Interference expected?

[SirElliott]

I am in the process of applying for the Flightradar24 host package in Central Washington State. I currently have a 4.5 meter mast on the roof.

Pointed north (3 degrees) on that mast is a Wilson 304475 wide band yagi directional antenna connected to a Wilson cellular repeater for 3G 824-894 and 1850-1990 MHz. (Verizon 3g)

Below that pointed southeast (140 degrees) is a Ubiquiti NanoStation loco M5 (5Ghz) point to point WiFi bridge pointed to an identical station about 1 km away. Both systems currently work well with no interference.

Both antennas are mounted low on the mast. The NanoStation is the lowest at maybe .5 meter from the bottom, the Yagi is about .5 meter above that. The mast is empty until the very top where a hardware wind sensor package sits.

Can I mount the supplied antenna (38 cm long external Mode-S antenna with mounting clamps (0dBd gain, 38 cm long,
weather proof) high on the mast? Should I expect to have to install another mast and if so what kind of separation should I try for?

Thanks for your thoughts.
Elliott

[HvdS]

Hi Elliott,

I have a lot of experience with antennas in varying frequency bands in close proximity on the top of ship's wheelhouses or superstructures. If I understand your setup correctly, the Mode S antenna would be 3.5m above the 5 GHz antenna. If that is the case I would expect very acceptable performance of the Mode S installation.

Good Luck,
Henk

[DroidNine]

Hi Elliott,

I have a lot of experience with antennas in varying frequency bands in close proximity on the top of ship's wheelhouses or superstructures. If I understand your setup correctly, the Mode S antenna would be 3.5m above the 5 GHz antenna. If that is the case I would expect very acceptable performance of the Mode S installation.

Good Luck,
Henk

You should be fine with your installation. If you can get the 3m of isolation between the yagi and the mode-S antenna that should be more than sufficient (~70dB vertical isolation). Ensure you are using shielded ethernet cabling and RJ45 connectors for the NanoStation with the drain soldered in.

Is the coax for the 3G equipment grounded properly/at all?

[jasonp]

My site has about 20 radios of various types... About a dozen Ubiquiti radios in 5ghz and 3.65ghz, some Alvarion 5.8/2.4ghz radios, a trango 900mhz radio, VHF AIS receiver, Carlson TVWS radio. I only use shielded (and uv rated) cat5e for the outdoor data cabling, with drain wires to a ground bus bar, and ubiquiti toughconnectors for rj45 ends. No problems with ADS-B receiver function with the flightradar24 supplied hardware (antenna mounted atop the smaller tower). If you have some cheap tv dongle tuner, it could receive interference from having a cheap case.

The directionality of the loco radios is very poor; they put out RF in all directions (but not a ton of it)

IMG_20140914_161808.jpg

I would bet the original poster will be fine.

[SirElliott]

Thank you to all.
I have put the FR24 supplied antenna up in a temporary setup, close to the other antenna. No interference noted.