Move one of my antennas to a pole at 40 feet and am seeing tracks near 230nm which I think is about as far as I’m going to get.
did you check on http://www.heywhatsthat.com/ your max geographic range?
It’s a good comparison if you’re close the the max.
Yeah, in some places I get a little more range and in others not as much as what it shows. It’s pretty close to what is displayed.
Then it’s getting harder to optimize it more.
For me the same, even with my indoor antenna. I am close to the max range i can get for my location.
one of the things which will improve by moving the antenna outside without changing elevation is the number of messages.and the number of aircraft at the same time, but nothing on the range
If anyone is interested, all three receivers I’m responsible for are now totally visible online with live view, graphs, timelapse and heatmap. My secondary feeder and the MTG feeder have only been set up today so the timelapse and heatmap are limited but it’s really interesting to see how the receiver in my loft is massively blocked in some directions, the main one to the south west being the chimney breast.
/edit - be aware that the MTG live view, graphs and timelapse are being served from a Pi Zero so they may be sluggish to load.
I’m looking forward to seeing a full days view from the MTG box.
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nice!
seem to be a very busy spot in Europe on your location…
Thank you for sharing !
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I yeah I don’t have a 1/3 of that traffic in my area of the US.
The south-east of the UK is very busy airspace. There’s 6 airports in and around London and several smaller GA airfields, and then you have all the transatlantic traffic overflying on the way to and from continental Europe.
And it is pretty flat, too. No hills or mountains limiting the reception.
Is that on the MTG plot? The aerial is an eBay jobbie so I’ve got no idea how it’s constructed.
On the MTG plot…
That same effect is visible on the plot from the main receiver which uses a different antenna. I’m using the same eBay antenna as the MTG site and I don’t get that pattern. Maybe it’s something to do with the presence of open water nearby - signals reflecting off it could be causing destructive interference? It’s odd that it’s so regular though.
Did you use the RTL-SDR Wideband LNA?
I have tried cavity filter+wideband and Triple Filter LNA (w/o cavity), but results were comparable on a NooElec SmarTee dongle. Cavity is DC short so better to suppress ESD. Forgot to test the Triple behind the cavity filter.
Been planning to upgrade to Airspy Mini + RPi 4, but I’d prefer providing the LNA’s power with 5V directly (like you did) instead of using Bias Tee (injector). Cavity+LNA will be in a weather proof box in the mast and a few meters of coax to the attic where the dongle and RPi will be. Why? It’s easier to keep temperatures and humidity under control in the attic.
Well, at the moment I’m using the 2-stage triple filtered 27dB LNA together with the cavity filter and I believe that’s just a bit better than the 1 stage 18dB wideband LNA (with cavity filter). Please keep in mind that what works well with the Airspy Mini could be a small disaster when used with another receiver. My Airspy Mini without LNA was already marginally outperforming the orange FA-stick so Airspy Mini is the way to go.
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The blue FA stick kills the orange stick. I saw some tests that said 18% better with the blue. I don’t know the exact numbers I got but the blue stick was hands down better. Then I put in a NooElec smart tee and the LNA for even better performance over the blue stick.
I agree but only if you live in North America where the built-in filter does a decent job filtering out the strong gsm-850 signals (highest frequency in use is 893.8 MHz)
Europe is using the gsm-900 band with frequencies up to 960 MHz, the bandwidth of the filter inside the blue stick is too wide to provide enough suppression for these signals so the best choice would be a cavity filter and an orange stick or even better, the Airspy mini with a LNA.
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Why are cavity filters on everyone’s list? They sound “fancy” but they are no better than a ceramic filter. Plus they are heavy and expensive. They are the only option for emitters, but that’s not the case here.
A ceramic filter gives equal or better results. Sure, is not cheap, Uptronics LNA (39 pounds) with the ceramic filter option adds 51 pounds to the price:
Still less than 100 for a triple pole cavity filter.