• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

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    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

You call that a yagi? Now THIS is a yagi !!

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Hi all,
some background to these pictures... this happened a long time ago.
Here in Tasmania (yes, it is a real place, and yes we really do have Tasmanian Devils, but they're nothing like the cartoon depicts - except maybe their eating manners!) the pace of life on this island is a little slow. Not a lot happens here.
We're seperated from the mainland of Australia by a body of water some 280 miles / 450 kilometres span.
Some local scanner enthusiasts knew that, occasionally, strong tropospheric ducting would carry VHF & UHF signals from the mainland of Australia across the water to Tasmania. The city of Melbourne (population approx 4 million) is just on the other side of the water, and so provides a lot of interesting listening compared to our local fare.

Along with a few other scanner enthusiasts, we decided to try a little experiment that - ah - got out of hand somewhat. At a nearby hilltop where I have a repeater located for a private two way radio network, we put up the following yagis, co-phased them using a Wilkinson combiner / divider of my own construction, and fed the lot inside the hut with Belden 9913 air-space coax. Inside, we had a very low noise 1.0dB NF preamp with bandpass filter, and then into a very hot receiver from a two way radio, scanning various UHF frequencies from the mainland - 280 mi / 450 km distant. We found that we didn't need any tropospheric ducting to recieve these signals at all with this setup !!

The co-phased yagis had a gain of approx 22dBd (going on manufacturers specifications) and from field measurements we did, that is pretty close to the mark. The preamp added a further 4dB of overall performance (not gain).

We even took it one step further by re-transmitting what was heard via a low power licence free frequency. Unsuspecting scanner users who stumbled upon the licence-free freq. couldn't understand / believe what was going on! hehe.

Sadly, this was all dismantled about 3 years ago, but it was a fun thing to try out.





 

SAR923

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#2
Pretty amazing set up. I'm sure it helped that you going over water but 280 miles is still quite a feat for UHF, even with the array, great coax, amp, and professional receiver. How come it got taken down? Seems like all the scanner listeners in Tasmania would have wanted to see it stay up.
 
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