I bought this 16.5 cm antenna with 3m cable and SMA as a starter with the FlightAware Pro Plus stick as I wasn´t sure where I´d exactly mount things. (currently right under the roof-top)
NooElec quoting the same 3dBi gain for their dedicated 1090MHz 8.5cm mini antenna I took the plunge, cuz I thought it must be better when I use it same position without a cable / directly on the receiver.
Theory.
Reality: When I get a dozen planes and up to 400km coverage with the prior antenna, I don´t get a single one with the NooElec. <aarrrggghhh>
Isn’t the tip mounted with a screw on the socket? That’s what normally would be the case. You can remove the tip and replace it with a hard wire in the correct length.
That’s what i did without cutting anything on the original
I did not purchase the NooElec one. Mine was unbranded one from ebay.
I cut the plastic by a small hacksaw. The NooElec one may be open-able by twisting.
I have tried 2 similar to yours. See photo below. The left one is 300mm long (including base) and middle one 200mm long (including base) like yours.
Both performed miserably.
I have removed the bases and using the bases for my DIY antennas (Click here).
Thanks for your detailed reply!
Re NooElec disassembly: Did some twisting and bending. The top will need some (or more <g>) force to come off.
Re coiled whips: So the whips are connected to signal and the base to ground / shield!? No coils or sth. in the base?
Re measurements: Costly, yeah, what I heard in Andreas Spiess’ YouTube videos.
Is it worth it to try some tweaking? Saw some antenna-related settings in the SW, but can´t find them any more.
Re FA vs. AirNav: Planning to stick the AirNav onto some tube to raise it above the roof-top. (ca. 50 cm)
How much above the roof should the antenna-base be and does the tube material matter?
And: Would you shorten cables? Need a meter or two (depending on model and mounting).
The coiled whip has 3m, the AirNav seemingly 10m.
@gue22 - Definitely worth tweaking. There are some threads around here about those coiled wire antennas. People shorten them up to a specific length and stick the magnet mount on round metal lids to cookie tins or similar. The metal lid gives the antenna a ground plane and shortening up brings it better in tune for 1090. Not sure what to search for but you can optimize those wire coil antennas. When properly tuned, an antenna can help pull in signals of interest while “rejecting” noise.
Lots upgrade to different antennas like a discone or the FLightAware stick. I use the 26” FlightAware stick and it made a huge difference to my range and numbers of aircraft tracked. It was just a connect up and go kind of thing but i did need to also get coax and a proper adapter connector.
If mounting antennas outside, you may also want to look into lightning protection.
Those antenna settings you found - maybe to enable LNA power on the antenna cable? I think the Nooelec’s have that capability.
On shortening cables, it depends. There is per-foot/meter loss in coax and you can improve signal strength, but if the cable isn’t too much longer than needed, it gives you flexibility while sorting out your station. Hand wavy but hard to answer without knowing your coax and the length you are planning to cut.
Regarding the FlightAware vs AirNav antenna… I have both. It seems like the AirNav one are getting me more planes. Note: They are still indoor, placed 20 cm apart, and a lot of trees, buildings, etc. are in the way at the moment. The setup is the same for both. Antenna > Uputronics LNA > AirNav green stick > Pi 4B.
The persistence mode was enabled at the same time this morning to see the difference.
Thanks for the schematic! This simplicity opens up a lot of options. Got the Mag Mount thread already open, but didn´t get around to it.
Possibly stupid q: If I don´t use the base I´d use a ground plane or where do I hook the shield?
I think I remember some VERBALLY grounded radio with a flat antenna (300 Ohms?) cable from my youth (for AM radio?). <grin>
Nothing else than the mains ground??
You´re also confusing me with your Quick Spider article. The RG6 apparently is 75 Ohms and not 50, like the RG174.
And is there a reason that the stuck-in radial part is 21 mm?
Guess 150 NM and all kinds of obstacles is some accomplishment in Denmark. What´s your elevation?
I remember my flight instructor wanting me to find the highest “mountain” in Florida, called Mount Trashmore, a cultivated ex-dump, 150 feet “HIGH”. <rofl>
I´m on 300 m with unobstructed view of Alps peaks.
