Tagged: LNA

Radio Astronomy with a 0.2dB Noise Figure LNA

Over on our Facebook page member Александр has let us know about a Russian amateur astronomer, Alex who has been using the RTL-SDR for radio astronomy. Alex uses an Elonics E4000 RTL-SDR combined with a 3.7m mesh parabola dish with 1420 MHz waveguide.

At the center of his system is an LNA with 40dB gain and a very low noise figure of 0.2dB. This LNA appears to be based on G4DDK’s VLNA, but modified to work with the 1420 MHz frequency used for radio astronomy. It seems the LNA can be ordered for 140 USD from the above link.

Note: The above Russian links are machine translated with Google to English.

0.2dB Noise Figure Low Noise Amplifier
0.2dB Noise Figure Low Noise Amplifier
Radio Astronomy Results
Radio Astronomy Results

ADS-B Active PCB Antenna for the RTL-SDR

This ADS-B antenna by amateur radio hobbyist F5ANN combines a 30dB LNA preamplifier, bandpass filter and antenna tuned for 1090MHz together on a single PCB board. The LNA preamplifier helps boost weak signals, whilst the bandpass filter helps to remove interference from others signals such as GSM. The novel thing about this antenna is that everything is neatly packaged into a single PCB board, which makes this antenna very compact, and yet have high performance.

F5ANN uses his combined antenna together with an RTL-SDR dongle and the RTL 1090 ADS-B decoding software with PlanePlotter, and was able to receive 194 simultaneous aircraft signals with a message rate of 556 messages a second at distances of up to 250 nm.

Active PCB Antenna
Active PCB Antenna

LNA4All Low Noise Amplifier Review

Over on the SDR for Mariners blog, author Akos has reviewed the LNA4All low noise amplifier. The LNA4All is a 25 euro amplifier designed to improve the performance of the RTL-SDR.

His results show that the LNA works very well. Akos tested the LNA4ALL on multiple frequencies and applications including commercial radio, airband, NOAA weather satellites, AIS and ADSB. As an example of the improvement, his ADSB reception was improved from 83km to 94km. In his review Akos also shows how to provide power to the LNA, and puts the LNA through some simple stress tests.

LNA4ALL Airband Performance

LNA For All – Wideband Low Noise Amplifier

Amateur radio enthusiast and blogger  has released a new wideband low noise amplifier (LNA) circuit that would work well with the rtl-sdr. It amplifies from 28MHz to 2500MHz with a 1dB noise figure. Check it out on his page here. At 20 Euros plus 5 Euros worldwide shipping for a fully assembled LNA, it is quite a good deal.

This small gadget can lower and improve you DVB-T SDR stick noise figure and improve the sensitivity. Adding the LNA in front the front end of your receiver can open another dimension in your reception. Receiving HAM radio satellites should not be a problem even with the small setup and portable antennas.

LNA For All