Goliath vs David?

Well this is just fun. The epic battle of David versus Goliath: a tiny SunSDR2DX and the mighty FLEX6600.

The battlefield: 15m band, WSPR.

A disclaimer: the test conducted below is not a controlled lab test, nor scientific test conducted by an engineer. It is simply a ham test with an objective to compare two receivers under ‘fair and as equal as possible’ circumstances.

The Flex 6600 is run on SmartSDR platform, desktop PC, Intel i7. The SunSDR on a laptop Intel Pentium gold.

Both receivers are connected to the same antenna (vertical) via 50ohm antenna splitter.

Bandwidth: 3KHz. No pre-amp or attenuation.

The only difference was in the WSPR decoding software – Flex was on WSJT-X while Sun was running JTDX.

The WSPR test ran for 30 minutes, in the early afternoon on 15m band where propagations are rather miserable.

There are three things of interest: number of decodes, uniquely decoded callsigns as well as signal to noise ratio of decoded signals.

Quite frankly, I was surprised with the first run.

Overall, both radios were either on pair, or within 1dB on SNR. However, within the 30 minutes time frame, Sun has decoded 3 DX callsigns that Flex hasn’t: BX3AA twice, both times at -29dB as well as ZL3TKI and WH6GVF. Keep in mind that the majority of these WSPR transmitters run 50mW to 1W in power.

Too early to draw a conclusion and announce a winner? Probably. But right now, my money is on SunSDR2DX. To not just hold it’s ground, but to decode more stations is quite a remarkable feat for a radio which costs half of the FLEX6600.

In the next instalment: an overnight test on a crowded 40m band, with decodes fed into online database for direct comparison. Stay tuned!

SunSDR2DX is available, in stock, ready for immediate delivery.