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On Tue, Apr 1, 2025 at 03:43 PM, @Ludwig_DH8WN wrote:

Michael, where did you connect the GND probe of your Meter to the QMX GND?

Could you measure VDD. You may use JP105 to contact VDD.

Could you measure the supply current from the beginning until the QMX stops?

Could you check temperature of IC101? But please take care it could be hot.

• When connecting to GND I used either a GND port on one of the JP nodes, or the bar on the edge of the board
• Measuring through VDD showed the same results as when I measured R105 (which I had previously measured directly, one probe on either side of the resistor)
  • during normal/healthy operation, it showed ~3.3V, and during the frozen state it showed ~4.5V
• I don't have an inline ammeter to measure supply current yet, but I have one arriving either today or tomorrow and can provide those readings at that point
• Temperature of IC101 was cool enough that I could touch it with my fingertip and and it felt about the same as room temperature, so about 17°C / 63°F

That confirms what I thought. It still seems like there is something firmware that could change how this behaves. Was just hoping there was a quick, easy solution. With these here decoding MFSK modes like MSK144 and VARA becomes difficult unless you have a strong signal, and MSK144 is a weak signal mode to begin with.?

Ok real help has arrived! CUL.

Q501???

Nice find.

Reminds me why carefully inspecting the whole board under magnification is so important.?

Thank you!

I would like to purchase an assembled (working) 10 watt linear hf amplifier.

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Thanks,

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AC4OW, Sam

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I have ordered a low pass filer from eBay:

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Assembled 12v 100W 3.5Mhz-30Mhz HF power amplifier low pass filter LPF Kit

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Thanks again!

Also do you have the internal GPS? if so unplug it.

Also is it in a case? If so remove it.?

On Tue, Apr 1, 2025 at 07:54 PM, Michael Shiplet wrote:

However, the measured voltage across R105 went from ~3V (normal operation) to ~4V (frozen)

Michael, where did you connect the GND probe of your Meter to the QMX GND?

3 V ... 3.3 V would be ok. This signal comes direct from a controller I/O-pin and the controller runs from VDD 3.3 V. 4 V is wrong. Maybe VDD is going wrong after a few minutes. This would be dangerous for some IC especially the controller. Could you measure VDD. You may use JP105 to contact VDD. But TAKE CARE not to connect VDD to "+12V". This would destroy some important elements.

Could you measure the supply current from the beginning until the QMX stops?

Could you check temperature of IC101? But please take care it could be hot.

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I would avoid to transmit in the moment.

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73 Ludwig

Also replug the front panel and look at the display connection and while it's out check for a tiny bridge or a whisker that may be in there. That will answer a lot of questions before real assistance comes!

Alright, did the reset, correctly selected the QMX+ version from initial selection, and had about 2 minutes of solid listening time to a QSO on 20m. Thought maybe the reset was going to fix it until I went into the menu to change my keyer setting and it froze on me ?

Will try doing a reset next.

Just tried it - the board gave me enough uptime that I could send a few dahs. It looks like I'm barely putting out any power, but I did see the FWD meter on my ATU bump a little bit. I didn't wait long enough for the radio to freeze out though, so I was at least able to give it a gentle shutdown this time ?

Also is there time to do a reset before the pro analysts see this post? That will give you a headstart! I did notice a little quirky behavior on mine, right after I first powered it up.?

Do you have enough time to transmit into a dummy load on 20?? Does it kick out, immediately??

I have a rev.3 I didn't burn in yet. So let me see if it is working HiHi. You made me think ??

That pulsing signal like CW is what I get too, so I don't think it's external. It doesn't change with tuning, so it seems like something getting injected into the audio.

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73, Dan - W2DLC

Hi George,

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The 12V power source is a 6000mAh Talentcell rechargeable battery. To connect power to the radio, I'm using the included DC plug that I got as part of my kit, which I've joined to one of the barrel connector wires that came with the battery. So the battery's barrel connector connects to the battery, and the QMX+'s barrel connector connects to the QMX+.

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For the 9V, I just used an off-the-shelf 9V battery with a 9V battery-clip-to-2.1mm-x-5.5mm barrel plug.

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73,

Michael

N7WTM

Hi Michael,

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Please describe the power source in detail.?

Including DC plug.?

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73,

George?

K3GK

I finished my QMX+ kit 2 weeks ago.? I built it for 9V, and held my breath as I powered it up for the first time.? ?Everything seems to work fine, and all bands receive and transmit.? I called CQ a few times on CW and saw typical results on the reverse beacon network.? ?I have also worked some FT8 on various bands.? ?So overall, I feel like it is a successful build.? ?That being said, I do have a question about the power output.? ?Running into a dummy load, I get the output as listed below.? ?Are these figures typical on the higher bands, and if not is there anything I can do to help increase the output to where it should be?

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73, Jim (w8ykg)

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160M? 5 Watts
80M ? ?5 Watts
60M ? ?5 Watts
40M ? ?4 Watts
30M ? ?4 Watts
20M ? ?3.5 Watts
17M ? ?3 Watts
15M ? ?3 Watts
12M ? ?3 Watts
10M ? ?2 Watts
6M? ? ? 1 Watt