At the January 17, 2019 club meeting, we did some power consumption testing of a number of the showcased "small HF rigs". Here are the results.
Elecraft KX3, 5 watt power setting, 7.125 MHz SSB voice id into dummy load, 0.2A on RX, 1.5A on TX
Kenwood TS-50, 10 watt power setting, 7.125 MHz SSB voice id into dummy load, 1.0A on RX, 2.5A on TX
Yaesu FT-891, 5 watt power setting, 7.125 MHz SSB voice id into dummy load, 1.1A on RX, 4.7A on TX
Yaesu FT-857D, 5 watt power setting, 7.125 MHz SSB voice id into dummy load, 0.6A on RX, 2.6A on TX
Unfortunately, we'll need to test the FT-817 and Xeigu X5105 later as the external powering cables for these radios were not available at the meeting, however, looking at manufacturers' specs for these radios we can estimate:
Yaesu FT-817 max 450mA on RX, 2A on TX
Xeigu X5105 max 660mA on RX, 2.5A on TX
It would be nice to truly test these radios with the same test parameters and using our same measuring gear at a future meeting or event. The Xeigu, for example, has many features that might be turned off to conserve power on a SOTA activation - the manufacturers' specs are worst-case.
Interesting results none the less. You can definitely see how efficient the KX3 is for DC power consumption - a true mountain-topper. The Kenwood TS-50 is surprisingly good on the TX. The Yaesu FT-891 is a bit more power hungry - might as well transmit at a higher power level (which I will considering the low solar activity period we are in right now). The FT-857D has decent RX consumption for a 100 watt capable rig and decent QRP TX consumption as well - could this be the ultimate all-bands all-modes QRO radio? Bob and I will compare RX performance at our next field use event. The FT-817 and Xeigu X5105 are not quite as efficient as the Elecraft (according to manufacturers' worst-case specs), but we really need to test them with the same test case to truly compare.
Thoughts and FYI,
Mike VE7KPZ