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Easy progress - change of antennas, amplifiers etc

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  • Easy progress - change of antennas, amplifiers etc

    First post so I hope it's not too much rambling......

    I decided to set up an ADS-B receiver a few weeks back after looking at the flightradar app and thinking "I could add to this" so decided to dig out an old cheap DVB-T stick and plug it into the PC and see what I could get.

    Stage 1: PC + Generic 15 usb DVB-T stick + Stock antenna
    This saw me getting a few hits here and there on Virtual Radar. I was getting 25-40miles range and it was interesting so decided to keep an eye on it and see if I wanted to play more.

    Stage 2 (a week later): PC + Generic 15 usb DVB-T stick + 10 magmount antenna on the garage roof.
    This saw my range double to more like 50-80 miles and I was getting around 200 frames a second. I decided at this point to get another pi and set it up.

    Stage 3 (a week later): Pi + Generic 15 usb DVB-T stick + 10 magmount antenna on the garage roof.
    I started uploaded to FR24 and enjoyed seeing the stats but wondered what else I could do to improve things. I decided to buy a 1090mhz LNA with filter and give this a go. I noticed the range was more like 100-120 miles but I wasn't picking up much locally as it was overloaded. The frames were still down at the 200ish level which wasn't great. I decided to grab a blue pro stick......

    Stage 4 (about a day later) Pi + Blue pro stick + 10 magmount antenna + 35 LNA. (then without LNA)
    This was annoying. I was getting terrible frame rates and very odd range. It'd jump from everything within 30miles to suddenly only stuff over 100 miles. It seemed that the auto gain really wasn't happy with the LNA. I adjusted the gain manually over and over and got nothing useful so I removed the LNA. Wow suddenly frame rates jumped from 100 to about 400 and the range was a nice 150miles or so with local and further afield stuff thrown in.

    Stage 5 (a few days later): Pi + Blue pro stick + 8 element coax-colinear antenna (diy)
    I decided that being a radio amateur I should be able to build a suitable antenna rather than spend 30 or so on a pre made antenna so I looked around for some coax to turn into a co-co. Annoyingly the only solid core coax with foam insulator was LMR400 and I refused to chop that up and turn that into an antenna so off to the hardware shop I popped for some RG6 for 5. A short while later and with the co-co on the ground I noticed the 400 frames were still sitting at 400 whilst on the ground so I quickly set about mounting it to a mast. It's not at its full height yet but it's sitting at 800-1000 frames/sec with a range of over 200 miles now.

    Cheap USB + Stock antenna = 25-40 miles & 50-100 frames per second
    Cheap USB + External Antenna = 50-80 miles & 200 frames per second
    Cheap USB + External Antenna + LNA = 150 miles & 200 frames per second
    Blue Pro stick + External Antenna + LNA = 150 miles & 100 frames per second
    Blue Pro stick + External Antenna = 150 miles & 400-500 frames per second
    Blue Pro Stick + 8 element coco = 230 miles & 800-1000 frames per second

    In short the Blue pro stick is a LOT better than the cheap dvb-t stick for just a few more and with a co-co antenna that takes maybe half an hour to make you can get an impressive jump in signal and frames.

    So far I've not got a decent weeks worth of data to look at because we had a 4 hour powercut on saturday which was annoying!
    Last edited by 2e1hje; 2020-08-18, 13:26.

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