On 14/01/2025 14:09, Mike via groups.io wrote: Is this just a small 'vocal' minority of builders having issues Mike, Without a proper survey how can anyone tell? On the whole do successful builders use the group much less? Thousands get sold, I'd expect most failures, for any reason, to be reported. Most failures seem to get sorted providing the owner persists. There is a core of members that diagnose, some offer physical help. What more can you ask for an advanced project? There are no doubt simpler, easier to build kits if that's what you want. 73 Alan G4ZFQ
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Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.
Don,
?I am curious as to your housing colors and orientation for your different voltages. Could you describe them or produce a picture?
--
73, Dan? NM3A
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Just finished the build. Nothing at the LCD. No voltage at pin 3 or at any lead of R47.? Would appreciate some guiidance as to how to troubleshoot.
Thanks
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Re: Blocking a band on QMX/QMX+
Larry,
????
An old post to this forum (that I can't find now)?recommended that in
the PuTTY Band Configuration screen, you change the band's "Band Name" to 0
(zero).? I've done this and it works.? It eliminates the band when
you switch the band switch from the front panel.
?
Bill
W2EB
East
Syracuse, NY
On 1/13/2025 at 4:13 PM,
Larry Christensen via groups.io < larryna0f@...>
wrote:
toggle quoted message
Show quoted text
I would like to block out the bands I don’t use.?
I asked this once before but never got an answer on how to do it if it is
possible.?
That would make moving though the bands I do use much
easier and faster.?
TIA
Larry NA0F
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Re: QMX and QDX - Not enough 5V PTT oomph
Thank you again Stan.
Ordered some 2N7000's and other bits and bobs. Got everything bread boarded and verified and am now waiting on an order of 1/4 size proto boards from AdaFruit. Will build out some dedicated, relay switched PTT attenuators of various values.?
Decided on powering the relay side with a simple USB-A cable for the 5V relay source.? ?I have had good results using PD power banks on my Q's and have leftover output ports and plenty of capacity for low amperage add on's like my mini cooling fans.?
Gosh ... This QRP'ing is great fun!? So very glad I caught the QRP-Labs bug.?
On Tue, Jan 7, 2025 at 7:17 PM, Stan Dye via groups.io <standye@...> wrote: Greg, a better solution would be to add a FET switch to turn on your relay - the gate of a FET is what the output of QMX was designed for, not to directly drive a relay.
A simple FET switch and a 470nF capacitor across the relay terminals, with a 9V transistor battery (or 5V arduino power source) would work well to switch your relay.
Stan KC7XE
?
?
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Re: Blocking a band on QMX/QMX+
Hans?
Thank you for your answer.?
I will wait for the time that change is in a firmware update.?
I know you have more important items to keep you busy.?
Larry NA0F?
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I also built mine with the 250 Ohm resistor for the LCD brightness and wired a 25Ohm pot to the case so I could control the brightness to my likeing rather than hard wire the 3 or 4 options.
But great looking enclosure!
?
Bob
KG5GTE
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I've been following QRP Labs since before its inception and praise the quality
of design, build and support for the kits, as well as the innovative
inspiration that brought them to market.
However, I'm looking at buying a QMX+ but I'm seeing lots of folk with issues
with the PSU modules and LPF's.
Is this just a small 'vocal' minority of builders having issues or has Hans
innovated a shade too far with the PSU's and pushed the limits of LPF
tolerances, introducing a measure of unreliability?
I think I have bought just about every kit that QRPLabs have released, in many
cases multiple examples, and really appreciate the value for money and the
support that the kits bring but I must admit my nervousness about aquiring a
QMX+.
comments? brickbats etc welcome. 73 Mike
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What should be the ideal values?
73! de Bekir TA2RX
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I thought about that too. Thanks for the suggestion!
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73, Dan - W2DLC
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You’d be better using high value resistors to bleed off the static, in my opinion.?
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On Tue, Jan 14, 2025 at 04:56 AM, Bruce Akhurst wrote:
Interesting. ? I built mine with built in GPS as a ‘self contained Ham Block’ ?
?
?
It has no external switches at all. ?Give it power and it runs. ?Vice versa ?
?
The programming switches are only accessible by removing the lid. ?
Bruce, That's the way I had it? but I found it awkward to have to reach into the back of the case to program the clock. Another issue has come up? which is that any static discharge from me walking around the house and then touching the little arrow lever zapps the clock into oblivion. I'm going to have to put some capacitors from that to ground to blead off static.
--
73, Dan - W2DLC
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Re: Your QMX output experiences @12volts...?..and by the way, what an amazing radio.
On Mon, Jan 13, 2025 at 09:00 PM, Bill Cromwell wrote:
I won't re-use the Anderson Power Poles for any other battery system to avoid the inevitable mixup.
?
I use both color-coding and housing orientation to avoid this; my 12V is ARES standard, other voltages have different housing colors and orientations, they will not physically plug together if mixed.
73, Don N2VGU
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The QMX has a protection circuit that will shut off the transmitter if the supply voltage is dangerously high, or too low. It will warn you by flashing the battery symbol on the front panel. I don't know if it is right, but if my QMX+ shuts the TX down for high VSWR, it loses sidetone too. The sidetone and the TX power won't come back until you cycle the radio off and then back on. Perhaps, the same is true for over voltage shutdown? Try strapping on a dummy load, applying 12.0V cycling the power, and see if your sidetone comes back. The radio is not amused by over voltage, or over VSWR, but it usually, it will survive if the insult isn't too bad. In any case, automotive batteries, and automotive chargers are verboten for the QMX. It doesn't want to see anything over 12.0V (9.0V if it was built for 9V). -Chuck Harris, WA3UQV On Mon, 13 Jan 2025 18:23:21 -0600 "K9SW via groups.io" <K9SW@...> wrote: Hello all.
I bought a built QMX, being in my early 80s and not quite up to
building a complex QRP Labs kit. When it arrived, I unpacked it and
plugged in the PS IO use for the K3. Looking at the panel, I saw the
blinking battery symbol and after some rtfming, plugged in a 12 VDC
PS. However, the QMX+ has major problems, some as quirky as a
sidetone which is sometimes there, sometimes not, and major problems
such as it does not receive or transmit any RF energy (and it’s not
in practice mode). Would ten seconds of 13.8 volts cause this
amount of disfunction?
Thanks,
Dave K9SW
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Re: QCX WARC Party - January 2025
My first participation with my new QMX, tnx for all QSO's and hpe cuagn?
?
13:00 - 14:00 4 QSO'S, 2 QCX user: DK3UW,GI0BEY
19:00 -20:00 1 QSO, no QCX user
?
73
Tom
DK3DUA
?
?
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Your fault finding approach is not really going to work. ?
You seem to be using the scope for supposedly precise DC readings and not providing the correct power supplies to get meaningful results anyway
?
Personally, from where you are, I’d remove all your BS170s and do full voltage and resistance checks to /from the Drain connections.
?
Also look hard at the waveforms on the gates?
?
?
?
?
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It was clearly working when it was dispatched ?- so we will shortly know. ?(Unless you transmitted I’d be surprised but … )
?
I would suggest getting set up for a logical test process,
Dummy load, power meter, whatever multi-meters etc. you have and ask again?
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Re: Cannot change the mode on QMX+
Thank you so much Stan. This did solve the problem to a certain extent. That is, once I change the mode to digi using Putty as per your instructions I can control the rig via WSJTX without any problem, changing band, etc. and yes, the dot appears under A, too.
Furthermore when I click the encoder knob the rig goes into CW mode too. However it then gets stuck in that mode and I can change neither the band nor the mode, unless I go back to Putty. Interesting in deed!
73!? de Bekir TA2RX
On Mon, Jan 13, 2025 at 02:30 PM, ta2rx bekir wrote:
Test PTT is RED
Test PTT turns RED when you activate it to remind you that TX is on.? That is normal.
You need to check if it is working by looking at the QMX+ display and seeing if the PTT 'dot' shows up under the A (or B) VFO indicator.? And yes, this only happens in QMX+ is in digi mode.
?
Make sure in the WSJTx radio control panel that 'mode' is set to 'none' (that isn't your mode problem, but can cause other probs if set incorrectly).
?
As a possible work-around, until you figure out the left encoder button issue, try sending the mode command via CAT as follows:
- close wsjt-x
- open putty and go into the QMX+ menu
- choose "PC and CAT" then "CAT command test"
- at the bottom of the screen on the "Command:" line type MD6 and hit enter.
That should switch you to Digi mode.?? MD3 to go back to CW, MD6 for Digi.
Then go back to WSJTx and have fun.? It should be able to change bands for you.
?
Stan KC7XE.
?
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Interesting. ? I built mine with built in GPS as a ‘self contained Ham Block’ ?
?
?
It has no external switches at all. ?Give it power and it runs. ?Vice versa ?
?
The programming switches are only accessible by removing the lid. ?
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Re: QMX(+) Build experience, Poor Audio Filter Sweep/RF Filter Sweep/Image Sweep/ADC IQ test and resolution with new PCM1804
I am, in all likelihood, one of those hit by the? PCM1804 problem.? I have read threads about replacing it
and bought replacement chips and the necessary tools, but I doubt my eyesight and? dexterity are equal to the task.
Wrecking my QMX is the most likely outcome.
?
I would rather restart the build with a PCB known to contain a good PCM1804. Buying a new QMX (which would be my third,
since my first was accidentally destroyed) is expensive. If replacement PCBs (just the part containing the PCM1804) were
available, I would buy one, reusing the SMPS, front panel, and all salvageable components.
?
I think Hans could consider making such replacement PCBs available at or near cost to previous buyers of a QMX,
on a one-for-one basis. I also? feel warning should be given to prospective builders that there is (aparently) a 15%
chance of having to replace a SMD component, something which is at the boundary or beyond of what many of us
can tackle.
?
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Mike
Daniel Conklin
Donald S Brant Jr
Bruce Akhurst