RTL-SDR Blog Wideband Low Noise Amplifier Bias Tee Powered

Because there's no instructions, there are some adjustments you need to make for it to do it's best. 1. Connect it as close to the antenna and far away from the dongle as possible. 2. If your software supports it, turn down the LNA in your dongle if it has one. (RTL-SDR V3 has one) I used it for ADS-B decoding and had to switch from dump1090 to rtl1090 and the difference was amazing. dump1090 gave me about 10 planes max with a 50 mile radius, I switched to RTL1090 and I now get 20-30 planes on average with a 200 mile radius. (I live near a major city airport) Using the modded rtlsdr.dll in SDR#, I turned down the LNA to about 25% above 0 and I receive every police band (460MHZ) in the city with incredible clarity. This is an excellent product and just remember, you may have to change some of your settings, but it's well worth it, especially for the price.

Based on the SPF5189Z RF Amplifier IC this device essentially mimics the data sheet specifications according to my tests. I tested it over a voltage range of 3 to 5 volts and it works as advertised, although the gain starts to fall off by a little less than 1 dB from 3 to 3.3 Volts. A great feature of this amplifier is the addition of overvoltage protection to the input. There is a ESD suppressor diode and that is followed by a dual diode in a back to back configuration. That should be plenty of protection. If you are not going to be using this with a Bias T then you can open it up, move a jumper and add some power lads to the provided solder pads. Hooks right up to the V3 or V4 RTL-SDR (Be sure to look for the instructions on how to enable the Receivers Bias-T function before use). Bottom line: I would buy this again. Edit: I added a photo and some RF tests I made. The PCB shot details the circuit and features. The RF Gain shows the measured gain and the Input SWR shows the measured RF Input SWR. Note: On a receiver the input SWR is not all that important and a LNA by definition will have a less than perfect SWR because it is matched for low noise instead of optimizing the SWR, also the inclusion of the input protection will degrade the SWR. All in all the match is fine for all applications that this amplifier is likely to be used in.

Works great! Good build quality

When I received this LNA two of the case screws weren't installed and were rattling around in the anti-static bag. I hope that the quality control of the internal electronics is much better than the assembly. It does work though. I'm using it with my RTL-SDR dongle powered by the bias tee and the noise floor dropped and I can pick out voices much better with weaker signals now. It works as advertised though I do wish that the frequency range covered HF as well. I could have purchased one of the Chinese LNAs that covers HF but they don't come in a nice metal case that matches the dongle, they don't usually support bias tee power without modifications, and my purchase supports RTL-SDR Blog which has a wealth of information about SDR.

There is a night and day difference with this low noise amplifier when used with your software defined radio. The LNA will immediately improve the quality of the signals you receive in the applicable frequency range of the LNA. Its also relatively inexpensive.

My first lna that wasn't already included with the antenna, such as the mla-30+. I hooked this up to a horizontal random wire with 1:9 balun to a rtl-sdr. You do need to download a free sdr# bias tee software to power the lna. By experimentation, I realised all the other sdr software needed to be off before using bias tee on dot bat to power this lna. So, once bias tee on window pops up, activates and pops off, open sdr# and you are good to go. Adjust noise levels as they will increase. And with all this, finally my random wire antenna works as well as my excellent mla-30. Another discovery was , when the rtl-sdr lna is powered, there is a green glow from the interior and can be seen to confirm powered status. I am very glad I added this affordable lna to my collection.

Mine worked. The next one I ordered for my dad arrived DOA. The replacement arrived yesterday and I'll test it this weekend. When working, it does what it's supposed to - using it (turn on the Bias T) brings in signals that were unheard without it. It was the first thing I ordered after getting my RTL-SDR USB stick.

I've had several LNA's, all more costly than this one, and this little gem is the clear winner. I've used it for weeks side-by-side with the others and this one out-performs even ones from Mini-Circuits on my Uniden SDS200 scanner. A preamp won't work miracles, but it certainly helps pull in signals I otherwise could not receive.

I can't easily verify the gain figures but it has helped immensely with reception of NOAA satellites around 137 MHz and 433 MHz data. Works fine using the Biastee in the RTL-SDR blog dongle and is easy to connect in the daisy chain from the aerial.

Can be as much 2x the range, depends on the situation, was able to pick up very weak signal from a long distance

“Received item in good condition, thanks.” works well.

Funktioniert Fabelhaft für Wettersatelliten wie zB. für NOAA 137MHz. Eine Verbesserung um 100%. Wahnsinn, danke !!!

Bought for a longer cable run, allows me to keep the gain control lower on the receiver, no apparent noise increases. All good. Being Bias-Tee powered is a bonus not needing a separate power supply, powered via the antenna cable, make sure your receiver can do that before buying.