Recently, I did my first head-to-head comparison of ANAN versus RSPduo on HF. I think the results will surprise you.
Let’s get right down to business. My ANAN-7000DLE MKII is a high performance ham transceiver that provides diversity reception with two 16 bit ADC. It costs $2,800. By comparison, my SDRplay RSPduo is a wideband dual-channel SDR costing $280, a 10:1 difference. So, what would you expect head-to-head from ANAN versus RSPduo on HF?
Here’s my regular test case: All India Radio on 11,560 kHz around 1400 UTC. I use this case for two reasons. First, AIR puts in a relatively weak signal that travels a long distance through a difficult path, nearly 13,000 kilometers. Even so, it’s a pretty good performer that’s almost always there every morning. Second, 25 meters is my absolute worst band for RFI from my neighbor’s halogen lights. My interference is typically as strong as most signals on the band.
As you know, my antennas include a 100′ spaced array of two AAA-1C wideband loops along an E-W baseline. These are ideal for wideband diversity reception across most of HF.
My results? Simply put, as you can see above, the RSPduo produced roughly the same results as the more expensive ANAN when compared head-to-head. This is great performance from a low-cost DC-to-daylight receiver with limited front end filtering and 12 bit conversion.
Here is a video demonstration of the comparison which runs around five minutes.
ANAN versus RSPduo on HF – Details
My ANAN did a better job of reducing the noise floor with the diversity setup, mostly from array gain providing a sharper null towards the RFI. With its larger phasing control, the Thetis (PowerSDR) software makes it easier to “steer the beam”. Also, the ANAN uses VITA-49 timestamps in its UDP I/Q stream for great synchronization of data from the two receivers.
The ANAN did a slightly better increase of SNR based on comparing the visual noise level to the signal peak. Overall, the ANAN brought the noise floor down an extra 5 to 10 dB compared to the RSPduo. Also, the signal itself was about 10 dB stronger on the ANAN, but this could be a software calibration artifact.
On the other hand, the recovered audio was better on the RSPduo SDRuno combination. Cleaner, crisper. This blew me away. More tests to come.
Keep in mind this ANAN versus RSPduo on HF comparison is all about using diversity reception to improve signal-to-noise radio in the face of severe RFI from a point source. Your situation could vary based on the nature of your interference.