I had both setups. The dark blue filter is slightly decreasing the signal and a bit higher gain is required.
With the Uputronics you need to reduce gain significantly.
For me i needed to go down from 42.1 to 20.7. Otherwise the number of bad messages is way too high, the stick will not find the messages in that noisy stream.
For me the change to Uputronics slightly increased the range by 10-15 NM, but that is maybe also an impact by the better weather. At least it did not decrease
There are rare cases where the Uputronics filter can get overloaded, but you probably would know if you have that kind of noise. So you will likely be better off not using three filters, or even two, e.g. Pro Plus stick (has a filter) → Uputronics LNA+Filter + Dark Blue FA filter. The FA add-on filter probably gives a couple db of insertion loss, so avoid it with the Uputronics if you can. Even then you still will have two filters when you might get the best performance with one! e.g. consider an orange FA Pro stick (no filter) + Uputronics.
For gain settings, the Uputronics adds about 13db of gain over USB and 4.5/5V bias tee from my experience. So as suggested earlier by someone, you need to decrease your gain. e.g. if gain in dump1090-fa was 48, you’d probably want to decrease it to around 33.8 once you add the Uputronics and test different gain settings from there. And many stations get even better performance by lowering gain another 5 to 10db from there.
Before i received my AirSpy, the Uputronics arrived. For two days i was using it in combination with the blue Flight Aware Pro Plus stick.
It’s a clear advantage using it, i was required to reduce gain from 42.1 down to 20.7, otherwise the messages > -3dBFS were way too high.
I have also the dark blue FA filter in one of my drawers. I got it some months ago and it was connected to the FA stick for a couple of weeks.
I needed to increase gain up to 44.5 due to the loss.
Beside that the FA filter did not give me any advantage, so i decided to remove it again. No idea where it would help, maybe in a noisy environment on the neighbor frequencies. For me it did nothing.
I also do not see the why having two filters in use , if both are covering the same frequency. Beside that the FA stick does have a filter for 1090 MHz as well. But i am not that technical expert to get this verified.
So it’s a clear yes for the Uputronics and a no for the dark blue FA filter.
No it’s not clear, you are generalizing which isn’t warranted.
We’re troubleshooting an issue here, for that using the dark blue FA in front of the uputronics makes a lot of sense as the uputronics LNA is set up much like the dark blue FA stick, so the filter is after the LNA which can overload.
The uputronics LNA doesn’t overload as easy as the blue prostick plus but it can.
Conversely the dark blue filter won’t reduce performance much at all, it’s 1.5 dB attenuation which isn’t very much.
The range reduction upon using a correctly powered uputronics 1090 LNA can’t have too many reasons, one of the plausible scenarios is strong interference.
And no not everyone knows there is a mobile phone tower somewhat nearby.
Something else to check: Any RP-SMA connectors on accident (missing center pin, otherwise looks like SMA).
One more thing you would have probably noticed, the uputronics LNA isn’t too tough and the SMA connectors can break off the board and become loose which obviously makes the signal much worse.
Have you tested adding the dark blue filter in front of the uputronics yet?
I currently do have the filter installed, and will change the gain every half hour or so as it is starting to get quite busy up in the sky where I am. I’ll repeat the same time tomorrow without filter, but it does seem to help a fair bit. I have a mobile tower one or two streets away, which was primarily why I purchased a filter a few months ago.
I will run a scan and create a heatmap of any interfering frequencies with and without the filter, which should help determine if it is necessary.
I will also take a close look at all connections, as I am going to be attaching and detaching the filter.
According to the product page, it may have been fixed. But perhaps you refer to something else?
“Since March 2020 we have fitted improved SMA female connectors for antenna input and radio output to address the issue of the SMA barrels coming away.”
I was not replying to the original question, but the statements directly above my posting
For sure it’s not generalizing, it is location and environment based as usual
According to heywhatsthat, may maximum range is about 260 nm. I have added the max. range ring to my map interface.
I live in a large residential area, but my aerial is mounted high up, so houses aren’t blocking the signals. There are a few tall trees here and there (and I mean very tall!). One of them is located in a vacant house, so probably not much I can do about that!
I have this aerial. In the future, I might look at purchasing the official FA one.
Anyway, going back to the Uputronics, I have run a scan without the FA filter and it shows a lot of interference, especially between 800-900mhz. So I will leave the filter installed, as another scan I run shows it is very effective at blocking these signals.
My range, with the Uputronics amp, has no longer decreased, but is staying roughly the same with the current config. (To clarify, that’s with the blue FA filter). I don’t think I will be able to extend my range much, but even if I can squeeze a tiny bit more, I will be satisfied. Otherwise, there would be no point in purchasing a £50 bit of kit!
