Saw this new Plane Finder dongle announced. Was very intrigued by the “Not an SDR device” in bold in the listing details… (New) Plane Finder Radar Stick
So bought one to look inside, and thought plenty of people here would be interested to see inside as well…
Not sure I would agree with “not an SDR” - I guess what they meant is “not an RTL2832U”…but in any case it’s a nice device:
dual LNA (Qorvo TQP3M9036)
dual filter (Tai-Saw TA0691A)
high res ADC (TI ADC10065)
FPGA (Efinix Trion T20F169)
microcontroller (Raspberry Pi RP2040 RP2-B2)
UART to USB (FTDI 2232)
Cheaper than a Mode-S Beast and more than an Airspy Mini which, at first glance, are likely in the same ballpark performance wise. So even though the price is high, it’s not absurdly so.
Now to check performance. Will be interesting to see how it stacks up against an Airspy and Mode-S Beast.
Let me know if you want more pictures or want me to test anything on it and I’ll do my best (can only seem to post one picture but will upload more to GDrive or somewhere else)
RTL2832U requires a software decoder such as dump1090 or readsb. The planefinder stick has a builtin hardware decoder, so it should not require dump1090 or readsb.
“Unlike SDR-based USB tuners, it features silicon-level decoding, eliminating dynamic range issues for superior performance.”
The hardware decoder FPGA (Field Proramable Gate Array)
FPGA’s main advantage in ADS-B is it’s reliable time-stamping of signals, which makes mlat calculations reliable.
The Planefinder do not allow receivers like RTL dongle to participate in their mlat calculation. They allow only those receivers to participate in their mlat calculations which have FPGA. The receiver suppled by Planefinder is FPGA based.
Do you have a source for that statement?
The reason I ask, is that I feed Planefinder from a raspberry pi with RTL based device and I see MLAT aircraft at low level on their app that are obviously being received by myself and others nearby. I am pretty certain though that none of the other nearby feeders are using FPGA based receivers.
Thank for that.
However I think what that thread is saying is that you cannot view MLAT aircraft on the local web interface (which is true) however they do show on the Planefinder app. I suspect they must be using the data from RTL devices in order to display it in their app just not returning it to the local device.
At $271 each, one would hope that there’s a lot more to this device than just better time stamping for mlat. An RTL-SDR V3 costs $40 at Amazon. Hopefully the reception performance for this device is much improved compared to the RTL-SDR device in a straight up comparison.
The ADC used in this dongle is 10 bit and 65 Msample/s. That’s a better hardware dynamic range than an rtl dongle but not as high as an airspy which is 12 bit. It does have far more bandwidth than needed for mode-s decoding and that extra bandwidth can be traded dynamic range by using decimation.
10 bit dynamic range is about 60dB, and if they use 16x decimation that’s equivalent to an increase in dynamic range of 12dB. That improves the overall effective dynamic range to 72dB which is about the same as a 12 bit ADC which makes it similar to an airspy. Of course if the airspy decoder uses decimation internally as well (I have no idea if it does) then that puts it ahead again.
Given that this is RF signal processing we are talking about there’s probably all sorts of nuance to this which means it’s not a direct comparison. It should comfortably outperform an RTL dongle though, especially where strong signals are present.
FPGA processing does allow much better timestamping of decoded packets, but you have to also consider the other advantages. This is pretty much a self contained device. It does all the processing on board, from reception to decoding, and then passes the output over USB.
You can probably run this on a very low powered device since all it would be doing is handling the USB and network. There would be minimal processing so probably even a pi zero would handle it quite easily.
An airspy mini is £125 on its own, then you need an LNA/filter which will cost you upwards of £40 or so, and a raspberry pi and peripherals (pi 4 1GB is about £35, plus £10ish for psu) and you are at the same sort of price point as this dongle.
It looks like a good product and I’ll be interested to see how it performs in practice. One thing that would be essential to me though would be unfettered access to the raw data. I don’t like it when companies use proprietary formats and don’t publish them for things like this. I don’t really see why they couldn’t have that available on release rather than months down the line. That alone would tip the balance in favour of using an airspy if I were starting from scratch.
If they do add open access to the data as promised then that makes it much more attractive.
It does look like an interesting device and it will be fun to see the comparison tests. Thanks for the photos and details
That “Third-party data sharing available in Q4 2025” is also a red flag for me. You don’t want to end up with something like a JetVision Air!Squitter that requires a very expensive commercial software license just to be able to use standard Beast binary with other feeders.
For those with the normal PlaneFinder receiver, is the mlat timestamp 12 MHz like the standard Beast and Radarcape, or 20 MHz like the original Kinetic SBS family?
Be careful comparing this with the AirSpy receivers unless the AirSpy finally supports mode-a/c for things like mode-a/c mlat and the mode-a/c beamfinder modes. I don’t follow the Airspy devices very closely but often see complaints about that lack of support.
sigh Importing it to say Germany makes it even more expensive.
Right now, if you enter a UK address, it is listed at £199.99, tax included, and shipping is free.
If you enter a EU address like Germany, the £199.99 are converted into € 237.95, roughly the current exchange rate + a few Euros. That then is listed as the price without tax.
So there is no deduction of UK VAT, but you still will have to pay 19% VAT on top of that on importing.
Not sure if there a any tariffs on this type of product, but I think not.
The Shipping costs € 23.95, and likely a € 6 service charge is added on top of that by the courier in question.
So, in total, it will costs €313.11 or £268.44, around 35% more.
I think they should zero rate directly exported goods so that you don’t pay VAT twice. Then you would have to pay German VAT on import, but not UK VAT. I think some companies here will be registered for VAT in EU countries so they can collect it at point of sale. It might be worth an email to them to clarify if you are interested in actually purchasing one.
Well, there is IOSS for goods under €150, which makes it easier for vendors to collect VAT on behalf of EU countries.
On a side note, I checked the price of a uputronics pre-amp. It cost £44.39 or €43.95, tax included in both. Given the exchange rate, one would expect something around €51,78, so it goes both ways, I guess
Well, I am tempted, but lets wait till the first results come in.
Nevertheless, my experiences with buying of UK sellers has been extremely positive in the past!
That’s only really useful if you have a well-synchronized time source to feed to the FPGA though. The obvious choice is GPS time but I don’t see a GPS chip on there.
