Author Topic: Colinear Antenna for 1090 MHz ADS-B  (Read 165 times)

ChrisSmolinski

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Colinear Antenna for 1090 MHz ADS-B
« on: June 09, 2018, 1606 UTC »
After some hemming and hawing, I built an 8 element colinear antenna for 1090 MHz, following this as a rough guide: https://www.balarad.net

I installed it in place of the ground plane antenna. Here's the resulting range/coverage map from a week's worth of monitoring. I think the range is a little better in some directions. The limited range to the southeast is due to trees some distance away on a ridge, there's nothing I can do about that. Maybe in the winter the range will improve when the trees lose their leaves.



For reference, the range plot for the previous antenna, the ground plane, mounted the same height in the same tree:
Chris Smolinski
Westminster, MD
eQSLs appreciated! Send to: csmolinski@blackcatsystems.com
JRC-NRD 545 / RF Space netSDR / AFE822x / AirSpy HF+ / 670 ft horizontal loop / 500 ft beverage / 43mb sloping folded dipole / Crossed Parallel Loop

Josh

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #1 on: June 10, 2018, 1706 UTC »
Same amp?

ChrisSmolinski

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #2 on: June 10, 2018, 1730 UTC »
Yes, same amp.
Chris Smolinski
Westminster, MD
eQSLs appreciated! Send to: csmolinski@blackcatsystems.com
JRC-NRD 545 / RF Space netSDR / AFE822x / AirSpy HF+ / 670 ft horizontal loop / 500 ft beverage / 43mb sloping folded dipole / Crossed Parallel Loop

ThElectriCat

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #3 on: June 11, 2018, 1712 UTC »
Did you use standard 75 ohm tv coax? or something else, I have built a couple of these antennas for the 2.4 Ghz ISM band, but never had any better signal than a single dipole, And I was using fancy PTFE/silver Coax.
wj DMS-105a-2, and whatever wire, loop, or other antenna I can get my hands on

ChrisSmolinski

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #4 on: June 11, 2018, 1727 UTC »
Yes, just RG-6 coax. I think the Amazon brand, in fact.
Chris Smolinski
Westminster, MD
eQSLs appreciated! Send to: csmolinski@blackcatsystems.com
JRC-NRD 545 / RF Space netSDR / AFE822x / AirSpy HF+ / 670 ft horizontal loop / 500 ft beverage / 43mb sloping folded dipole / Crossed Parallel Loop

ThElectriCat

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #5 on: June 11, 2018, 1816 UTC »
Thanks, I guess I'll have to try again.
wj DMS-105a-2, and whatever wire, loop, or other antenna I can get my hands on

Josh

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #6 on: June 11, 2018, 1951 UTC »
Have you remoted a dongle up there right at the antenna? That may show some difference in performance greater than switching antennas.

ThElectriCat

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #7 on: June 11, 2018, 2018 UTC »
The signal is being received by an HP spectrum analyzer, and both the antennas were separated from the receiver by about 6 feet of Andrew 1/2 inch Heliax, so I'm pretty sure I just made an error in the construction of the collinear, ad both a dipole and a discone outperform it.
wj DMS-105a-2, and whatever wire, loop, or other antenna I can get my hands on

ChrisSmolinski

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #8 on: June 11, 2018, 2044 UTC »
I'm using an AirSpy, not an RTL dongle. I don't think I am putting that up in a tree  ;D
Chris Smolinski
Westminster, MD
eQSLs appreciated! Send to: csmolinski@blackcatsystems.com
JRC-NRD 545 / RF Space netSDR / AFE822x / AirSpy HF+ / 670 ft horizontal loop / 500 ft beverage / 43mb sloping folded dipole / Crossed Parallel Loop

Josh

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Re: Colinear Antenna for 1090 MHz ADS-B
« Reply #9 on: June 12, 2018, 1715 UTC »
I'm using an AirSpy, not an RTL dongle. I don't think I am putting that up in a tree  ;D


Awww. I bet Carl would send you a v3 dongle to do some remote sdr testing if you wrote the results up into a nice report.