Bought one of these antennas:
and installed it using a metal chassis from an old DVD player and the results were.....DISAPPOINTING. My home made ground plane (spider) antenna works much much better.
The original dump1090 was setup to be its own web server, so you would connect to it on port 8080. Dump1090-mutability is setup to NOT be a web server, and delegates that task to lighttpd. The default setup is to run lighttpd on port 80.
I think I may have found the perfect way to keep RF out of my RTL dongle:
If you look at the graphs (and translate the German) it doesn't work very well as a bandpass filter.
I added one of these (bought used off ebay) to my setup and it made a huge difference:
same thing in SMA size...
You're attempting to make a notch filter, not a bandpass filter. The signal you are filtering is already on the wire, captured by the main antenna. The stub is not an antenna. So I would measure from the T-intersection to the end. You are trying to make a device where a signal and it's...
Using the BNC connector as a reference, the antenna looks too short for 1090Mhz. But this exact antenna is widely sold for aircraft transponders so it must be correct.
Here's more information about the antenna:
There are two things you need to worry about while using the long USB:
1. Voltage drop. Make sure you have a really good USB supply feeding it.
2. RF - the long USB cable acts like an antenna. Put some ferrites right next to the receiver on the USB cable.
I've got this antenna on order from Bulgaria:
Edit: This would have been my first choice, but it's 3 times as much: