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2.4 GHz contact in Southern Tasmania over mountains

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2.4 GHz contact in Southern Tasmania over mountains
VK7HH Offline
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#1
04-08-2019, 12:33 PM
An on air contact with my 2.4 gigahertz transverter and FT817. Earlier in the day we had confirmed that Richard VK7ZBX's system was also working. The path is not line of sight and is over 1200m (4000 feet) mountains. Amazing signal considering the path and the location of my grid pack.


[Video: https://www.youtube.com/watch?v=h23DxIYwp5Y]
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VK3RX Offline
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#2
04-08-2019, 02:57 PM
Very interesting Smile

Some reflection off something at the top of that mountain?

First play I saw about 13 Amps being drawn on TX then second play noticed the dymo tape saying you're running 25 Watts. An old Galaxy antenna? Still see the odd one of those around.

Very nice.
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VK7HH Offline
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#3
05-08-2019, 08:37 AM
(04-08-2019, 02:57 PM)VK3RX Wrote: Very interesting Smile

Some reflection off something at the top of that mountain?

First play I saw about 13 Amps being drawn on TX then second play noticed the dymo tape saying you're running 25 Watts. An old Galaxy antenna? Still see the odd one of those around.

Very nice.

Yes 25W. The Spectrian amp runs on 24V with increased power output. I could get I think 56W when I was testing on the bench, but as most of my gear is 12V I opted for the reduced power for convenience.

The antenna is a TP Link 24dBi grid pack antenna.

A more detailed description is here - 
[Video: https://www.youtube.com/watch?v=ZGLLPUUmhzU]
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VK7HH Offline
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#4
11-08-2019, 08:11 PM
A follow up video from a rainy day in VK7

[Video: https://www.youtube.com/watch?v=y_O1GkazQls]
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VK7HH Offline
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#5
28-08-2019, 11:14 AM
More testing on 3.4 GHz using a WA5VJB PCB antenna as a grid feed

[Video: https://www.youtube.com/watch?v=mSUfKTdSwM4]
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VK3QI
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#6
28-08-2019, 11:12 PM
VK7HH Wrote:More testing on 3.4 GHz using a WA5VJB PCB antenna as a grid feed

[Video: https://www.youtube.com/watch?v=mSUfKTdSwM4]
Hayden,

There are few tests you can do.

(1) rotate the antenna in the horizontal and see what the beam width is

(2)  see if there are any lobes - these will be evident if the feed is not quite in the correct position

(3) move the LP in and out to try and minimise any lobes  -   anything better than  -20dB is good!

(4)  rotate the antenna in the vertical and check what the vertical beamwidth is.

(5) given the symmetry of the feed, there  is nothing you can do about any lobes in the vertical.

(6)  Check what the conduit is doing RF wise - it might be affecting the return loss on some bands.


Perhaps your VK7 friend can put a constant carrier up on FM at low power for you to work with.


Cheers

Peter  VK3QI
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