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Re: RF output power on 160 and 80 meters

 

Thanks Curt and Enzo for the information.? I am using battery power to run the QMX + and the DC voltage is 11.8 volts. Sounds like I am good to go then.?
73,? Doug
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Re: Ultimate 3S overvoltage damage!

 

All seems to be well with my Ultimate 3S now. I misunderstood about the dBm power setting in the menu, thinking I could control the power for there (although I couldn't see how). Now if I understand correctly, it's a way of inserting the (measured) power into the WSPR signal.
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To help me visualize what's happening with the relays and filters I've soldered surface mount green LEDs and 1k resistors across the relay coils so now I have confirmation of which filter is in circuit. I've labelled the filter sockets with numbers 0 to 5 at one end and the band values at the other so I can put the filters back in the right places if ever they come out.
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Thanks again to all who helped me with this.
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73 and Happy Christmas,
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John G4EDX
Re: Qmx+ 3D printed case

 

Its a speaker, not a fan ;-) I also have a small audio amp in there.
Re: Qmx+ 3D printed case

 

On Sun, Dec 22, 2024 at 10:18 PM, Larry Przyborowski wrote:

Will you share the stl files or sell them?

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Tilting legs will be available in files section as soon as i get back to my pc in a day or two.?
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I still need to do some finishing touches on model based on notes frome this proto and finish a speaker box to accompany the enclosure.
After that files will be available for small fee to anyone interested.
Re: QMX and power bank PD

 

I use exclusively a power-bank and simple PD trigger cable for my QMX and QMX+ power.? One is 12V, one is 9V.? They work flawlessly.? And the small Anker 10000mAh power banks I use are smaller than the QMX, and have enough juice for several hours of continuous operation.? Don't hesitate to use this very convenient solution.
Stan KC7XE
Re: QMX no Tx

 

Hi Paul,
1) turn back on your SWR protection to prevent damage if something happens.
2) your power supplies and bias current are fine
3) it should be pulling somewhere near 1A on transmit
4) although most of your filter scans look like a pretty good shape, looking at the left-hand scale, you see they are not getting activated properly: the scale should be going from about 0dB down to about -35dB.? Confirmation that your transmit is not working properly.
5) your SWR scans are irregular, further confirmation that something is wrong with tx.
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First, make sure you haven't put your QMX keyer in Practice mode (a P will be in the display after the frequency).? That would cause all of the above symptoms, because transmit is disabled in firmware, and stays disabled even while running diagnostics.
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Otherwise, this type of failure almost always means that one of the following assembly issues is happening:
1) One of the ends of L502 is not connected well.? This is not uncommon, especially if your kit used the larger gauge wire.? It must be scraped well at the ends to remove the insulation, since it will not burn off.? Even the smaller gauge wire, which has insulation that will burn off with solder does not always contact well if not heated well enough - even if the solder connection looks perfect.? I recommend removing and scraping the ends of the wire, and replacing (if you had the larger gauge wire), or if you used the same gauge as for the toroids, heat it again with a soldering iron set to at least 370C, and heat each connection for at least 10 full seconds.
2) One of the connections of T501 is not good.? You said you already re-wound this.? It is not typically the windings that are the problem if you have no tx, it is the connections.? Especially the center-tap connection with the twisted wires.? Even if the soldering looks perfect, the insulation can prevent proper contact.
3) One or more of the connections of T507 is not good.? Only the one single-wire 'turn' that connects the signal to the output could prevent transmit, but I suspect that is not your problem because you are receiving well.? However, if any one of the other connections is bad, it will prevent the SWR and power readback in the diagnostics from working properly.
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Since your current draw is so low on transmit, I suspect it is one of the first two issues above.? There are several other things that can cause transmit to fail, including improperly installed BS170 transistors, and failures in some of the pre-installed surface-mount components, but these are very rare problems.? By far the above mentioned things are the most common failures.? Even if you are sure you soldered well.
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I hope this helps, and you find the problem quickly,
Stan KC7XE
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Re: Qmx+ 3D printed case

 

Ah, I see we're looking at two different efforts here. Both of you: amazing work. It's delightful to see all the creative work happening around the QMX/+.
Re: Qmx+ 3D printed case

 

That is super sharp! I especially like the fan and external access to the battery tray!
Re: QMX no Tx

 

Just a quick observation.

Your current limits look low.
Expect about 100 milliamps in Rx and close to 1A when Tx-ing.?

Maybe set your current limit to say ...? 1.25 A?

GREG KI4NVX?


On Mon, Dec 23, 2024 at 12:03 PM, Paul Bowen
<paulbowen@...> wrote:

Hi

I'm having problems with QMX version 4. It receives fine, with no issues,
but virtually no RF output. I can hear it in CW mode on another rig but it's
weak.
Using a current limiting PSU set at 11.5v .05 Amps RX .070 Amps TX.

In hardware tests mode the SWR jumps around even when the dummy load is
connected.
Using the Putty terminal emulator the SWR has very random values in every
band. Refreshing just comes up with a different set of values between 1 and
10.

I have rewound the Really Weird Twisted Sisters Transformer and turned off
the SWR protection. Checked the whole board with a microscope any
suggestions would be gratefully received.

Cheers

Paul
M0PNN
USB-C to USB-C cable recommendation

 

Would someone recommend a good well RFI shielded short (1-2 feet) USB-C cable?
Hiroki AH6CY
Re: QMX no Tx

 

Paul, is that a typo on your psu settings, or is that really only 70mA on TX? If so that definitely will give you low output. What current are you drawing as metered on your psu during TX? 73 Nick G0OQK
QMX no Tx

 

Hi

I'm having problems with QMX version 4. It receives fine, with no issues,
but virtually no RF output. I can hear it in CW mode on another rig but it's
weak.
Using a current limiting PSU set at 11.5v .05 Amps RX .070 Amps TX.

In hardware tests mode the SWR jumps around even when the dummy load is
connected.
Using the Putty terminal emulator the SWR has very random values in every
band. Refreshing just comes up with a different set of values between 1 and
10.

I have rewound the Really Weird Twisted Sisters Transformer and turned off
the SWR protection. Checked the whole board with a microscope any
suggestions would be gratefully received.

Cheers

Paul
M0PNN
Re: Severe QMX+ audio distortion

 

When you do, remember to set the mode to digital, not cw.

73
Roger
8P6RX

Get
On 23 Dec 2024, at 11:43, "G0TXL via " <pelliott.co.uk@groups.io target=_blank>[email protected]> wrote:

On Mon, Dec 23, 2024 at 03:37 AM, N4REE - Bob wrote:
It seems to me that "severe" and "awful" are extreme adjectives that deserve comparison.? "Awful" compared to what?? For example, Thomas Witherspoon often praises the audio quality of the Penntek TR-45 Lite. In comparison, I find my QMX (same audio circuits as QMX+) to sound better than my TR-45, and less tiring to operate.? To what field-portable QRP rig are you comparing the QMX+ ?? (Anans and Flexes are probably not fair comparisons.)
--
72 de N4REE, Bob Easton - QRP CW forever
I didn't realise the QMX+ would demodulate ssb, I thought with the great narrow filters it was optimised for cw.?
I must give it a try when I get back to my rig.
?
Paul
?
--
G0TXL (Paul)
Re: QMX+ with Macbook Air (Sonoma OS)

 

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Thanks to all who have chimed in on this thread.? A special thanks to Pierre, VE3HQZ for the detailed description of his process.? I am now armed with the knowledge I need to proceed with the QMX+/Mac integration.? My hat is off to this amazing group of helpful hams.

Merry Christmas! For those who celebrate, may your holiday be filled with the joy and peace that Christmas brings.? And to all, may this season be a time of warmth and togetherness.

Joe K8FC
Re: QMX and power bank PD

 

Gust, I didn't mean to put you off from trying PD power banks. They do work quite well. I and others on this forum are using them successfully. All solutions have quirks. You just need to be aware of them. The advantage of a power bank is that you can also use them to power other equipment with different voltages and connection types. It's a versatile and flexible solution.
--
73, Dan - W2DLC
Re: Qmx+ 3D printed case

 

On Mon, Dec 23, 2024 at 06:41 AM, David Wilcox K8WPE wrote:
You might want to cover the inside of the case with copper foil if you find you have problems. ?The metal factory case is metal for a reason.
Good results have been reported using copper spray paints like these: ?
The nickel might be cheaper, the silver might work better.??
Folks are using them to metallize 3D-printed waveguide components, shielding an HF radio enclosure should be easy.
Don't forget ventilation holes, plastic doesn't conduct heat like aluminum.
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73, Don N2VGU
Re: QMX+ with Macbook Air (Sonoma OS)

 

Merry Christmas Joe!
N1MM+ works quite well on the newer M processor Macs by using Parallels and installing Windows 11 Pro ARM in a virtual machine.? USB drivers are different for Windows ARM vs Intel based so if the built-in drivers don't work, an ARM version must be installed.? They are readily available.? The downside to this is cost of annual subscription to Parallels ($99) and purchasing a license key for Windows.? The latter can be obtained generally for less than $30.? If you decide to go this route, there are complete details posted on the N1MMLOGGERPLUS groups.io.??
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As Pierre, VE3HZQ said, SkookumLogger is a close N1MM+ Mac equivalent that works quite well.? I personally like what to me is a cleaner, easier on the eyes screen.? SL has one of the best, if not the best, CW contest practice emulators around.
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Question to you, Pierre as you said it is not able to control the QMX+.? I looked in my SL and see the Kenwood TS-480 can be selected as the radio which is supposed to work.? Is that what you are selecting?
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Merry Christmas to all!
Ron, WU4G
Re: QMX and power bank PD

 

Thank you gentlemen, knowing this I decided to not bother with a power bank PD solution.
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73 es dx
Re: QMX and power bank PD

 

I will add to what Dave has written that I don't recommend the PD triggers with the voltage and amperage indicators built in. The generate a small , but regular RF beep noise un the radio every time they change read modes. Instead, get one of those small panel ammeter/voltmeters and mount it in a mint tin to carry with your kit.
--
73, Dan - W2DLC
Re: QMX Oscillating SWR

 

Thanks for the confirmation Steve.
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