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I finished construction of high-band QMX rev2 (2024), 9V version.? Checked and rechecked all my soldering under magnification and probed for shorts with an ohmmeter.? Time to apply power and do the smoke test.

I set my bench supply to 6.8V with a very low current limit.? I'm passing the power through a ViFly ShortSaver 2 (per recommendation on this forum), but since the current limit on the power supply is set well below 1A, I don't expect the ShortSaver to actually function as a circuit breaker right now.? When I turned the bench supply and the ShortSaver on, the meters on the supply read 6.8V and 40mA.? I stopped there, and did not press the rotary encoder to power up the radio.? Before I do, I want to know if things are OK so far (after all I've read on this forum, I really want to be careful not to blow the QMX up.)? Should there be a quiescent power-off current draw?

Thanks,
Eric

On Fri, Feb 23, 2024 at 05:54 PM, Eric W. Hansen wrote:

ViFly ShortSaver 2

Which current if you remove the power connector from the QMX? How much power consumption by the ViFly ShortSaver 2?

73, Ludwig

On Fri, Feb 23, 2024 at 05:54 PM, Eric W. Hansen wrote:

I set my bench supply to 6.8V with a very low current limit.

Be aware you need around 160 mA to start the QMX.

Thanks, Ludwig, good question.? The ViFly, with no load connected, registers 40mA on my bench supply's meter, same as with the QMX connected.? This implies that the QMX isn't drawing anything, so I can now increase the current limit on the supply and push the button on the rotary encoder.

Eric

On Fri, Feb 23, 2024 at 08:49 PM, Eric W. Hansen wrote:

and push the button on the rotary encoder

Hi Eric,
I did this yesterday at my 2nd QMX (20 m - 10 m) and it worked.

Wish you success.

73 Ludwig

Despite the lack of a backlight, my computer recognized the QMX, so I installed the firmware and it worked (even got a backlit display).? Maybe the processor thought I was in firmware update mode rather than initial setup mode?

Setup and testing will continue tomorrow.

Thanks again, Ludwig,
Eric

On Sat, Feb 24, 2024 at 01:27 AM, Eric W. Hansen wrote:

Despite the lack of a backlight, my computer recognized the QMX, so I installed the firmware and it worked (even got a backlit display).? Maybe the processor thought I was in firmware update mode rather than initial setup mode?

Setup and testing will continue tomorrow.

This is the expected behaviour.? When you very first power up a QMX it looks completely dead - no display or anything and is in a state expecting to be connected to a PC and have the firmware loaded in.? Once the firmware is in it then springs into life :)

Good luck with the rest of the testing - they are great radios.