flightaware antenne question


#1

silly question…
what impedance is the antenne?
50 or 75 ohm’s ??
personaly i think is 75, bcouse all dongle are 75 ohm (ex airspy, thats 50)
i ask it becouse i dont want te use the wrong cable when i order the antenna soon.


#2

The Two main FA Antennas are 50 Ohm.
There have been a number of posts on the 50/75Ohm mismatch. It cause a 0.1db power loss.
The FA filter is 50 Ohms too.
The coax impedance is not so important. Using quality coax is much more important as the losses at 1.09Ghz can be significant.

One big issue is the N connector. There are two types, 50 and 75 Ohm. The 75 Ohm version has a smaller pin and doesn’t contact the antenna correctly.

From Wikipedia
Picture showing the similarity between 50 Ω (bottom) and 75 Ω (top) Type N connectors

Also, be careful with SMA and RP-SMA connectors.


#3

aah, ok, good to know…