开云体育

While I await delivery of my factory-built QMX (~110 on the wait list) I am wondering what the max current consumption might be? I've got a 10,000 mAh? 5 volt USB "brick", and I'm considering using a 9 volt upconverter to power the rig.

Thoughts?

Rich, KY6O

Hi Rich,

I recently completed a QMX and have a USB powerbank so I thought I would give it a try.? The USB powerbank? I have is a PD type rated at 10,000 mAh 18W.? I have a PD "dongle" connected to it so that I can select an output of 9 or 12Volts.
So, with the dongle set to 9V, I measured 9.14V output.
Running the QMX from this, I got the following transmit outputs.

80m 3.0Watts
40m 3.25Watts
30m 4.0Watts
20m 3.5Watts

Current draw was between 0.8 Amp and 1.2 Amp.? The PD powerbank is rated at 9V 2 Amp output.
So it ran the QMX comfortably and a quick receive check didn't show any significant interference from the powerbank or dongle.

Cheers,?
Glenn VK3YY.

Mine varies slightly from band to band but the highest I've seen on TX is about 1.3A from a lab supply set at 9V.

Jonathan KN6LFB

That’s my plan too. Got the QMX but upconverter is on the slow boat from China… PD seems risky. Another post about the PD negotiation and starting on 5V then a fast increase kills the QMX. Should be OK if plug the QMX in last. Any way gonna test the upconverter cable too first before use.

/Daniel, SA7DAI

On Sat, Aug 26, 2023 at 08:15 PM, Glenn S wrote:

I have a PD "dongle" connected to it so that I can select an output of 9 or 12Volts.

It would be wise to connect the dongle and set (and confirm) its voltage prior to connecting the radio than to do the reverse and possibly subject the radio to voltage gyrations while the dongle output settles.
I use one of those inline USB voltage/current meters to check mine and see what the power bank voltage looks like under load.? I will need to measure how much resistance it uses for its current measurement someday but the voltage drop seems minimal....
73, Don N2VGU