick ,
The equivalent noise temperature of an antenna do not depends by it's phisical temperature but only by the noise temperature emitted by the object that the main lobe of the antenna is looking.
The equivalent noise temperature of the antenna radiation resistance do not depends by the phisical temperature of the antenna but only by the noise temperature emitted by the object that the main lobe of the antenna is looking.
As an example, if you install a parabolic dish on the Nort Pool at very low temperature and a similar parabolic dish in the desert at the equator at high temperature and you point both the antennas toward the Sun than the received Sun Noise will be the same no matter the structural temperature of both dishes will be.
Of coarse only the phisical temperature of the antenna preamplifiers and all the associated receivers phisical temperature must be the same.
73" de
i8CVS Domenico
----- Original Message ----- From: "Nick Pugh" quadpugh@bellsouth.net To: "'Nick Pugh'" quadpugh@bellsouth.net; amsat-bb@amsat.org Sent: Sunday, September 09, 2012 8:15 PM Subject: [amsat-bb] Re: e: Satellite technical question
I am sorry I did not mean the physical temperature What I wanted is the equivalent noise temperature.
Thanks for those who replied
nick
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Nick Pugh Sent: Sunday, September 09, 2012 10:07 AM To: amsat-bb@amsat.org Subject: [amsat-bb] e: Satellite technical question
e: Satellite technical question
Assume a cubesat with a monopole ? wave antenna at 400 mhz. The satellite is in full sun with a 500km orbit. What is the antenna temperature in full sun and in eclipse?
TNX in advance
Nick CAPE Team
Message: 2 Date: Mon, 10 Sep 2012 23:51:49 +0200 From: "i8cvs" domenico.i8cvs@tin.it To: "James Luhn" luhn@wt.net, "Amsat - BBs" amsat-bb@amsat.org Subject: [amsat-bb] Re: Camera on an antenna Message-ID: 00e601cd8f9e$7b8aa160$0301a8c0@b3o7f1 Content-Type: text/plain; charset="iso-8859-1"
Hi James, W5AOO
To mount a camera on a beam in order to locate the moon to work EME is a very bad procedure.
The correct procedure is to point the antenna system toward the Sun and get the maximum Sun Noise on receiver.
As soon the maximum Sun Noise is received please calibrate the Azimuth and the Elevation of your control box relative to the Sun position.
If the control box is well calibrated with the position of the Sun than it will be very well calibrated also for the Moon position.
I use the above procedure for my antenna system and I am very happy with it.
73" de
i8CVS Domenico
----- Original Message ----- From: "James Luhn" luhn@wt.net To: amsat-bb@amsat.org Sent: Saturday, September 08, 2012 7:22 PM Subject: [amsat-bb] Camera on an antenna
Please don't ya'll laugh too hard at me. Has anyone ever mounted a camera on a beam? Now I am not trying to see AO40, but I would like to simply double check the location of my beam for eme. If anyone has mounted a camera on a beam, I would be interested in what you used. Yes, I know all about beam width vs the moon. I just hate to call CQ with my beams pointed to the ground due to some Murphy type of failure.
73, -james W5AOO
Message: 3 Date: Mon, 10 Sep 2012 18:20:17 -0400 From: Robert Bruninga bruninga@usna.edu To: i8cvs domenico.i8cvs@tin.it, James Luhn luhn@wt.net, Amsat - BBs amsat-bb@amsat.org Subject: [amsat-bb] Re: Camera on an antenna Message-ID: 1b5ce3bfd15b891e21cf699dcd03b84f@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1
I'd say that differently...
Nothing wrong with using the camera. But your point is well taken to calibrate the camera to the BEAM by first pointing at the sun. Then (if your camera survives) the camera is a perfectly good aiming device for the moon and it eliminates any errors in the Antenna controller and pots. Bob
-----Original Message-----
To mount a camera on a beam in order to locate the moon to work EME is a very bad procedure.
The correct procedure is to point the antenna system toward the Sun and get the maximum Sun Noise on receiver.
As soon the maximum Sun Noise is received please calibrate the Azimuth and the Elevation of your control box relative to the Sun position.
----- Original Message ----- From: "James Luhn" luhn@wt.net To: amsat-bb@amsat.org Sent: Saturday, September 08, 2012 7:22 PM Subject: [amsat-bb] Camera on an antenna
Please don't ya'll laugh too hard at me. Has anyone ever mounted a camera on a beam? Now I am not trying to see AO40, but I would like to simply double check the location of my beam for eme. If anyone has mounted a camera on a beam, I would be interested in what you used. Yes, I know all about beam width vs the moon. I just hate to call CQ with my beams pointed to the ground due to some Murphy type of failure.
73, -james W5AOO
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Message: 4 Date: Mon, 10 Sep 2012 23:54:22 +0100 From: "Simon Pack" simon@pack.demon.co.uk To: amsat-bb@amsat.org Subject: [amsat-bb] Re: PROITERES Message-ID: 1AB624654F2949D5A4A7F6F2BD32D0A7@server Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original
Hi All,
I too was listening for PROITERES, and made a recording today (Sep 10th 11:15UTC) using my FunCube Dongle. Looking at the spectrum display, I could see the distinctive pattern of two satellites transmitting. It turns out that the orbit of SEEDS II (CO-66) was almost in perfect alignment with PROITERES, and was also transmitting its morse code beacon on 437.485MHz. I heard 'JQ1YGU SEEDS G4 3475BFB0 D83 FFE CCA 189 8ED 35F' etc. from SEEDS. See http://cubesat.aero.cst.nihon-u.ac.jp/english/seeds_2_e.html
It is possible that some people listening for PROITERES today have actually mistakenly heard SEEDS II, as I found it a few dB stronger at times. The two satellites will drift apart over the next 2 days.
73's Simon G7WIQ
Message: 5 Date: Mon, 10 Sep 2012 23:54:43 +0100 (BST) From: "Trevor ." m5aka@yahoo.co.uk To: amsat-bb@amsat.org Subject: [amsat-bb] Microwave Spectrum Issues at EME 2012 Message-ID: 1347317683.71911.YahooMailClassic@web132205.mail.ird.yahoo.com Content-Type: text/plain; charset=utf-8
The spectrum issues faced by moon-bounce (EME) operators are similar to those affecting the Amateur-satellite Service, see this video made by volunteers from the British Amateur Television Club (BATC)
http://www.uk.amsat.org/?p=10253
73 Trevor M5AKA
Message: 6 Date: Tue, 11 Sep 2012 01:21:58 +0200 From: "i8cvs" domenico.i8cvs@tin.it To: "Robert Bruninga" bruninga@usna.edu, "James Luhn" luhn@wt.net, "Amsat - BBs" amsat-bb@amsat.org Subject: [amsat-bb] Re: Camera on an antenna Message-ID: 001501cd8fab$14e76120$0301a8c0@b3o7f1 Content-Type: text/plain; charset="iso-8859-1"
Hi Bob,
Using a calibrated camera on the Sun is a good system to point the antenna on the Moon only when there are no clods and when the sky is clear.
On the other side a well calibrated control box on the Sun Noise is a goood system to point the antenna at the Moon with any wheader condition even with clods and this make the difference.
73" de
i8CVS Domenico
----- Original Message ----- From: "Robert Bruninga" bruninga@usna.edu To: "i8cvs" domenico.i8cvs@tin.it; "James Luhn" luhn@wt.net; "Amsat - BBs" amsat-bb@amsat.org Sent: Tuesday, September 11, 2012 12:20 AM Subject: RE: [amsat-bb] Re: Camera on an antenna
I'd say that differently...
Nothing wrong with using the camera. But your point is well taken to calibrate the camera to the BEAM by first pointing at the sun. Then (if your camera survives) the camera is a perfectly good aiming device for the moon and it eliminates any errors in the Antenna controller and pots. Bob
-----Original Message-----
To mount a camera on a beam in order to locate the moon to work EME is a very bad procedure.
The correct procedure is to point the antenna system toward the Sun and get the maximum Sun Noise on receiver.
As soon the maximum Sun Noise is received please calibrate the Azimuth and the Elevation of your control box relative to the Sun position.
----- Original Message ----- From: "James Luhn" luhn@wt.net To: amsat-bb@amsat.org Sent: Saturday, September 08, 2012 7:22 PM Subject: [amsat-bb] Camera on an antenna
Please don't ya'll laugh too hard at me. Has anyone ever mounted a camera on a beam? Now I am not trying to see AO40, but I would like to simply double check the location of my beam for eme. If anyone has mounted a camera on a beam, I would be interested in what you used. Yes, I know all about beam width vs the moon. I just hate to call CQ with my beams pointed to the ground due to some Murphy type of failure.
73, -james W5AOO
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Message: 7 Date: Mon, 10 Sep 2012 20:49:42 -0400 (EDT) From: GW1FKY@aol.com To: simon@pack.demon.co.uk, amsat-bb@amsat.org Subject: [amsat-bb] Re: PROITERES Message-ID: 5f53.664a2d51.3d7fe4a6@aol.com Content-Type: text/plain; charset="US-ASCII"
Hi Simon, Thanks for the clarification - That was exactly what I experienced and was rather confused until I played back a short recording and realised that I was not having a receiver problem. Regards Ken GW1FKY
Message: 8 Date: Mon, 10 Sep 2012 22:44:10 -0300 From: "PY5LF" py5lf@falautomation.com.br To: AMSAT-BB@amsat.org Subject: [amsat-bb] Proiteres Message-ID: 002c01cd8fbe$f21c1fa0$d6545ee0$@falautomation.com.br Content-Type: text/plain; charset="us-ascii"
Hi
Proiteres signal heard a few minutes ago ;
http://www.youtube.com/watch?v=Dx4WnoQ_CTk
73
PY5LF
Luciano Fabricio
Curitiba-PR-BR GG54jm
Message: 9 Date: Tue, 11 Sep 2012 08:06:42 -0500 From: "Alan P. Biddle" APBIDDLE@UNITED.NET To: "AMSAT-BB" amsat-bb@amsat.org Subject: [amsat-bb] AMSAT-UK Symposium streaming this year? Message-ID: 5E54F74916E248BA9A991BF71C2C84AB@WA4SCA Content-Type: text/plain; charset="us-ascii"
Hi,
In the past, BATC has streamed the symposium. Will they be doing so this year?
Alan WA4SCA
We haven haven't got the money, so we we've got to think.
Lord Rutherford
Message: 10 Date: Tue, 11 Sep 2012 16:03:32 +0000 From: B J va6bmj@gmail.com To: amsat-bb amsat-bb@amsat.org Subject: [amsat-bb] Increasing Popularity Of CubeSats Message-ID: CAP7QzkMNHu5wCE7O8WGQB8xXAE8vsNJ2N+3_BKCuAttyLOM27A@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1
http://thespacereview.com/article/2155/1
73s
Bernhard VA6BMJ @ DO33FL
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End of AMSAT-BB Digest, Vol 7, Issue 295
----- Original Message ----- From: "Louis McFadin" w5did@mac.com To: amsat-bb@amsat.org Sent: Wednesday, September 12, 2012 3:37 AM Subject: [amsat-bb] Re: Camera on antenna
I use a camera mounted on the support strut of the dish feed. It is pointed at the center of the dish. Then I simply point the dish at the sun and make corrections to az and el until the shadow is exactly in the center of the dish. Then use those corrections in MacDoppler. Works great! No risk to the camera by looking at the sun.
Lou McFadin W5DID w5did@cfl.rr.com
Hi Lou, W5DID
Using the Sun light and point a camera on the Sun is not a good procedure to calibrate the pointing of a dish for radio frequency signals because it is possible that the radio frequency feed is mounted shifted a fraction of degree making a big unwanted squint angle.
Depending on the squint angle of the radio frequency feed with respect to the dish focal point it make a wrong pointing so that using the Sun light and a camera you believe that your dish is looking exactly at the Sun but in reality it can be not exactly pointed to get a radio frequency signal source like the Sun Noise.
Particularly using large high gain dishes with sharp radiation lobe the correct procedure is to calibrate the pointing vector of the dish to the Sun using the Sun Noise and not a camera pointed to the Sun light.
The correct procedure is to use the Sun Noise to calibrate antennas and Sun light to calibrate optical telescopes.
Also to work EME with high gain dishes with narrow main lobe the Azimut and Elevation indication must be made not using position potentiometers but more sophisticated and precision devices like position resolvers, or position absolute encoders or selsyn indicators who permits high and constant resolution of fraction degrees for many years.
For my 1.2 meters dish at 2.4 and 10.5 GHz I use not position potentiometers but 2" surplus position selsyn motors originally used to point guns on board of ships during the WWII
73" de
i8CVS Domenico
participants (2)
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i8cvs -
Louis McFadin