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hi
BETTER:
push the tuning knob and hold till it switches to tune mode :)
73 DE muhsin TA1MHS

Good to hear that all works for you. Does your antenna has small coil about 72" from transformer? If so, could you tell me how many turns does it have? Also how high is your transformer above the ground?

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I am trying to setup mine (home brew) but I have problem to get low SWR on 10m band at CW portion of the band.

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Thanks for your help.

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73 de Marek SP9TKW

Fixed.? All I did was add a 220k resistor in parallel to the 22k on the high side of the voltage divider that provides the ADC_5V signal.

The 5V SMPS Status is now OK, Voltage: 5.24V, Duty Max: 78%, Duty Cycle 0%.

The 3.3V SMPS still has Duty Max and Duty Cycle at 51% but that seems OK.

220k may be a bit low, 470 or maybe more would reduce the indicated voltage and might cause the duty cycle to be in range, although having it at zero for both could reduce the switching noise.

Here's the schematic.

On Sun, Nov 17, 2024 at 09:13 PM, Gwen Patton wrote:

I hope you all work this thing out, because I really want one of these for my QMX+. I just have no idea what you're saying.

Hi Gwen,

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My +ABS addition is working very well in my QMX+ after the tweaks we've all been discovering and developing here. I hope to validate Sardar's latest changes to the Companion Board PCB in time to confirm them and shop for some sweet JLCPCB Black Friday PCB promotions for the group's builds. I ordered the minimum 5 test boards tonight.

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If you'd like to do a build and fill all that empty space in your QMX+ case with some useful well-integrated enhancements, please send me an email at my ARRL forwarding address and I'll put you on my list and reply to you. It's the usual ARRL forwarding email address format (<my callsign> AT arrl DOT net). The PCBs will come with pre-programmed PIC and ATmega chips but you'll have to study the thread, particularly back around three weeks ago when the bill of materials (BOM) is discussed and consult Sardar's github documents to buy your other parts. Or join up with others and pool your orders.

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73,

Cal (AD8Q)

Hi Jared,

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I’ve been building this kit for 10m. Some modifications are necessary to obtain good results on that band. But, for 17m, I believe you will obtain reasonably good results by just changing LPF values as you noted. The power output may be about 30W or a little less with 20V supply. If you would like to achieve 40W-50W, it would be necessary to change T1 – T3 cores to #61 material. But, the increase is only a few dB and may not be worth the effort.

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The number of turns you noted for the toroids are the same as the 17m LPF I am using with this kit now.

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The only parts you need to purchase in addition to the kit are 2 pcs 100pF NP0/C0G capacitors. I am not sure whether the parts in your Amazon link are NP0/C0G type, though.

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73, Aki, JO4MTH

On Sun, Nov 17, 2024 at 10:42 PM, Dirk wrote:

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you might have missed it with all the post coming in on this topic.

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I made a stupid mistake during the first measurement and the reset powers the relays off.

Only relay 1, which toggles the capacitances between antenna and transceiver side powers up.

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Thanks, Dirk! Yes--I missed it. That makes sense. If all those relays had been powered-up, my antenna, which features under 3:1 SWR w/o a tuner throughout the entirety of ham HF and even 6m frequencies, would've gone through the roof!

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Did you see the AT-100 EEPROM cells cheat sheet I posted a few posts back? /g/ATU100/attachment/2277/0/EEPROM-Cells%20Content-de_eng.pdf I think some of the codes don't work the way we thought they worked. The codes definitions are in the manual too:

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The one I don't understand is cell 09. Why would one wish to enable a check for maximum SWR, above which auto tuning will not occur? Maybe to preclude tuner and rig thrashing when forgetting to hook up one's antenna or forgetting to rotate the antenna coax switch correctly, resulting in a connection to an open or short to ground?

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73,

Cal (AD8Q)

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Hi,

Fix installation or portable too?

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73

If you have an oscilloscope, you can verify by measuring at the inputs of the PCM1804.? See this post I just made for another op:

Stan KC7XE

Could be either one.? You can measure which one with a signal generator and oscilloscope.? Use a signal generator that can put a sine wave into the antenna jack (around 3mVp-p to 10mVp-p), and an oscilloscope to measure at the inputs of the PCM1804.? For example, put a 14.100MHz 5mV sine wave in, tune your QMX to 14.100MHz in CW mode, and you should measure about a 50mV clean sine wave at each of the 4 differential inputs of the PCM1804 (there is a 10x gain through the op-amps just before the PCM1804).? If one of the differential pairs looks bad, then look back, likely to the trifilar transformer.? If they all look good, it is likely the PCM1804 that is bad.

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You can take this measurement at the PCM1804, pins 4 & 5 (inphase) and the corresponding 4th & 5th pins down on the other side of the chip (quadrature).? Alternately if it is easier, you can measure at the outputs of the op amps IC405 pins 1 & 7 (inphase) and IC406 pins 1 & 7 (quadrature).? If you have a 2-channel scope, you can measure inphase and quadrature at the same time and verify that they are 90 degrees offset.? But if you only have one channel, it is ok, because if they look like good sine waves at somewhere near the expected amplitude, they are likely also offset correctly (and you can see the offset in the diagnostic IQ scan test).

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Special note: Make sure that you unplug the paddle/key and/or put the QMX in practice mode before doing this measurement.? Because if you accidentally bump the key and transmit into your signal generator, it will likely destroy it.? Don't ask me how I know....

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Stan KC7XE

Hi Cal,

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you might have missed it with all the post coming in on this topic.

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I made a stupid mistake during the first measurement and the reset powers the relays off.

Only relay 1, which toggles the capacitances between antenna and transceiver side powers up.

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73

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DK7CVD

I neglected to do and also snapped a wire off T401, never before having seen ferrites with such sharp edges.?
As I spread the leads of the trifilar T401 toroid to mount it on the board, one of its leads broke off where a sharp edge on the ferrite had nicked it.?

I was lucky to successfully splice back the broken lead with solder and to secure it with a hemostat while soldering T401 onto the board.?

The manual and support are otherwise excellent.? This was my only mishap while building the QMX+.?
The radio lit up without a puff of smoke and is now on the air!

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Hi,

Got a QMX on the workbench, and pulled up the terminal emulator window to run diagnostics. I'm currently seeing a great yellow trace on the ADC/IQ sweep that looks normal, but a very very erratic red trace. Definitely not a sine wave and absolutely not 90 degrees out of phase. Is this looking synonymous with a PCM1804 failure, or T407? (the trifilar one) being wound wrong?

--

Daniel ZL2DTL/ZL4YOTA?

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Thank you, STAN
My QMX symptoms are:
 < loud noise and (nearly) no real signals when receiving >
seem to be very similar.
I'm starting to suspect PCM1804.

I also carefully checked L401a/b and T401 along with the surrounding capacitors. But I'll check it again.

and I would like to post images using PuTTY soon.

Thank you very much.
Mitsu JK1PDR

I was wrong. ?It was operator error. :(

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The .zip file is okay too, Sardar. It contains only the original "legacy" .hex file in it, if the correct branch is downloaded! I don't know why github retired the old "git" utility in favor of gh. gh has had security key validity problems during updates over the last few months too.

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I was accidentally cloning the main branch and so not comparing the contents of the version1.1-beta branch zip file. Just FYI for folks, here is the (correct) command line to clone only version1.1-beta:

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$ gh repo clone AC8L/QMX_Plus_Autotuner_Internal_Battery_Speaker -- -b version1.1-beta --single-branch

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gh is picky about syntax and I'm very pleased that I figured this out (I hope) so I'll have the correct fileset!

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73,

Cal (AD8Q)

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On Sun, Nov 17, 2024 at 06:30 PM, Cal (AD8Q) wrote:

Hi,

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I have previously built a 50W PA for 40m that has been great. I would like to build another to use with my mid-band QMX with 17m. The 50W PA comes with components for 80, 40, 30, or 20m, but the manual says suitable components can be used to build the low pass filter for other bands. According to the 50W PA manual, the difference between the components supplied with the 50W PA and the regular QRP Labs LPF are: 1) the powdered iron toroids (3X T50-6 are supplied with the PA) and 2) NP0/C0G capacitors with a higher voltage rating.

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For the capacitors, I have found this kit that includes the same values specified in the QRP Labs LPF manual for 17m (100 and 270pf):

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For the toroids, I used this calculator to determine the number of turns for a T50-6 with 0.6mm magnet wire to be 12 for 548nH and 13 for 668nH to match the inductance values in the QRP Labs LPF manual for 17m:

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Before I purchase parts and do the build, I just wanted to ask if anyone else has successfully done the same already and if there is anything that I am overlooking. I have built several kits successfully, but this would be my first build where I am not just strictly following what is in the manual.

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Thanks,

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Jared

N7MAW

On Sun, Nov 17, 2024 at 05:54 PM, <me@...> wrote:

Just file was renamed.

I found the problem, Sardar. There are two ATU .hex files in version1.1-beta and they are different (as reported by my "diff" check). This one is up to date:

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However, there's also a .hex file in the .zip file here, which is the one I first grabbed, and it does not have the QRP configuration in it:

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73,

Cal (AD8Q)

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