Which grade of Coax to use


I am planning to get the FlightAware Outdoor Antenna installed on the roof of my 4 story house. I measured the wiring path and it added up to around 43ft. Can some coax expert :smiley: tell me which grade of a coax I should use?



Try this: showmecables.com/product/ccc-127067.aspx

Cost would be around $70 including tax and shipping.

The Times Microwave Brand would be about $50 more.


Caveat. I’m no coax cable expert.

By far. :slight_smile:



Best would be <2dB attenuation:

LMR-400, 50’ with N connectors $56.50 with free shipping tinyurl.com/hp54qvn

N female to SMA male 6" jumper $6.50 with free shipping tinyurl.com/jet4pcs (depends on your receiver, assuming a FA Pro or something with SMA here)


LMR-400 with N to SMA should be easy to find on the net.


Here’s a custom built cable using LMR-400 “Times Microwave” brand.


Supposedly, top of the line.


It is easy to find. What is not so easy is wrestling around with PE jacketed RG-8 sized coax directly into a tiny dongle or feeder. Much easier to manage the short flexible jumper on the receive end. Also, if you desire to put on an inline lightning surge protector, the N connector style gas discharge arrestors are more common and considerably cheaper than the SMA ones. (there are lots of RP-SMA arrestors, but then you get into the whole RP to standard changeovers, etc. and the additional costs and losses therof).

With LMR-400, I like to bring the end into the shack, connect it to a well anchored and grounded lightning arrestor, then use a flexible jumper to the radio.


Why not re-think your approach?
Put the antenna on a short length of RG6 coax feeding the receiver located inside in your attic (or the highest room in the building with mains power).
Then use ‘home plug’ ethernet over mains adapters.
tp-link.us/products/details/ … 10KIT.html

This way, coax losses are minimal, connectors are simple and easily achieved at home with nothing much more than a sharp blade.

I’m running exactly as above and my coax is around 5 metres/yards long.




Thank you all for your support.

And Devonian,
Yes That would be handy too. I will reconsider a better way to route this.

Thank you.



Please don’t use homeplugs, they are absolutely awful for noise emissions and they aren’t particularly good network devices either - While they may not affect your reception on 1090MHz, anyone trying to listen to HF or shortwave will be deluged with wideband noise. The worst examples produce noise right up to 200MHz or above.

Be considerate to fellow radio hobbyists! Get a decent wifi router instead, it will probably be faster and uses spectrum allocated for it.


I have a good Tri-Band Asus router. My Flight Feeder is a FlightFeeder Orange. What USB Wifi dongle do you recommend and how do I setup Wifi on the flight feeder? I assume I have to use the HDMI output and access the OS?


I don’t know if the flight feeder hardware supports wifi dongles directly, so you might be able to set it up that way. You can use a wifi-ethernet bridge which will allow ethernet only devices to connect via wifi, and they don’t require any change in configuration to the device itself. They still think they are connected to a wired network. There are lots of different types available of varying cost, but bandwidth demands aren’t that big for ads-b. Alternatively if you feel like tinkering, an old router with custom firmware like dd-wrt can be used as a bridge.


The FlightFeeder Orange does do wifi, it’s just not documented yet. You can configure it via the touchscreen in theory. You don’t need a wifi dongle, the Oranges have a Pi 3 internally which has wifi built in.

edit: looks like the touchscreen support for configuring wifi didn’t make it into 7.1.
An alternative is to provide the wifi config on a USB flash drive (you may need to hunt for a drive that will fit the FF USB port as it is cramped). Create a file at the root of the drive named “flightfeeder-config.txt” containing just these lines:

wireless-network yes
wireless-ssid your-ssid-here
wireless-password your-password-here

… plug it into the FF and reboot or powercycle the FF. You need to leave the USB drive plugged in as this configuration does not permanently change the stored config.


Cable Attenuation for 50 ft
LMR400 2.2 dB
RG6 4.9 dB
Difference in attenuation = 4.9 - 2.2 =2.7 dB

So the advantage of using best quality & costly LMR400 over using standard quality & low priced RG6 is 2.7 dB. Adding a masthead amplifier can give you a gain which is 7 times this loss

If you use RG6 50 feet, still the losses can be easily covered by FA antenna gain (> 5 dBi) and receiver front-end pre-amplifier gain. Why to break head for something trival? If you want to cover for 4.9 dB attenuation of RG6, use masthead amplifier, these have gain far in excess of 4.9 dB coax attenuation.

Coax attenution is important in transmitting situstion, where watts, or hundreds of watts are involved, and recovering 3 dB loss requires a trnsmitter with double power output. Recovery of 6 dB attenuation requres increasing transmitter power 4 folds. The cost difference is substantial.


Ok, I give… What is a PiAware Orange?


Flight Feeder Orange, I believe. The latest version of a flight feeder by the looks of things.
RPI3 + Mode S Beast + a GPS unit +???


Amen. My HF noise floor has crept up steadily as more and more cruddy cheap power supplies and cable modems make their way into the neighborhood. IMO, the Homeplugs are an abomination. I wonder how users of such would feel if neighborhood hams started using our 2.4GHz privileges at full power of 1500 watts? Totally legal. Cheap WiFi chipsets would be rendered useless within blocks.


My system:
Distance from ISP’s router to antenna = 45 feet
Antenna >> 15 ft RG6 coax >> Filter+ProStick+RPi>>15 ft network cable >> 5-port desktop Switch, speed 10/100/1000 >> 15 ft network cable to ISP’s router.

Working trouble free since last 1.5 years (till last month with generic dvb-t dongle, prostick since last month).
See my stats flightaware.com/adsb/stats/user/ … stats-6396




The FlightFeeder Orange is an RPi3 with a touchscreen and Pro Stick integrated in an orange plastic case (plus external filter). We’re also shipping a Mode S beast based FlightFeeder.


The distance between my receiver (Filter+ProStick+RPi) and ISP router is 30 ft.

I have a spare 50 ft length of CAT6 E network cable. I decided to try this 50 ft length to connect the receiver directly with ISP router, and it worked perfectly well.

Morale of the story: Place the receiver at a location which will minimize coax length, and run CAT6 network cable to your router. Even 50 ft length of CAT6 E has worked perfectly well for me in today’s experiment.

Don’t think that 50 ft length of network cable has resulted in very few planes.
This experiment was conducted at 2:20 am in night, the minimum traffic period in Toronto