Graphs


#1

Trying to understand what I am looking at and if there are issues I need to correct. I have two RPi’s running Piaware with Mutability v1.15. The antennas are both 12 segment coco built with RG6 coaxial cable. The west site cable is 60 feet long with two f connections in the line including the connection to the SDR dongle. The east site cable is 35 feet long with the only f connection being to the SDR. The two sites are roughly 100 miles apart with the east site receiving more messages.

Looking at the graphs I notice a difference. I see the West Site has many more tracks with single tracks than the East Site.

West Site

East Site

What do you think? Could I have an antenna problem that is missing data? Does the single track message indicate I am missing flights?

Thank you!


#2

Single-message tracks are usually noise, so the top graph has more noise overall for some reason. (More gain, worse shielding, external interference, etc)

Given that co-co antennas are notoriously fiddly to get right, especially with as many as 12 segments, I’d be tempted to say it’s just differences in the antennas. The feed line differences could do it too.


#3

I see. I will look at the antenna next time I am out there. Thank you!


#4

I’d say you need a little amplification on the long cable.
Just a little bit will do it.


#5

If convenient, try swapping the antennas and retest.
Just a thought from someone who could break a brick by throwing it at window :wink: