I have noticed (when passing by on the train) on top of Strathfield Plaza a strange looking antenna mounted on a pole - possibly a simplified version of a direction finding antenna. It has three horizontal arms, 120 degrees apart with several vertical antennas on each arm. Any suggestions?
Grant
Direction-finding antenna?
Direction-finding antenna?
Professional Scanner nut. Ibis bin chicken of radio scraps
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Scanners:
Uniden 325P2, Whistler TRX-1, GRE PSR800 x 2, Uniden 780 x 3, Uniden 796, Uniden 396 x 2, Uniden 246,
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Re: Direction-finding antenna?
Can you get a photo Grant?
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Bigfella237
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Re: Direction-finding antenna?
Typically, mobile (vehicle mounted) RDF systems will have four or five antennae (per band) spaced according to the required frequency...
...but fixed location arrays usually have many more in order to increase the resolution to compensate for not being able to move and take multiple bearings on the signal source...
And obviously there must be more than just that one site because you need at least two bearings taken from different locations to triangulate the source's location.
My wild guess (pending a photo) is that it may just be some kind of unidirectional dipole setup?
Andrew
...but fixed location arrays usually have many more in order to increase the resolution to compensate for not being able to move and take multiple bearings on the signal source...
And obviously there must be more than just that one site because you need at least two bearings taken from different locations to triangulate the source's location.
My wild guess (pending a photo) is that it may just be some kind of unidirectional dipole setup?
Andrew
Re: Direction-finding antenna?
3 poles? 120 degrees.... Sounds exactly like a mobile phone antenna. Doppler RDF needs at least 4 to work, so it's safe to count out RDF (fancy pictures aside!)
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BrisbaneScan
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Re: Direction-finding antenna?
I got a picture on my samsung but its not that clear. I will try again tomorrow morning on my way home from night shift
Professional Scanner nut. Ibis bin chicken of radio scraps
Scanners:
Uniden 325P2, Whistler TRX-1, GRE PSR800 x 2, Uniden 780 x 3, Uniden 796, Uniden 396 x 2, Uniden 246,
Software:
DSD v2.368, Unitrunker, Trunkview
Scanners:
Uniden 325P2, Whistler TRX-1, GRE PSR800 x 2, Uniden 780 x 3, Uniden 796, Uniden 396 x 2, Uniden 246,
Software:
DSD v2.368, Unitrunker, Trunkview
Re: Direction-finding antenna?
If you want to see what a govt DF antenna install looks like, drive past the "3 swallows" pub on the hume hwy at bankstown and look up at the radio mast behind it.....
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Mike Alpha
- Posts: 672
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Re: Direction-finding antenna?
It's not one of these is it?
Re: Direction-finding antenna?
That looks like it. Pretty well spot on. I suppose there is a perfect good explanation of what it is
Professional Scanner nut. Ibis bin chicken of radio scraps
Scanners:
Uniden 325P2, Whistler TRX-1, GRE PSR800 x 2, Uniden 780 x 3, Uniden 796, Uniden 396 x 2, Uniden 246,
Software:
DSD v2.368, Unitrunker, Trunkview
Scanners:
Uniden 325P2, Whistler TRX-1, GRE PSR800 x 2, Uniden 780 x 3, Uniden 796, Uniden 396 x 2, Uniden 246,
Software:
DSD v2.368, Unitrunker, Trunkview
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Mike Alpha
- Posts: 672
- Joined: Thu Aug 14, 2008 8:22 pm
Re: Direction-finding antenna?
I posted that picture in Feb 2012 and I don't think there was a definite answer to what that antenna is.cartman wrote:That looks like it. Pretty well spot on. I suppose there is a perfect good explanation of what it is
Mike