Hi Russ and Stan.? thanks for the support.? I do seem to have proper resistance between VCC adn VDD and ground.? I have ordered new boards (and in fact a whole new QMX kit just in case).
I also detected a poorly connected leg of the binocular T507 transformer.
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Hoping I didn't cook the entire radio, but will have to wait for the new boards.? I have successfully built the QCX mini and the (tr)uSDX, so crossing my fingers that I didn't fall apart on the QMX
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Thanks again for your answers.
JD
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I agree that would have been easier... but it's done now LOL... I agree, if I need to do it again, that's the plan.
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I am happy to report that the quadruple BS107 transplant seems to have been successful :)
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Running the calibration now... hoping for the best.
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73,
Joel W9JFK
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
When I use my Hermes Lite 2 or a Tiny SA it appears that my audio goes way beyond 3 KHz on USB for example both above and below my center frequency. However checking on a remote WebSDR I see what looks like a clean well defined SSB/USB signal and all my audio reports have been good.
?
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73,
Jim AC9YY
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Re: Simulation of #QMX Filters + planned 6m in QMX
#qmx
Today I soldered the original BPF configuration into my QMX 20-10.
Preliminary I bypassed the 20m LPF, and I left out the two other LPFs.
I configured all bands to use the LPF bypass and can sweep through the BPFs through all bands.
Everything works fine as I am used from the QMXs, but not as simulated ;-)
The band pass filter is much steeper than my simulation!
=> My assumption is wrong: I can't use the 10m BPF for 6m.
Maybe my configuration for the simulation is wrong?
- Did I use the right impedance (50 Ohm)?
- Is my circuit for the simulation correct??
I understand the BPF like this:
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RX IN ------ L ------ C ------- OUT
GND ---------------------------- GND
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Is this too simplistic? Is T401 to be seen as essential part of the BPF?
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73 Peter DL4PJ
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Re: Qmx Ssb intermittent transmit.
Try tightening up the ring contact on the 3.5mm jack. ?If you reach in with a very small barrow blade screwdriver you can bend that contact out to place more tension in the plug for a more reliable contact.
That fixed my intermittent on the QMX. ?On the QMX+ I installed Kobiconn jacks (Mouser) on the rear panel. I used the TRRS jack for even more retention of the plugs.
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On Mar 25, 2025, at 08:26, Petrov Sergey via groups.io <irtish71@...> wrote: ?The same with me. Smtm you need to press PTT twice to start tx. 16:35, 25 March 2025, "Howard Lamhut via groups.io" <howardlam@...>: 蚕惭齿…
I have the SSB software installed version three and made one contact with good audio reports.
The only thing that is strange is sometimes the radio does not go into transmit when I press the PTT in Ssb mode. In CW mode it works every time 100%.
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-- Sent from Yandex?Mail for mobile
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I just wound L506 with 42 turns....only because the solitary yellow core was already used making L403 !
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I wouldn't worry to much. Hans wrote regarding the calibration "The results are markedly different by band, this is normal. " and "Some phase error measurements do have weird glitches."
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73 Ludwig
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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
Finally got a 14.074 mhz signal into the QMX+ at about 17 mv. My Rigol DS1102E scope may be insufficient for this task but I can display the 17 mv signal at the BNC? but nothing at pins 1 and 7 on either IC405 or 406. So my problem? is likely back towards the BNC...
--
73
Karl
KI4ZUQ
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Hi Guys!
I managed to install the 1_01_003 SSB Beta on the weekend and
just took a few screenshots to provide another data-point for a
High-Band QMX.
Calibration was ok, but 20m and 10m look a bit suspicious. I still
need to build / adapt an external microphone.
All snapshots of my initial build and the SSB calibration on my
Google drive:
If the link gets filtered out, i give you the 20m picture inline
here:
10m looks similar
17, 15, 12, 11m more normal, as there is a dip with a clear
minimum visible in the graph.
No idea if my results are good, bad, normal, abnormal. Just
providing another set of measurements for you and Hans.
73 de Tobias DL3MHT
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First success yesterday with SSB on my QMX+ on 40m. Worked GB70RS at around 64 miles. He said the audio sounded good but to be careful of chewing the mic!
73
Tony
G3OVH
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Re: QMX+ Initial Power Up Display Shows Only Boxes
Hi Don,
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I just finished my build of the QMX+. I have completed two other successful QMX builds.
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So, today I applied power as suggested and wound up with the square box display. I figured it was the interface between the display board and the main board. I got the iron hot and reflowed as many joints as I could. After eliminating 99% of the possible I went back to the inside top header. So looking straight on from the front, over the top edge, start counting from the left to the right and pin #5 is the one. After I got the solder to flow from the pin to the pad?? --->? new QMX+ is on the air.
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Hope that helps.
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73, Dean/ N2TNN
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Re: Leaving 50-watt amplifier in-line but off
Hi Jim,
?
I do not believe the PIN diodes have enough bias (reverse and forward) to allow the external transmitter to work.? It should be easy to install a relay that bypasses the amp altogether.
?
73
Evan
AC9TU
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Dear all.
on my QMX, Rev2, 80m-20m, the diagrams for the ‘phase error vs DAC’ do not correspond to Hans' example. I have performed a factory reset. I have adjusted the band configuration: start, end and centre. See screenshot. I have disabled ‘20/80 BPF TXswap’ in the menu.
I would be grateful if someone could post the band configuration for a QMX 80m-20m as an example in this forum.
Stephan, DD6DO
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Re: Can't get SWR sweeps to be 1:1 with dummy load
Back on the air :)
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I chose in the end to just replace ic 402 and 403, and everything seems to be working fine now.
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I'm still not sure what exactly killed the chips. The limiting diode and the receive switching fet seem to be functioning correctly, but it's certainly fixed for now.
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Thanks all!
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Greg,
N1TR?
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Re: Qmx Single versus double click volume.
I actually removed the knob completely and it did not solve the issue.
so I have confirmed that there is no travel issues due to the ?knob restricting its ?movement.
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I used two different wires - The one that Hans provided and this one: . I did that in order to maintain color coding for the P and S wires. The P wire is the Amazon wire. At the very least, I seem to have cleared enough enamel to establish continuity between the center tap and the P on the other side. I'm going to try some more when I get home. Here is what I have:
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?
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On Tue, Mar 25, 2025 at 09:10 AM, Stan Dye wrote:
On Tue, Mar 25, 2025 at 08:57 AM, Chuck Harris wrote:
Unless you are using some exotic insulated wire, a few
seconds of exposure to the flame of a butane lighter will
easily burn off the enamel.
My experience is different, Chuck.? A simple roll of wire (certainly not exotic) I bought on Amazon from a quality manufacturer happens to have a high-temperature enamel.? So yes, I can burn it off, but only with with a high-temperature butane torch, but not a simple butane lighter flame nor any soldering temperatures.
Other wire types do have enamel that is specially formulated to burn off with solder or at low temperatures - you can often see it in their specs.
The .6 wire that Hans originally provided is somewhere between the two - if I didn't scrape it at least some amount, to significantly fracture its surface, it wouldn't burn off for me with soldering nor a simple lighter flame.? And I don't like to use a high-temperature torch.
Stan KC7XE.
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K used a lighter and tried scraping as well. I'm going to try with some hot solder. Thanks!?
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On Tue, Mar 25, 2025 at 08:57 AM, Chuck Harris wrote:
Unless you are using some exotic insulated wire, a few
seconds of exposure to the flame of a butane lighter will
easily burn off the enamel. After you have done that,
there will be a little oxide and smutz on the wires, so a
gentle pull through a folded piece of sand paper will
clean that right off.
Way easier than scraping, or sanding the insulation off.
-Chuck Harris, WA3UQV
On Tue, 25 Mar 2025 08:31:25 -0700 "Stan Dye via groups.io"
<standye@...> wrote:
If you didn't scrape the enamel off the newly-twisted 'A' center tap
on the right side, those two wires won't contact each other, and you
won't have continuity between the two left 'A' points - even if you
scraped the enamel off the outside of the twist. If you have the
finer-gauge wire, you can burn the rest of the enamel off with solder
and a hot soldering iron, if you have the thicker .6 wire, you need
to un-twist the A center tap and scrape the wires first, then twist.
Stan
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You're referring to the leads on the right (primary center tap), correct? If so, I did that, which I believe is how I'm getting continuity from left to right. However, I'm going to apply some solder to the twist in order to make sure that I'm not getting a false positive by touching one lead or the other. Thanks!
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On Tue, Mar 25, 2025 at 08:04 AM, <john.runchey@...> wrote:
You won't have continuity between all the P points UNTIL you twist those 2 P leads together. This threw me as well for a bit.
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In Washington DC on a beautiful day! Now to find my paddle so I can send anything apart from messages!
De AC3K
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Dave WI6R
Karl
DD6DO
Howard Lamhut