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Author Topic: makeshift antenna mast at home  (Read 2977 times)

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typist

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makeshift antenna mast at home
« on: August 26, 2010, 07:21:03 AM »
I'm roughly 10nm south of VVNB (Hanoi Noibai). The stock antenna performs well on top of a 120m+ antenna mast which gives me excellent coverage of the airport, and mostly unobstructed line of sight to all other directions. It's no doubt a nearly ideal antenna mast, since the hotel bar on the 30th floor also supplies gin tonic. I'd like to install my radarbox there permanently, but that's another project.

I just tested the stock antenna for 24h at home, on a 4th floor terrace, surrounded by obstructions. Reception is still ok, roughly 70 nm for flights at FL20-40. I receive some random messages down to 1600ft around the airport, but reception is really only reliable above 5000ft. Polar diagram attached.

Todays project is to raise the stock antenna above my own roof using a 6m bamboo pole. I "weatherproofed" the stock antenna with some vaseline, and a childrens balloon stretched over the base and around the cable. A thingy which formerly contained fish oil capsules fits neatly over the top of the pole, I'm going to bolt the ground plane onto it. I'll mount the radarbox 2/3 up the mast, in a formerly airtight lunch box, again bolted to the bamboo pole. I drilled 2 holes into the bottom for the cables (and ventilation), and supported the connectors in styrofoam. 5m powered usb cable to a netbook from there. A 30 min build time antenna mast, ungrounded lightning rod, and static generator all-in-one.

Off to find nuts and bolts...hopefully I'll see somewhat improved reception. If not, I'll forget about mounting a permanent anteanna at home, and keep drinking gin and tonic...
« Last Edit: August 26, 2010, 07:35:22 AM by typist »

typist

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Re: makeshift antenna mast at home
« Reply #1 on: August 26, 2010, 10:21:59 AM »
Raising the stock antenna a few metres above roof level was clearly worth it so far. I immediately picked up flights down to 500ft around the airport, reliably above 1000-2000ft (previously 1500 and 5000 ft respectively). Now I see and airway I had previously missed, roughly 90 nm south of Hanoi, a Cathay Flight from Hong Kong to Bahrain. Then I saw some Lao Airlines AT72, national flights within Laos, these are only mode S though. Looking good. Looks like I'm going to install a permanent antenna at home :)

I'm running radarbox sw inside a virtual machine, and there unfortunately the radarbox network function tends to consume a lot of (limied) resources. I wonder if I am still sharing these flights to the network even if I am not downloading anything. Maybe not? I'll search the forums...


Runway 31

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Re: makeshift antenna mast at home
« Reply #2 on: August 26, 2010, 10:36:26 AM »
Hi Typist,

picking you up on the network.  Can see 3 aircraft at this time.

Alan

typist

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Re: makeshift antenna mast at home
« Reply #3 on: August 26, 2010, 11:15:11 AM »
thanks for letting me know Alan. Radarbox sw just crashed a few times, I increased memory of the virtual machine, hopefully it will run stably now.

updated screenshot...raising the stock antenna just a few metres helped a lot. Maximum range increased from 70 to 130nm. Since the 6m pole worked well, I just bought a 10m bamboo pole for 3$, tomorrow I'll see how much difference that will make. I'm also going to experiment with a larger ground plane for the stock antenna, roughly 30cm.
« Last Edit: August 27, 2010, 09:44:58 AM by typist »

RobinB

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Re: makeshift antenna mast at home
« Reply #4 on: August 27, 2010, 09:57:49 AM »
I would be careful with the sun as it will destroy plastic very quickly.

See if you can out your RB in a metal ali box or a weather proofed electrical junction box.