Hi all...
I was looking around a site that offers a 23cm EME Beacon, internet controlled....and found this on the site.....audio of received CW using his Horn antenna from inside the house...the antenna looks nice neat and tidy...
Has anyone tried these in the past..? for places where there just is not the room for a dish or multiple yagi's....
It was interesting to know that, with all the interest in antenna noise temperature these days, the horn has a lower noise temp than the dish.......simply because the feed of a dish is looking in the direction of the earth and thus some spillover from outside the dish occurs.....where the horn has the noise temp of basically what it is pointed at...
http://member.eduhi.at/OE5JFL/echo.htm
(bottom of the page)
John
23cm Horn antenna
Re: 23cm Horn antenna
In the true traditions of "string and sealing wax" science 
In this case, "wire and solder"
73, Roger Harrison VK2ZRH
In this case, "wire and solder"
73, Roger Harrison VK2ZRH
Re: 23cm Horn antenna
That's an interesting find, John.
It looks like a real bugger to make?
I wonder how robust it is, and how it survives the wind?
(Or being transported, for activity day use)
Most of it's strength appears to rely on the mesh.
I went down the traditional route, and use a 27 element loop yagi.
With out favorable exchange rate though, I am drooling over an M2 35 element yagi... very solid construction, and inherently more robust than the loop yagi.
It looks like a real bugger to make?
I wonder how robust it is, and how it survives the wind?
(Or being transported, for activity day use)
Most of it's strength appears to rely on the mesh.
I went down the traditional route, and use a 27 element loop yagi.
With out favorable exchange rate though, I am drooling over an M2 35 element yagi... very solid construction, and inherently more robust than the loop yagi.
Adam, Brisbane
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VK2GOM
Re: 23cm Horn antenna
I'm sure the return loss would change depending on how many lobsters find their way into it
Awesome Rx performance though - I had a listen to the audio files on that page.
73 - Rob VK2GOM / GW0MOH
Awesome Rx performance though - I had a listen to the audio files on that page.
73 - Rob VK2GOM / GW0MOH
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VK2XSO
Re: 23cm Horn antenna
10 watts into a deep fryer basket.
Now I feel like I haven't contributed enough with some whacky ideas.
Now I feel like I haven't contributed enough with some whacky ideas.
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VK2FAK
Re: 23cm Horn antenna
Hi all....
From my reading of the web page, the signal was better when the horn was placed outside.
This is not so much of a whacky antenna, but this is just an extension of a Feed Horn I would guess has been used by many in the past....the W2IMU dish feed horn, all that was added is the skirting to open it up to 0.55m and thus i think increase the gain...
So anyone who has made the original feed horn would know how to make this also.
How would 2 of these antenna side by side go.....the big advantage would be the very reduced weight compared to a dish, mind you, you may lose that advantage in the connecting cables and such.......and damn, on bad days you can put it in the living room and point it out the doors...........I dare you dish guys to try that.....haha
John
From my reading of the web page, the signal was better when the horn was placed outside.
This is not so much of a whacky antenna, but this is just an extension of a Feed Horn I would guess has been used by many in the past....the W2IMU dish feed horn, all that was added is the skirting to open it up to 0.55m and thus i think increase the gain...
So anyone who has made the original feed horn would know how to make this also.
How would 2 of these antenna side by side go.....the big advantage would be the very reduced weight compared to a dish, mind you, you may lose that advantage in the connecting cables and such.......and damn, on bad days you can put it in the living room and point it out the doors...........I dare you dish guys to try that.....haha
John
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VK2JDS
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Re: 23cm Horn antenna
The feed is just that . a feed for a big dish, not a replacement for a big dish.
The photo shows him using the feed pointed out his window to hear the high powered sidesplash from his real eme dish setup sited only 3km from his house.
It's circularly polarised and adding the extra section of mesh on the end results in quite a narrowed pattern compared to the standard feed.
This then is reducing the illumination of the EME beacon dish (down to 2 feet) when he fits it to the dish.
Hence his experiment is that reducing illumination and increasing transmit power would correlate to same echo strength.
the bit at the end about seeing echos directly i am still thinking about.
73 Dave
The photo shows him using the feed pointed out his window to hear the high powered sidesplash from his real eme dish setup sited only 3km from his house.
It's circularly polarised and adding the extra section of mesh on the end results in quite a narrowed pattern compared to the standard feed.
This then is reducing the illumination of the EME beacon dish (down to 2 feet) when he fits it to the dish.
Hence his experiment is that reducing illumination and increasing transmit power would correlate to same echo strength.
the bit at the end about seeing echos directly i am still thinking about.
73 Dave
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VK2FAK
Re: 23cm Horn antenna
Hi all.....
No its not a replacement for a big dish......but a Horn is an antenna in its own right...
The horn you see he calls his test horn......the waterfall screen shot shows the delay between sent and received so it is the moon echo.......he says the horn is close enough to his dish to give that first pulse on the waterfall....the second pulse showing is, I guess the moon echo....
http://www.qsl.net/oe5jfl/moonecho.htm
Horns have been around a long time in there own right.....not just fitted to dishes...
Circular polarization is important also, and seems to be achieved by that Horn with gain and short length......
John
No its not a replacement for a big dish......but a Horn is an antenna in its own right...
The horn you see he calls his test horn......the waterfall screen shot shows the delay between sent and received so it is the moon echo.......he says the horn is close enough to his dish to give that first pulse on the waterfall....the second pulse showing is, I guess the moon echo....
http://www.qsl.net/oe5jfl/moonecho.htm
Horns have been around a long time in there own right.....not just fitted to dishes...
Circular polarization is important also, and seems to be achieved by that Horn with gain and short length......
John
Re: 23cm Horn antenna, can we truncate
Hi,
Can we truncate the "point" of a horn and place a "flat" antenna there?
So, I did it.
http://www.unixservice.com.au/hamradio/antenna
It's pointed east at the moon, from Emu Plains,
Now, all I need is WSPR, WSJT, WSJT-X on Linux (Fedora 19 x86_64) working.
We need a Linux audio processing programmer to get ALL sound-cards working by
using "standard" sample-rates of 44100 and 48000 in the above.
Alan VK2ZIW
Can we truncate the "point" of a horn and place a "flat" antenna there?
So, I did it.
http://www.unixservice.com.au/hamradio/antenna
It's pointed east at the moon, from Emu Plains,
Now, all I need is WSPR, WSJT, WSJT-X on Linux (Fedora 19 x86_64) working.
We need a Linux audio processing programmer to get ALL sound-cards working by
using "standard" sample-rates of 44100 and 48000 in the above.
Alan VK2ZIW