Antenna Run

So I’m just getting started with ADS-B tracking and have a question regarding the antenna cable. I have a Pi2 and the FA Antenna from Amazon. For testing purposes, I have the Antenna connected to a RG6 adapter, then a short RG6 cable to an RG6/MCX adapter into the RTL. I get great reception right now (using a 5-6 ft. RG6 cable) but as I’m planning the final placement of the antenna, I wanted to know the maximum that I could use without ruining the signal. I have an existing satellite dish on the roof of my house (ideal placement location, highest) that we no longer use. The RG6 goes from the dish down to a utility room in the basement for distribution. If i had to estimate the cable length, I would say it is (at max) 130 feet. Will that length destroy the usable signal? If so, would an amplifier work to resolve this problem? I have an extra cable amplifier that is not longer being used here (I will have to verify the frequency support). Also, I am not currently using a band filer. Would that be necessary with this kind of setup? Am I better off just finding a different location on the roof to place the antenna?
Thanks in advance!

So i just checked the amplifier I have. It’s an EDA 2100 and support only goes up to 1000MHZ so I don’t think this will work.

hello nick,

i had nearly the same situation here at my house - so i’ll try to give you an answer …

don’t know what cabling you use over there in the us for sat dishes. here in germany we have 75ohm - and that is not what is used for ads-b antennas (50ohm). 130feet with the wrong impedance probably gives bad results.

the best results can be achieved with the shortest possible antenna-cable. that’s why i mounted my raspi in the attic and connect via usb-wifi dongle to my network in the upper flat. maybe this could be an option for you too.

about the fa filter i don’t have practical experience at the moment.

kind regards
tom

p.s. here is a picture of my setup up today - will mount the antenna next week on the roof
https://dl.dropboxusercontent.com/u/39745369/raspi_adsb_01.jpg

Thanks for the reply Tom! The cable impedance is 75ohm here also.
That being said, I’m probably going to do exactly what you have suggested (shortest possible length for antenna cable). I bought an outdoor sprinkler system timer box to mount everything into and use a PoE Injector Kit I picked up to supply power (as there is no AC up there).

About maximum 25 feet of RG6.

…If i had to estimate the cable length, I would say it is (at max) 130 feet. Will that length destroy the usable signal? …

Yes, attenuation of 130 ft of RG6 will sure make signal very week.

…If so, would an amplifier work to resolve this problem?

Yes, sure, to a great extent.

I have an extra cable amplifier that is not longer being used here (I will have to verify the frequency support).

Ampliffiers with upper frequency 1000 Mhz normally work ok even at 1090 Mhz. However some TV amplifiers may not work with 1090 Mhz, particularly those with lower frequency very low like your amplifier’s 54 Mhz. Your amplifier also has a band 2 to 52 Mhz. Most likely it wont work with 1090 Mhz, but no harm in trying. You can know the suitability only by trying it.

…Also, I am not currently using a band filer. Would that be necessary with this kind of setup?..

Filter is required normally where strong interference sources are there, like a cell phone tower nearby.

…Am I better off just finding a different location on the roof to place the antenna?..

Only if:
(1) new location results in substantial reduction in cable length.
(2) new location gives lesser obstructed view of horizon.

perfect - this will give the best possible results - and all the hassle with these coax-cabling is left behind :slight_smile:

have a good one
tom

…Am I better off just finding a different location on the roof to place the antenna?..

Only if:
(1) new location results in substantial reduction in cable length.
(2) new location gives lesser obstructed view of horizon.

So the antenna location is the highest point on the house and is the same regardless of the Coax cable run. I was just trying to avoid needing to run a CAT5 cable over there as it’s a somewhat difficult place to get to… not impossible, just difficult. I’m going to tackle that on Sunday.

There are no cell phone or other antennas nearby. At least none that I’m aware of (my Verizon and AT&T cell phone get crappy service here).

Even inside, right now (for testing), I am getting responses from aircraft in the 60-120 mile range. Site 13493.

Here is my system and coverage map.

My entire installation is strictly indoor, as I live in an apartment with no balconies. The antenna is located near a wall sized glass window, at a height of about 60 feet above road level.

My Antenna (Cantenna)

My Coverage Map (My System shown in top left corner of the map)

1 nautical mile = 1.85 kilometers
1 nautical mile = 1.15 miles

abcd567,

We are helping each other with overlapping… :smiley:

I’m in Detroit so overlapping as well! How do I get those coverage rings on my map? I’m using the PiAware RPi Image from FA with no modifications.

I am running Dump1090-Mutability. The rings are in that package. There are a few posts on here about installing that. But you will need to install Raspbian on a SD card. Might be a good idea to try that on another SD card, so you can always fall back to the SD card image that works if you run into problems.

That I can do. I have a few extra RPi2’s so I’ll just try it on one of those. What version of mutability are you using? I see 1.15 in this thread.

This tread might be a good start.

ads-b-flight-tracking-f21/what-is-easiest-way-to-install-dump1090-mutability-t35431.html


?HOW TO GET ALTERNATING BLUE/RED CIRCLES IN DUMP1090-MUTABILITY

?HOW TO GET ALTERNATING BLUE/RED CIRCLES IN DUMP1090 IN PIAWARE

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Thank you everyone for the replies!

hi nick,

just one more thing. yesterday when reading your re-post i overlooked that you wrote ‘power over ethernet’.
as far as i know - please correct anybody who knows better - you need a poe splitter on the raspberry side also.
so - while the injector you have brings power to the ethernet cable - the splitter does the opposite to a micro usb cable or the raspi internal connector.

regards
tom

Best thing to do is just try it with the 130 ft run. If it works good, you are good to go.
Your flight aware antenna has a gain in the 5-6 dbw range. The 130 foot cable is going to have a loss of about 6-7 dbw - So, you will end up with an antenna physically located for good reception but with minimal gain in the system.

Good idea! Taking advantage of high gain Flaghtaware Antenna.
And if it does not work good, add an in line Satellite amplifier + Power Inserter, like these:
NOTE: These are only few examples. I suggest you search Amazon.com & eBay.com to find a heap of choices.

AMPLIFIERS:
NEW PERFECT VISION IN LINE PVLA-30 SATELLITE AMPLIFIER 30DB GAIN 950-2150 MHZ POWER PASSING 8 TO 29 VOLTS

Paladin Tools 9672 In-Line Amplifier

PCT 20 dB In-Line Satellite Amplifier 950-2150 MHZ DC Passing Fixed Slope 20dB
http://thumbs.ebaystatic.com/images/m/m8EEsO_Rh-9iGgSmQOhPWUw/s-l225.jpg

POWER SUPPLIES:
DIRECTV PI21R1-03 Power Inserter, 21V DC

Pico Macom PS10 Power Inserter with Diplexer Supply 15 VDC 15 Volt In-Line

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If you are putting the Pi by the antenna - then it’s probably worth looking on ebay.com for ‘low noise RF amplifier’ - you’l find one designed for 50ohms with SMA connectors for 10-15 dollars, and it needs 3.3 -5v supply … which is easy to collect from the raspberry Pi GPIO (just google raspberry pi pinouts).

By the way that connector has 0.1inch pin spacing … just like the cables in old PC’s for IDE disk cables, speaker connectors etc (check the junk box).

No need to do power up the wire to a satellite amp.