Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
IIRC, Hans already has stated that the calibration must be done at full power, which makes sense as it is a way of measuring, and compensating for, the non-linearity inherent in the final amplifier design. That would necessarily mean the calibration must be done at operating voltage. Hans has also suggested that the calibration isn't necessary, as he has included a set of constants that are pretty good in all of the cases he has tried, but that calibration will definitely improve the radio's performance.... Which for most hams means it is, well, essential... Hans has also stated that his QMX finals easily pass the engineer's calibrated finger test, which would seem to lend some credence to those whose measurements have shown the BS170 has a too low Vds to safely operate on the lower bands. Not to disparage those making such claims, but "measuring" is "changing", in the RF world.... but you gotta start somewhere. Transistor manufacture is still a variable enough process that most transistors manufactured will exceed the standards shown on the data sheets. Alas, most is not all. -Chuck Harris, WA3UQV On Tue, 25 Mar 2025 06:57:02 -0700 "Joel W9JFK via groups.io" <w9jfk@...> wrote: I had the same thing happen... QMX+ is on the bench with the BS170's
removed, and one of them indeed tested bad. While waiting on my
replacement BS170's I am carefully cleaning out the holes. I really
don't want to deal with this again.
Would reducing the operating voltage during the calibration help
prevent it again? Does the calibration depend on the actual voltage
used to be accurate. I normally operate at 12V with a low dropout
precision regulator. If I calibrated at, say, 9V, would the
calibration be accurate for use at the normal 12V?
Just thinking out loud...trying hard not to do a second transistor
transplant. Not sure the patient would survive lol...
73,
Joel W9JFK
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Joel,
?
I calibrated mine at 11.1 volts, battery voltage dropped with 3 diodes in series and it all went well. I continue to operate at that voltage and the output is slightly lower than it was at 12 volts, but it is not a significant difference. I am not worried about the last few mW.
?
73,
Jim AC9YY
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I had the same thing happen... QMX+ is on the bench with the BS170's removed, and one of them indeed tested bad. While waiting on my replacement BS170's I am carefully cleaning out the holes. I really don't want to deal with this again.
?
Would reducing the operating voltage during the calibration help prevent it again? Does the calibration depend on the actual voltage used to be accurate. I normally operate at 12V with a low dropout precision regulator. If I calibrated at, say, 9V, would the calibration be accurate for use at the normal 12V?
?
Just thinking out loud...trying hard not to do a second transistor transplant. Not sure the patient would survive lol...
?
73,
Joel W9JFK
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Qmx Ssb intermittent transmit.
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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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Jack,
? I have been having a similar issue, and found I got wider. smoother curves on 80 meters with my QMX+ if I configured the band edges closer to the actual legal band edged, then set the center frequency near the center of that, then used O to walk through each step of configuration. However, I don't know it the mathematical result is better because of that, because I didn't notice much real difference in the final SSB output, which is what this configuration is measuring. I lack proper test equipment for that and can only judge by ear. I think, at least in my case, I'm going to have to stop messing around and let people with the proper test equipment do the measurements and come up with conclusions.?
--
73, Dan - W2DLC
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Qmx Single versus double click volume.
Very often when I do a Single click to change mode it changes band instead.
I was wondering if there’s something I can do to improve the situation. ?Is this a hardware issue or a firmware issue?
Is a common issue?
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Hey Scott, we're practically neighbors!
?
We should get together to compare notes over coffee or something. It would be good to do some audio quality QSOs with you because you're local!
?
Mario AEOGL
Saint Anthony Village, MN
?
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Hello Hans!
My QMX works great with 1_01_003 firmware. I've calibrated it and SSB reports are very good. Thanks!?
Few problems:
1. Wattmeter indicator looks like very slowly responding to actual power in antenna. As if it is averaging for couple of seconds...
2. When I use my usual PA with 1.3 input SWR (measured with NanoVNA) QMX tends to stop transmitting in several seconds due to SWR Protection. And SWR meter displays some big figures which do not exist in reality (checked with my standard SDR transiver and NanoVNA).
3. Nothing changes on PTT output during TX. 5V stays on the ring and 0V on the tip.?
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I'm still getting a weird phase error plot on 80m. It stops at 36%.? U shaped with near right angles at the corners. I tried adjusting the band config parameters, moving the centre Freq around. Still weird.? What band config settings are people using that gets a normal / full plot?
?
?
73
?
?
Simon?
VK3ELH?
?
?
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I forgot to add that with the changed centre frequency and smoother plot on 20m, the transmitted audio sounds as good as the other bands now.
Cheers,
Glenn VK3YY.
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
On Sat, Mar 22, 2025 at 11:37 PM, <adam@...> wrote:
Hans,
?
I have been having a similar issues on 20m. (20M to 10M QMX). When first running calibration, I used "R" run mode to do everything via the console.? On both 20m and 11m the Phase Error vs DAC plots finished very quickly and looked strange.? SSB effectively did not work and was just distortion on Tx.?? I re-ran BOTH Phase and USB for 20m using "O" once mode and while the Phase plot still looks strange it did change. Tx improved and I have been making contacts.?? The Phase plot changed when I ran it in "O" mode.?
?
Adam,? I had a similar wierd short plot on 20m (see earlier post on earlier beta thread with audio clips) which resulted in distorted transmit audio on 20m only (the other bands were good).? I found that going into the band configuration and changing the 20m centre frequency small amounts drastically changed the plot.? I settled on a 20m centre frequency of 14300000 which produced a smooth descending plot although not with as many points as say, 17m.
?
Cheers,
Glenn VK3YY.
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Re: #qmx #SSB Firmware beta 1_01_002 release
#qmx
#ssb
On Tue, Mar 25, 2025 at 12:30 AM, <rentwist@...> wrote:
I’ll have to look at phase predistortion, it is currently whatever default is, on I assume?
ON is default.
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
On Mon, Mar 24, 2025 at 06:31 PM, Stan Dye wrote:
With those settings turned on, you will be getting about 20dB lower of a signal from your mic to the audio path (compared to when the setting is turned off) - so it may be reacting with other downstream settings that require a minimum amplitude.
Crank up that 'global gain' parameter so the output of the EQ when 'on' will be similar to when 'off', and the choppiness should go away.
?
What is the factory default?? I must have fat fingered something.
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TNX Hans. 160,? i37 turns is about all you can wind!?
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reading this I am not near my shack so I can not look up the HAMLIB version but I did update WSJT-X and then went back to the previous Hamlib Version. and I used a different USB port. That changed the com port. Strangely the QMX in and output changed from QMX...2 to QMX...3. Once I had discovered that the QMX+ worked with the rig set to TS 480. Sometimes it is a little game what to start first but it works in the end. So I will not touch it and not venture into the improved version. Digital will not be my main focus so if it works, I am fine with the basics.? Now I will wait for the feedback from all the SSB testers before installing that.
--
Martin
DK3UW
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Re: custom QCX-mini SOTA kit (found video)
On Mon, Mar 24, 2025 at 05:40 PM, VA3CJO - Chris "CJ" wrote:
Looks like a custom bracket to hold the components together
I think that's just a cellphone mount for a camera tripod, along with a small tripod accessory bracket.? I have one that fits my QMX nicely.?
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Re: Interesting thing happened on my 20-10 meter QMX after loading the latest FW 1.01.003
On Mon, Mar 24, 2025 at 12:43 PM, <adam@...> wrote:
?I never use 11m and wonder if I can just fill that slot with the 40m config??
You don't need yo use that slot, but you can if you want.? There are several additional empty slots, just scroll further over.
?
But you will have to change one of the existing LPF filters to work on 40, and give proper harmonic rejection, while not compromising the desired bands.? This may not be easy, since most of the filters are shared between two bands.? There are only 3 LPF filter selection choices in the hardware.? I'm not sure if these can be spread across that wide of a bandwidth and still give good harmonic rejection.? 11m kind-of comes for free shared with a 10m or 12m LPF, so disabling or deleting it doesn't open a space for a distant other band.
?
But I have never worked through the details-maybe there is a combination of sharing that will work.
Stan
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Re: QMX+ Strange Audio Artifact - Help, Please...
Stan and Jeff - thanks for the hints on how to proceed. Got a trout fishing day coming up on Tuesday so it’ll be Wednesday before I can get back to the rig. Will post back results.
?
--
Jim / K7TXA
Eagle, ID
SKCC 10447T
BUG 301
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Hi George
I tested it extensively. The outputs (power in watts) is the same for the shiny black toroids.?
On Tue, Mar 25, 2025 at 6:48?AM George Korper via <georgekorper= [email protected]> wrote: Hi All,?
Are the transmission outputs on Rev. 3 boards with shiny black toroids the same as previous versions??
If anyone has tested these please reply.?
TNX and 73,
George?
K3GK
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Hi All,?
Are the transmission outputs on Rev. 3 boards with shiny black toroids the same as previous versions??
If anyone has tested these please reply.?
TNX and 73,
George?
K3GK
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Howard Lamhut
Daniel Conklin
Glenn S