Review: Nooelec Flamingo FM filter

Broadcast FM signals, such as regular car radio between 88 and 108 Mhz, are a major hindrance to other radio signal reception due to large amount of transmitter power used.
Nooelec's Flamingo FM Bandstop Filter is a solution, costs 15-16 dollars from manufacturer or Amazon USA plus shipping if applicable.



I prefer to compare apples to apples, main competitor is rtl-srd.com's bandstop FM filter, $15, tested earlier, sort of a benchmark in the field.



Tested both for over a month, back and forth, "Dotcom" refers to rtl-sdr.com FM Bandpass Filter, "Nooelec" means Flamingo FM filter for shortness.

Question One: Should you buy one if you have no FM bandpass filter?
Answer One: Yes. Well worth the price.

Q Two: Should you upgrade from a Dotcom filter?
A Two: Don't think so, I wouldn't. Differences aren't earth-shattering.

Q Three: Nooelec or Dotcom better?
A Three: Depends on personal preferences and location. Dotcom is Mike Tyson, Nooelec is Muhammad Ali, completely different approaches. Personally, I favor the Flamingo FM for listening, and Dotcom is invaluable for data or in a scenario when absolute raw power is needed.

Brushed aluminum metal case with SMA connectors, barrel adapter comes in the package to connect to SMA input SDRs, looks fantastic with Nooelec SMArts.
Needless to say, works with any other SMA-based receivers, same connector standard.

Size comparison vs rtl-sdr.com FM bandpass filter:



Flamingo FM is a larger product with unmatched exterior fit and finish; that approach is not new, boys in black have been manufacturing the best presents for the radio lover for ages - SMArt family, new Ham It Up all ooze appeal and quality, just like the fact that Nooelec cannot properly label where the antenna goes and which end shall I connect to receiver. Laser-etched branding (probably, don't have info how the case ends up so delightful) looks good, but the mental and stroking path-finding of where goes what is only fun when the process includes bare skin. (Candles optional, strictly for less RFI).

Remove screws, PCB reveals almost nothing:


Side-by-side versus Dotcom:


I really had to hold back to check under the metal protective screen, wouldn't be surprised if same arrangement presented itself. Or a similar one, it's hard to reinvent a bandstop filter for the same price.
Published information from manufacturers' websites, Nooelec:


rtl-sdr.com:


Different dongles and equipment were used for testing, rtl-sdr.com v.3, Nooelec SMArtee, SMArtXTRtee, and Uputronics Wideband preamp, only swapping filters for screenshots. Both filters pass bias-T:



96.4 FM, less signal is better:



98.8 MHz, going for max SNR ratio on local powerhouse, then swapping filters:


Airband: Dotcom's -3 dB point is 122 MHz, same figure for Nooelec is 115 MHz, and Dotcom suppresses all signals up to that point much more severely - I surmise the above from official lab data, which I rarely read, but my ears told me Nooelec was better, so this is only speculation. Airband starts at 118 MHz. My local airport's (Cork) Tower / Ground / Approach frequencies are all below 122 MHz, and it's not a personal issue, easy to hear (low-level e.g. with a handheld scanner) frequencies for aircraft spotters are all clustered around the 120-mark, you hear permission at St. Maarten from Tower on 118.7 MHz in the bar to finish the cocktail, run to the beach to get blown into the sea.
Local ATIS on 121.85 MHz:


Preamped setup, click on image for full-screen version, Flamingo FM waterfall is somewhat noisier, yet I could hear the actual signal better.
Comparative peek at 137 MHz for our Weather satellite-loving brethren, you really need to view this full-screen:


Definitely less waterfall speckles than without either FM filter. Did more tests on several other frequencies, same story, above 200 Mhz both perform in a similar manner: Nooelec slightly more visible waterfall noise and a tiny bit more audible signal, but at this stage we've had enough boring blue printscreens.
Closing the comparative argument: results above reflect my location, setup, skills, plus many other factors. Since both cost essentially the same, and besides pixel-peeping do exactly the same job, the decision boils down to personal preferences.


ADS-B

Filtered and amplified setup with pro Uputronics 1090 MHz LNA on pro antenna, filters used on two factory SMArts are the only difference, system error maximum 2 % in total position reports received:



Dotcom better. By a small margin, but better.

Would I buy a Flamingo FM?


Straight away. Set aside the beauty of the product, warranty coupled with company support, lack of proper markings, and exquisite craftsmanship, and I'd still buy one as it's affordable and makes a world of difference. rtl-sdr.com's filter is equally good, and might be a better choice depending on personal preferences.
Since I listen to radio most of the time and airband is important to me, I've found great pleasure chasing weak signals with the Flamingo FM.
This one is a keeper.

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