RTL-SDR Blog Rtl Sdr Blog Wideband Low Noise Amplifier Bias Tee Powered

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.

Strong enough for my project.Case can be taken off and you can hardwire 5V to the board as bias tee does not work for tx or rx on some of my SDRs. Very pleased. Thank you seller.

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

I am completely new to SDR and bought this Low Noise Amplifier (LNR) to try to improve reception, and it really works, giving a huge signal boost. I am using RTL-SDR V3, SDR# with a Moonraker Skyscan Desktop Scanner Antenna. With the addition of this LNA I can now hear stuff I could not hear at all before. Two of the screen shots show the signal in SDR# with the LNR turned off, and on. The boost is so great I had to reduce the range after turning the LNR on to illustrate this.Tip 1: If using RTL-SDR V3, the RTL-SDR V3 must not be in use by SDR# when running the bias_tee_on.bat. Stop SDR# from running or close SDR# before running the .bat files.Tip 2: when powered by Bias Tee Power, the LNR has a tiny green LED at the base of the out jack, as shown in the photo. It turns on when the Bias Tee Power is on. It is very hard to see in daylight. The LED is off when the Bias Tee Power is off.Tip 3: getting bias T power to work in RTL-SDR V3 is is tricky (in WIndows 10). The RTL-SDR V3 dongle drivers have to be correctly installed using zadig.exe. In my case, I had to update the drivers on "RTL2832UHIDIR" , not the "Bulk-In, Interface (Interface 0)". See screen shot.Tip 4: Based on my observations, I think that if the SNR is not powered it diminishes the signal from the antenna. So you might want to remove it from the signal path when not in use.

Works as advertised, very good.