Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please refer to the product documentation or check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

Flex 6400M current draw vs my other rig.

Ross Slater
Ross Slater Member ✭✭

I have a 6400M and a Icom 7300 using same power supply, tuner and antenna. My question is why does the 6400M draw so much more current then the 7300? Example on 30m FT8 running 60 watts 1:1 SWR (with external tuner) the 6400m runs around 20-22 amps. When I switch over to the 7300 it's runs at 13 amps. Thanks.

Best Answers

  • Erik Carling EI4KF
    Erik Carling EI4KF Member ✭✭✭
    Answer ✓

    My 6400M draws 23 amps at 100 watts. At 60 watts it draws only a little less, around 19 watts. I guess it is just more electronics versus the 7300, like the screen for example. The difference between my 19W and your 22W is probably only PSU meter calibration error.

  • Ross Slater
    Ross Slater Member ✭✭
    Answer ✓

    Thanks Erik

  • Stan VA7NF
    Stan VA7NF Member ✭✭✭
    Answer ✓

    You are making apples and oranges comparison. The flex uses a high current bias to place your signal in the linear portion of the amplifier operation. Your numbers are higher than in my 6700 case - 17-18A at 14V which is around 250W for both keeping the RX running while transmitting. In round figures half that power is final bias and half is your transmitted signal.

    The 7300 is ICOM's low cost entry into the (as they call it) SDR world. I cannot speak to ICOM's cost engineering but am not surprised that the transmit final amp bias is set for a much lower power draw as less bias current requires lower power transistors and lower cost powering circuits; aka cost engineering. I expect flames.


  • Ross Slater
    Ross Slater Member ✭✭

    Thank you I understand now after doing a little more research and some input from other operators.

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.