By lowering the "rise threshold" and "fall threshold" I am able to get the single dot, but still no audio out...? I set the values to as low as 40 and 20 respectively.
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As others have said the double dot indicates insufficient audio.
In Wsjtx be sure the output slider is all the way up.
Fldigi will not work with the QMX using firmware after 006. A change was made in how the transmit started and it broke the compatibility with fldigi. Also FT8CN will not work after firmware 006. Hans knows about this and I'm sure will eventually get it working.
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So, I am having some strange issues with my QMX and wanted to see if anyone else was experiencing the same.? It is entirely possible this is a configuration issue on my end but it is puzzling nonetheless.
My main issue is that I get no power out when in Digi mode connected to PC.? This is on WSJT-X, FLDigi/FLRig, FT8CN on Android, and AndFlMSG.
From the radio I can TX Morse code fine from the paddle with acceptable power output so it does not seem to be hardware related.
CAT control works and I can change frequencies fine, and RX audio is coming through and is decodable for WSJT-X.? When I TX the QMX goes into TX mode and I get the two dots below the VFO indicator showing I have a TX command as well as incoming audio, but there is no movement on my power meter at all.? I also see the expected progression on some modes of a single dot (tx command), double dot (audio comes in) back to single dot (audio stops) and no dot (rx mode again)
So the communication from the computer to the radio seems fine based on this, but I just am not getting any power out.
Firmware is 1_00_009.
Anyone else able to replicate?? Thoughts?
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I have the volume slider at maximum in WSJT-X
It appears that neither my PC nor Android phone are loud enough...? or perhaps the audio is not getting in at all?
I have the QMX selected as the input and output device in both systems on the PC.? Unfortunately I do not know how to check the output device on my Android, but there is no audio from the speaker when my QMX is plugged in, and if I unplug the speaker from the phone mid-transmission, I get the last half of the transmission from the phone speaker, so I suspect it is going to the QMX as intended.
Another odd detail is that WSPR and FSKCW beacon modes both put out a continuous tone that appears to never stop, but CW beacon mode seems to work as intended.
It's as if I have no way to get modulated audio into the rig...? Could this be an assembly or soldering error?
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I've not experienced this issue at all, my QMX works fine as expected in supported digital modes.
In your WSJT-X software, is the output volume slider all the way up at maximum? It needs to be no other place but at maximum.
Of course the QMX audio device needs to be selected in the software for both transmit and receive, but I'm pretty sure you already know this.
Hope you get this issue resolved!
73
de Roy - KI0ER
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Double dot indicates that the volume from the PC is too low to generate RF. ?From page 48 of the operating manual:
2. TX status is two dots:
This means that QMX has been put into transmit mode via an appropriate CAT command, and that it is receiving audio from the PC; however the audio level is too low, so there is no RF.
I had a similar issue and found that I had to have the volume turned all the way up to maximum in order to get RF out. Hope that helps, Jonathan KN6LFB
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So, I am having some strange issues with my QMX and wanted to see if anyone else was experiencing the same.? It is entirely possible this is a configuration issue on my end but it is puzzling nonetheless.
My main issue is that I get no power out when in Digi mode connected to PC.? This is on WSJT-X, FLDigi/FLRig, FT8CN on Android, and AndFlMSG.
From the radio I can TX Morse code fine from the paddle with acceptable power output so it does not seem to be hardware related.
CAT control works and I can change frequencies fine, and RX audio is coming through and is decodable for WSJT-X.? When I TX the QMX goes into TX mode and I get the two dots below the VFO indicator showing I have a TX command as well as incoming audio, but there is no movement on my power meter at all.? I also see the expected progression on some modes of a single dot (tx command), double dot (audio comes in) back to single dot (audio stops) and no dot (rx mode again)
So the communication from the computer to the radio seems fine based on this, but I just am not getting any power out.
Firmware is 1_00_009.
Anyone else able to replicate?? Thoughts?
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Re: QMX Case fit & finish
On Tue, Sep 5, 2023 at 12:00 PM, Rick Williams - VE7TK wrote:
i did not encounter this with my QMX build, however,I'm sort of a belt and suspenders guy. So I lined the bottom shell of the case with PVC tape before assembly to avoid shorts.
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73, Rick
VE7TK
Website:
Yeah, I was really careful about trimming the components. But the nylon screw was just big enough to interfere with the case closure. It was an easy fix, but a real bug until I identified it. The pressure on the board messed up the audio for some reason I never pinpointed. Removing the pressure solved everything.
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The CAT commands are quite clear in the manual and perhaps they interface with a pre-written APP or program ?
The question is, has anyone written something that an old man can follow easily and get results ?
Tnx,
John
kK4ITX?
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Thanks Steve and Gunnar,
I've looked it over and found a couple suspect spots that I've cleaned up. Am back on the air now and we'll see how it holds up. I'm going to run out of the case for some time to be sure all is well then try the enclosure again. I appreciate your input very much.
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On Sep 5, 2023, at 05:39, Steven Dick, K1RF < sbdick@...> wrote:
Cliff, you might have introduced an intermittent short somewhere when you took the unit apart and reassembled it. ?I would carefully take it apart one more time and reinspect all the boards. One thing I like to do as a final inspection is ?to take a smartphone photo of each side of all sub-assemblies, then, using Microsoft Paint to view it and edit the photos, add small red circles around anything suspicious looking using the shapes tools. ?After any inspection and possibly touch-up, I then put a red line through the red circle to indicate that particular joint has been looked at and touched up as necessary so you don't lose track of what you inspected. ?(See attached). ???It's some more work to do, but at least you are ruling out a newly introduced issue caused by mechanical disassembly and reassembly such as a hairline short from a tiny piece of stray clipped wire or a loose solder ball. -Steve K1RF ------ Original Message ------ From "Cliff" < ae5zaham@...> To [email protected]Date 9/4/2023 11:55:39 PM Subject [QRPLabs] Ideas please I built one of the early QMX rigs, S/N 338, and it's done great ever since, about 2 1/2 months, until last week. I gave it the ultimate test by transmitting without an antenna and not being observant so did it a couple of times. It took it at first, but eventually gave up and shorted one of the finals.
I replaced the finals and D106 zener diode it shorted also. It came up and did fine so put it back in the case. It worked for an hour or so then the same thing, short causing the power supply to current limit to 1 Amp. This time D106 was fine. I replaced all the finals and to be safe the driver IC503, 74ACT08D, chip. Tested and all ok so back in the case. Again it lasted about an hour with FT8 and bang. Same short.
What could be causing it to repeatedly fry the finals? Actually only one of the finals shorts. The other 3 all test good. The antenna is connected with SWR of 1.0. Power out on 20M is 4.5 watts and 40M is 4 watts. Now this evening with it out of the box and just replacing the one bad BS170 it's worked for an hour and a half and still is ok. Could being in the case causes too much heat build up? I don't see anywhere where the case touches anything.
Noticed today an oddity, the QMX display kind of flickers as it powers up. No flicker once it's up, but I don't remember that occurring previously. ??? It makes me think that there is something that is putting a heavy load on the voltage as it powers up so the display isn't seeing the full voltage. I don't see that indicated on the meter on the power supply.
Ideas?
Help!
73,
Cliff, AE5ZA
<inspected.jpg>
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Thanks Hans
The main reason that some feel the need for speed is that most of the DX and many of the nets run at 25 to 35 WPM. If we don't match their speed then they often don't respond. Contesters seem to do the same.
Another reason is that some of us forget what we started to send by the time we get near the end. Best to send it quickly whilst we still remember ;-)
A responsive and crisp (little need for a shaped sidetone waveform) feedback will make for a much more pleasurable experience.
73
Don
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Re: QMX low current on Tx
Well, this is no longer the first
problem.
I started checking things round the
BS170s, looking for a difference between the two banks, Was
probing voltages, in Rx mode when I saw an ominous curl of smoke.?
And the PSU had hit it's 1A current limit.? The hot spot was L101
and the resistance from VCC to ground is 13R, both ways. I guess
the D108 fuse has died, possibly Q108, Q112, D104 etc. Q103, Q105
and their friends seem OK.
It's time I sorted out some semi
professional software that's been pending for too long, that will
give me time to decompress.
I've found a 5V linear and that, with
some veroboard should be enough to keep the QMX going even without
any polarity or on/off control.? Hoping the 3V3 board is OK.
It's a fragile little prima donna.
Chris, G5CTH
On 04/09/2023 15:45, Chris wrote:
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I've been operating my QMX portable - in a field, like it's
intended.
New antenna, a DX Commander clone, which I tuned on 20m, VSWR 1.3
to 1.5 according to my NanoVNA.
Running at 11.5V with a 1A current limit.
The first day everything was fine, Tx used the usual 0.7 to
0.8A.of input current
The second day everything was still OK except that the current had
dropped. now its 0.56A on Tx. I've returned home and tried it with
the dummy load and am seeing 16.85V peak Rf = 2.83W.
This is down on what I got before, I used to be seeing 4.45W with
the same input voltage.
Do people have any ideas about why?? I suspect some of the BS170s,
could it be that half the PA is still working?? At least the
74ACT08 may be OK, although maybe half of that has gone.
Chris, G5CTH
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Re: Dire need for a part!
Actually it's still there at $4.99. Just saw it last night when I was preparing an order.
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It was $4.99 for years (USPS) but that option seems gone recently so the new minimum is $6.99.?
Over here where I live the shipping costs only about $0.75. And takes 2 days on average. But, the range of parts held by the component distributors is much less than Digikey! I'd take Digikey and $6.99 postage, being able to buy whatever I need from a stock of millions of different parts, any day! 73 Hans G0UPL?
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LOL, it isn't USD$15 today.? Wait a week or so, and it'll change.? Hi all
FYI Digikey's cheapest?US shipping option is FedEx Ground (4 days) at $6.99. Mouser's cheapest shipping option is UPS Ground at $7.99.?
It isn't $15...??
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It is up and running! C509 is the title and we have a pile of diodes and caps already to keep your inductors company!?
--
73
Karl
KI4ZUQ
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Although I'm not very qrq myself I can't get much above 20wpm on the qmx while on other rigs I can go to 25wpm. I think it's this issue. Thanks Hans for being open to fixing it!
-mike/w1mt
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Hi all
In the original post the complaint specifically was about the lag from hitting the key, to the transmitter RF starting up. At 10ms, I couldn't see why that would be poor in comparison to some highly regarded rigs like KX2 and K3S, considering a 10ms delay would be faster.?
But now I understand what you are really talking about is that the SIDETONE lags and this is objectionable. Yes, in QMX the way I have it set up now, the sidetone is synchronous with the RF, so this makes sense. And I understand you are saying you don't like this because it interferes with your QRQ'ism. (20wpm and up). Which I have never experienced because the pinnacle of my personal accomplishments to date is 16wpm, though I have been practicing a bit so I may get there eventually.?
So I will add it to my little list here, that I should move sidetone to as soon as possible after the key starts getting pressed. OK!
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Re: QDX - protection of BS17O PA
Dan,
The Zener diodes suggested have about 150% the capacitance of the TVS. The capacitance is measured at zero volts, at 9 or 12V, the capacitance is about 1/4 the value at zero volts. Each BS170 has about 20pF of capacitance at operating voltage and two are in parallel. So the TVS would add about the same capacitance that is already there, so a little less than 100pF total. Maybe not optimum but reports with Zeners don't show much difference in operation without them.
Gary
W9TD
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Re: QMX blank screen after initial load
No whining, Emory! Old guys rule...IF they can put a QMX together and it works!
--
73
Karl
KI4ZUQ
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Real men use mode B....
Not-so-anonymous
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Re: QMX blank screen after initial load
Evan Really appreciate the help. As soon as I read your email, thought why didn't I think of that. Had to take qmx all apart set brightness and it works fine. I am amazed felt sure it would not work. Have not tried transmit yet. It is a difficult kit for old guy with big fingers but so far good.? Thank you 73 Emory WM3M?
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-------- Original message -------- From: Evan Hand <elhandjr@...> Date: 9/5/23 11:54 AM (GMT-05:00) Subject: Re: [QRPLabs] QMX blank screen after initial load
Hi Emory, Have you tried adjusting the contrast potentiometer???Start with it almost fully counterclockwise. 73Evan AC9TU
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Jim,
The IRF510 is? 100V device.? FOr PA anything under 24V is safe as it goes.
That may increase power out but the amp gain does ot change greatly.
The 2.5W from the driver is likely the limiting factor as its definately down.
--
Allison
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Post online only, please no email.
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K9NUD-Steve
KK4ITX John
Don, ND6T
Karl
Gary W9TD