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I received my QMX+ unit preassembled a few days ago. I just want to use it for CW, be able to hear the sidetone, transmit, receive, use the automated messaging to call CQ.?

So far I am not getting any sidetone, no transmit that I can detect, my paddle doesn't seem to respond (I'm set to Iambic A). Power is a 12v Bienno, voltage protection is set to 13v. My EFHW shows 1.0 to 1.2 SWR when tested with the RigExpert.?

Is there a list somewhere that tells "here are the settings you need, to make this thing actually work for CW" ? There are soooo many menu items and I must be doing something terribly wrong.?

Thank you all. 73 KD8ZM?

When this happened to me, it was because I had forgotten to put it in CW mode. It was in DIGI mode!

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Ellis

GM4GZW

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If you are using a fully charged bioenno "12V" lifepo battery,? you are likely putting in well over 13V to your QMX+, and your voltage protection is disabling your transmit, which also disables the sidetone.

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Turn on the QMX+ battery voltage display by going into the 'Display/controls' menu, selecting 'Battery display', then enable it in voltage mode,? and set 'Batt. full' to 12,000 which I think is the default.? Exit the menu and you should see the measured input voltage in the upper right corner of the display.? The dots under the number represent additional 10ths of a volt.? If the number is flashing, your voltage protect has triggered and is inhibiting tx.

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You don't want to run your QMX+ at over about 12V.? A couple of simple silicon diodes in series will probably reduce your bioenno output to a safe voltage.?

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Stan KC7XE?

Stan, turns out it was the voltage protection. So, thank you. I sure wish the voltage readout on the radio had one more digit to show voltage to tenths of a voltage, as other QRP rigs do.?

I've heard others recommend two silicon diodes. Is there an advantage to using those, versus a cheap little voltage regulator module? Do the diodes consume power by converting it into heat, as a resistor does??

I might use 7 rechargeable lithium batteries, as a possible 10.5v solution, to see if that works. Any thoughts on that?

Thanks again!

On Tue, Apr 1, 2025 at 03:01 PM, Braden Glett wrote:

I sure wish the voltage readout on the radio had one more digit to show voltage to tenths of a voltage,

Braden, but you may see exactely this. Please read Operating manual section 5.16 Display/controls menu.

And if you are in over voltage protection the displayed value is blinking.

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73 Ludwig

On Tue, Apr 1, 2025 at 09:01 AM, Braden Glett wrote:

Do the diodes consume power by converting it into heat, as a resistor does??

Yes, so don't bury them under layers of tape/insulation or they will overheat!? W is still E x I.

73, Don N2VGU

On Tue, Apr 1, 2025 at 06:01 AM, Braden Glett wrote:

I've heard others recommend two silicon diodes. Is there an advantage to using those, versus a cheap little voltage regulator module?

An advantage of diodes is that they are a simple 'linear' solution, but yes, as others have noted, they will generate heat.? Each diode drops about 0.6V, and during transmit the radio consumes less than 1A, so the power dissipated in each diode is less than 0.6W.? So small 1A silicon diodes will work fine.? If you are doing CW or SSB, they won't heat up much due to the duty cycle of the TX.? With FT8 there will be more heat, until they cool down between cycles.

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I personally don't use diodes, I use a converter or a USB-C PD power-bank and trigger cable.? For your situation with a good bioenno battery (if you like to use that), just get an inexpensive buck/boost converter.? The 3 amp ones made by Drok are good, but there are lots of other brands.? You can just get a small one without the meters (to save cost/space), and wire it into your cable between the rig and the battery.? Set it to 12.0V (measure with a meter before connecting to your radio), and you will be fine.? These won't generate as much heat as the diodes.? But they are switching supplies, so they do generate some switching noise.? In my use, the switching noise has not been enough to affect any operation (can hear a bit on 160m and 80m, but not bad, and ferrites on the power line would reduce it).? And I recommend the buck/boost rather than buck only, because it will keep the radio voltage at 12V regardless of the battery voltage.

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And again, as others have noted, the 10ths of a volt are indeed displayed, as dots under the volt number, one dot per 10th.

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And thank your lucky stars that you had voltage protection enabled, otherwise you would be repairing internal circuitry that burned out due to over-voltage, likely burned-out finals and driver chip and maybe power supply protection diodes.

Stan KC7XE

Thanks again!

Thank you!