NooElec Balun One Nine - Tiny Low-Cost 1:9 HF Antenna Balun with Antenna Input Protection for Ham It Up, SDR and Many Other Applications!

Great little item that appears to do exactly what it is supposed to. I have used it to match my long wire antenna to an SDR and all appears fine. Unsure of the technical details of the Balun, so I leave that to better informed individuals to provide... Overall very happy!

This little balun seems to work perfectly OK, and was a stopgap purchase until I can find time to build a much larger Antenna Tuning Unit. Ideal for someone experimenting with SDR dongles.

great i made my own hf antenna and ive had great contacts.very pleased 73

I connected it to a SMA-SMA patch lead to my Ham it Up converter downstairs and wow! The difference! Less QRN - electrical noise, more signals.

Didn’t make anything better at all. Infact I think it was slightly worse when I used to to when I didn’t. Just did not work at all in my setup. Waste of money.

Very good product and surprisingly small for its size. possible mod to add inside of the RSP1A ? It doesn't boost signal but really helps cut interference and less noise as well. Connected to 40 foot of wire running along the top of garden fence with the ground side connected to a ground spike in the ground. NOTE: works even better after the track is cut on the underside of the board that grounds out pin 2 (other reviewers note how to do this mod). only downside is that MW band gets overloaded at night. there are too many signals !

Excellent indoor balun for matching dipole antennae to SDR receiver input (50 ohms). Also capable, with minor mod, of use as an unun for long wire matching. Good value for money. Will need additional weather protection if it’s to be fitted outdoors.

I bought this at the same time as the NooElec Ham It Up. Unfortunately, unlike the Ham It Up which is excellent, the quality of this Balun is rather poor and I would hesitate to recommend it. If you look at the attached photo you can see the issue - the SMA connector has been mounted in such a way that it is badly offset to one side of the board, resulting in the SMA pin being soldered to the outer edge of the microstrip (it should be central), and also resulting in the SMA lower ground tag almost shorting-out to the microstrip line. Both these problems will disturb the field distribution at the SMA launch, potentially giving a poor Return Loss. Whilst looking at the connector issue under a magnifying glass, I also noticed that the flux has not been cleaned off and it is trapping a number of small balls of solder splatter, which are trapped between the microstrip line and the adjacent ground. Not a big issue, easily cleaned, but indicative of a lack of attention to detail in manufacture. This may sound 'picky' but I wanted to highlight that there are opportunities to improve the manufacturing, and that if you purchase this item you should examine your Balun carefully for defects if it is not working as you would expect. Hope this helps someone!

Buena calidad de fabricación, robusta y sencilla de conectar. Cumple su función sobradamente. Como balun para antenas tipo Yagi ya sea comerciales o de fabricación propia, permite adaptarlas a los receptores SDR con facilidad y gracias a su pequeño tamaño se pueden proteger de las inclemencias del tiempo en pequeñas cajas impermeables adosadas a la propia antena.

"Balun" ist das Kunstwort aus "BALanced-UNbalanced" und kennzeichnet Transformationsstufen, welche symmetrische Leitungen (z.B. UKW-Flachbandkabel) auf unsymmetrisch (z.B. RG58-Koaxialkabel) anpassen sollen oder auch den symmetrischen Ausgang einer Loop-Antenne an unsymmetrisches Koax. Wenn man anfängt, einem ursprünglichen Balanced-Signal "Ground", also Erde hinzufügen zu wollen, dann verschiebt man die komplette Philosophie einer symmetrischen Speisung in Richtung Rauschen. Wenn man aber einen Langdraht benutzt, macht das Teil schon Sinn, mit dem Anklemmen einer Erde muss man experimentieren. Bei einem separaten Staberder mag es noch angehen, schliesse ich aber eine Erde aus dem häuslichen Bereich (Metallrohre, wie Wasser oder Heizung) an, dann ziehe ich mir UNWEIGERLICH den häuslichen EMV-Störnebel in den Empfänger und der Rauschflur wird unangenehm. Selber bin ich komplett weg von unsymmetrischen Systemen und benutze nur noch eine 70 cm-Loop für AM von Mittelwelle bis hoch zu 30 MHz, die geht mit einer symmetrischen Leitung (DSL-Rangierdraht) vom Speisepunkt bis direkt an den SDR-Eingang. Damit höre ich in Samao, Fiji und Papua-Neuguinea das Gras wachsen. Tip für alle Langdraht-Fans: Einfach zwei Drähte (max. 8 Meter lang) jeweils an die Balun-Klemmen dran, gerade nach Links und rechts gespannt, evtl. auch im Rechten Winkel je nach Platz, am Ausgang des Balun ein Koax dran und nach evtl. Filtern rein in den SDR-Eingang. Der Empfang ist erdfrei und zehnmal rauschärmer als "irgendwie eine Erde" dazu zu klemmen. An eine Loop kommen allerdings Langdrähte nie ran, weil sie die E-Komponente des elektromagnetischen Feldes empfangen, und damit die EMV-Störungen, die auch meist das E-Feld verseuchen. Eine Loop empfängt nur das H-Feld, und dort ist der Rauschflur extrem gering, weil die Störungen des häuslichen Nebels kaum das H-Feld beeinträchtigen.

Being in the market for a balun for some time now I finally broke down and bought the NooElec Balun 1:9 which filled the bill perfectly! After doing a month of do diligence in the search for the ultimate Balun for RTL-SDR radio reception use. The quality is absolutely first rate in form, function and finish. The best parts on a top quality PCB (nice and thick) which makes for a thoroughly functional & high performance Balun for SDR radio 'reception'. As such, it CANNOT be used on a transmitter as you'd fry it in one hell of a hurry, so don't even try! It's small size belies it's Superior abilities. It even has circuit protection Built-in. Therefore your radio is safe in the event of an ESD-type of ingress into your radio. A nice consideration! Also, it's made in Canada and the USA! The price is just right, and the form factor perfect for the DIY'er who likes simple and quick mini radio related projects to do. This was my first and successful try at making a suitable waterproofing closure for my new 1:9 Balun which was surprisingly easy, using PVC plastic parts that anyone can purchase at the hardware store or builder's supply. And at ONLY $15 US, it was an absolute no-brainer. I know I'm going to be buying one or two more of them for use in different configurations. Yes, you can't go wrong with NooElec as I'm quickly finding out! First Rate & Top Drawer . . .

Small, but useful. Works very well with the only drawback is it uses sma connection. A good buy.

Fonctionne parfaitement bien pour la réception onde courte (HF) associé à une clé RTL 2832U