Comparing the RSP1 and RSP2 on MF Non-Directional Beacon Reception
Over on our new YouTube channel we’ve uploaded a video comparing the SDRplay RSP1 and RSP2 on reception of Non-Directional Beacons at around 350 kHz. Both radios had their gains adjusted for the best possible SNR and reception. They were connected through a splitter to a Wellbrook Magnetic Loop antenna. The Hi-Z port on the RSP2 was used as Port A and Port B don’t have good reception below about 1 MHz.
In all tests the RSP2 appears to have the better SNR, a lower noise floor and thus better audio, though from the spectrum view the RSP1 seems to have a little less spurs.
Subscribe and keep an eye on our new YouTube channel as soon we’ll be uploading more RSP1 vs RSP2 comparisons, Airspy vs RSP2 comparisons and other SDR related videos as well.
While down on the Longwave band, you can also listen for DGPS beacons, between 285 – 315 KHz, exhibiting a warbling tone. Using software like MultiPSK you can decode the information. At night in the winter you’ll hear some farther away than usual, much like DX’ing the NDBs.
I noticed that in RSP1 The LNA is Off. In my experiments and measures, I found that RSP1 has better sensitivity and lower noise floor when LNA is ON. In fact, LNA must be always on! If the signal at the front end is too strong, than you can lower it with external step attenuator. In that case, the SNR will be much better.
Mile Kokotov, Z33T
I did try use the LNA, but it seemed to be overloading on BC AM causing worse SNR, hence it was turned off. But yes maybe an external step attenuator could help.
The same situation is here. When the LNA is ON, I have overloading products especially in the evening (for HF and lower frequencies receiving). Then I put some 5 to 20 dB attenuation,depending of situation, and everything become better. Much better than when LNA is off. The external step attenuator is very cheap and easy to DIY. The benefit of using external attenuator with RSP1 is tremendous for HF and lower frequencies.
You have different gain level between to devices.
Yes the gains are both adjusted for best SNR on each device. The RSP1 and RSP2 have different gain profiles and so the same gain settings on both devices would not be right.