FlightAware Discussions

Building a new receiver, this is going in a prime location - Suggestions for receiver/preamp/filter please

I’m looking to build a new system, one that’s going to be located not too far away from me, in a good, high position with a clear view to the horizon in every direction. I have a commercial colinear and am trying to decide which receiver/preamp/filter combo to buy.

The aim is to use the Uputronics 1090MHz ADS-B Filtered Preamp (ceramic filter version) but I’m undecided on which dongle to use. As I’ll be running an external preamp/filter, is there any point getting the Prostick or Prostick Plus or am I better off with a standard RTL-SDR dongle?

There will be practically no coax involved, the Pi, receiver and filter/amplifier will be mounted at the base of the aerial.

Or are there better suggestions? I’m in the UK so anything suggested needs to be readily available here.

My two current receivers sit in the top ten in the UK and I want this one to outperform them.

Thanks.

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Have you checked out these: https://www.moonraker.eu/airspyrmini-4917

Anyway i would probably get the rtl-sdr blog v3 dongle you linked instead of the prostick plus.

I also like the rtl-sdr blog LNA but i’m not sure it’s available from the UK (you can just get it shipped from Hong Kong).
Have never seen a comparison with the uputronics amp though.

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If you use the std RTL-SDR then you can use it to power the uputronics amp via bias-t.
There is no need t run a USB cable to power the amp. It also has a metal case to reduce noise(received and transmitted).
The FA dongles, as far as I am aware, can’t power an amp using bias-t.

Also, an airspy can also power the amp via bias-t, should you want to upgrade to it later.

@keithma
Hi Keith,
Nice to see you here after a long break.
Welcome back.

I’m doing a similar effort and will direct connecting the FA antenna to the FA Prostick+ plugged directly into a PI B+. No coax - one adapter in a box on the roof. If I have the room (in the enclosure), would the Airspy above plugged into the Uptronics filter-amp out perform the FA Prostick+ ?

Scott

P.S. Inspiration from this link: https://imgur.com/gallery/dpyGo

@abcd567
Thanks - despite hating discourse with a passion, this is the best place for advice.

That’s more or less my current setup (with the FA filter thrown in). I want to improve on it and the availability of the site I mentioned is a great chance to do that with a new build.

If price is not your major consideration, dump :slight_smile: the sticks and get a dedicated receiver such as the Mode-S Beast. Its really chalk and cheese.

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The biggest improvement will be going from no external amp to an external amp.
Checkout this page:
(https://www.rtl-sdr.com/new-product-rtl-sdr-blog-1090-mhz-ads-b-lna/)
and this page:
(http://www.radioforeveryone.com/p/review-rtl-sdrcom-ads-b-filtered-preamp.html)

So either preamp is a win over using even the prostick+
(I wouldn’t recommend using the prostick+ together with a preamp, though it sure is possible and the difference to a rtl-sdr blog v3 dongle should be minor, you will need to run a rather low gain though as all the LNAs in the signal chain really amplify the signal)

Regarding the airspy mini, i couldn’t find a good comparison but it should yield a better reception.
The difference to not using one of the amps will likely be smaller though.

@navzptc Didn’t you test the airspy mini vs rtl-sdr v3 behind a LNA and splitter?

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In my tests using the v3 and mini, I found the v3 to be better than FA/generic ones I had used before but they were no comparison when I started using the mini.

Using my filter/LNA without my splitter I found g -21(mini) and 48/49.6 (v3) to be the best for my set up.

Meh i failed to take proper screenshots of the FA stats when you had both connected with the splitter, you don’t happen to have such screenshots lying around? :slight_smile:
I guess to be fair one would have to use --fix and -f 1 or --no-fix and -f 0 to really compare.
But i guess you are saying the airspy mini is way better huh?

@wiedehopf

No sorry, I got rid of all my info when I completed my testing, but without a doubt the airspy mini is the way to go :grinning:

@wiedehopf
I know this isn’t going to be an exact comparison but while @navzptc was running the v3 dongle the performance of our sites were almost identical. We would frequently swap places for the top spot locally. I am still running exactly the same setup as I was then and you can see how much better the airspy mini is compared to my prostick plus.

Hmm interesting. I would’ve thought v3 with amplifier would be an upgrade vs the prostick plus.
Maybe i’m wrong about that.
Probably also depends on local interference signals and antenna type. The external amplifiers probably handle mobile towers close by better than the prostick plus, as some have reported problems with that.

I have a narrow band cavity filter in front of my prostick plus.
Without it my results drop considerably. The attached shows the performance jump when I added the filter and adjusted gain last May.

I have used multiple dongles, including both of the FA ones.
The one that really shines is the Airspy mini, because of the higher dynamic range of the input DAC.
It needs a preamplifier in front, I am using one with two SAW filters, powered with central wire of coax. Independent T feed, because of the length of the cable, I need to send more than 5V to get 5V at the preamplifier.

Pretty sure those are SAW filters on your amplifier, or are you talking about a different one from the one you once posted a picture of?

Also your FA stats aren’t really much different between the dongles / stations you have.
Not saying that the airspy mini is a bad receiver, it’s just hard to see from your stats if it is better.

Sorry yes, those are SAW, you’re correct.
Ceramics would be better, I have found some for professional use and posted here somewhere a while back.

Strange is that with the Pi and FA dongles I was never able to get the same results like the Flight Feeder (I was like 5-10% lower) , but with the Airspy I got easily above.
Of course is not proportional with the dongle cost. The best return of investment is with a generic dongle, but to squeeze the last drop…
Right now the Flight Feeder is #645 and the Pi with Airspy mini is #416 in global stats.

Which cavity do you have? I am waiting for one made by Sysmocom, it will replace one filter that has similar specs to the FA Filter.

Minicircuits sells this ceramic filter: https://www.minicircuits.com/pdfs/CBP-1034C+.pdf