Help ID QDX Digital voltage and band option
Hello,
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I bought a QDX used and never got around to using it. What is the best way to tell what voltage it requires and if it is high or low band? I believe it is 12v and low band, but not 100% sure. It power on ok with different voltages, and wsjtx allows me to select any band. I didn't want to try txing since I might be using the wrong voltage. Thanks! 
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Re: SSB audio distortion #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Leaving the 20/80 BPF TXswap disabled,? I messed around with the band edges and center frequencies for 20m and ended up with this. It doesnt resemble any of the examples I've seen:
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Is this good, bad?
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I also, I found that leaving everything as is and rerunning the same calibration, I get a totally different plot!
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Lun, are you getting the same plots consistently on each consecutive run on the same band?
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I cant make any sense of this at all...
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Mel. M0KMD.
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Gibberish characters appended onto end of Message 1
I have programmed my first message into the qmx+, but when I play it back on the air, it appends lots of extra characters at the end. The characters do not appear in the message memory when you view or edit it.
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I just noticed a funny thing . My Logging software indicates the QRG? and when in A&B it indicates VFO B and not the receiving VFO A. On transmit it then changes to the QRG of VFO A but transmits on VFO B. Is there a bug in the CAT ?
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Martin
DK3UW
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Hi My reader is very erratic with a lot of *. can someone who has a good setting let me know how they are please
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Martin
DK3UW
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Re: Firmware nightmare — gibberish (!) help needed
Thanks, Hans, I think they call those "AI hallucinations"!
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Randy K7RAN
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Re: ProgRock2 programming??
Two comments here:
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- Yes, the ProgRock2 (nor the original) have coupling capacitors on their outputs.? If you aren't sure if you need one, add one!? Don't go overboard with the capacitance - perhaps a value that will provide an Xc (reactance) equal to or greater than 1/3 of the expected load impedance at the lowest frequency.?
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- Even though they are "rated" for "12 volts" don't even think about running one at that voltage:? I'd avoid going above 10.0 volts.? Either put a voltage regulator there (anything from 5 to 10 volts is fine - there's no point in more than 5) or if you do have a fairly stable 10-12 volts, a 47-68 ohm, 1/2 watt resistor in series with each (expect 40-60mA consumption - do the math) to limit the voltage.? I "discovered" that even when running from 12.0 volts (from a 7812) that the ProgRock ran very hot - and two of them failed in quick succession, hence the warning.? 5.0-9.0 volts is more or less the sweet spot.
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73,
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Clint, KA7OEI
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Re: Qmx plus rev 2 not powering up
Hi Ludwig
I have ordered the correct Mosfets should arrive tomorrow, I will measure the LIN_REG_EN and then solder the mosfets, just to confirm the LIN_REG_EN should be 12V when the button is pressed in hardware version QMX+ if QMX (No +) with different revisions might have only 6V, correct?
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73 Azgael
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Re: Low current BIAS SMPS
Or actually not! It looks as if the transistor had been in place and fallen off. When this did happen cannot be said. It even would have been possible to pass a function test.?
I’m happy that it was possible to fix it easily. This even makes building the kit more fun. The next days I will run further tests to see what I might have done wrong. But I really love the stacked design and the great debugging utility. It’s a great piece of tec! Love it!
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Re: SSB audio distortion #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Hi Lun,
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Thanks for the tip.
Sadly, it didn't work for me.
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Mel, M0KMD.
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Re: ProgRock2 programming??
I didn't add one. How does it work without some DC going to pad 6 of the unit? It seems the unit would need the pad 6 to be connected to a voltage source.
Tom
On Wednesday, April 2, 2025 at 09:16:32 AM CDT, Alan G4ZFQ via groups.io <alan4alan@...> wrote:
On 02/04/2025 13:54, Tom Smith via groups.io wrote:
> I plugged it into the equipment and it seemed to work for a few minutes then stopped. I’m not sure why but I’ll set up another unit for another frequency and see if it does the same thing. It may be something in the equipment oscillator circuitry killing the PR2 (maybe a voltage issue)
Tom,
I think I'm right in saying there are no isolation capacitors on the
Progrock's outputs.
I hope you added one.
Any voltage on the equipment's crystal socket could damage the 5351.
73 Alan G4ZFQ
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Re: SWR and PWR does not show lcd
Same Issue with mine.? QMX Rev 4, firmware 1.00.027.? No PWR nor SWR showing up. f/w issue?
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thx
JD
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Re: Debugging BS170-related issues
Yes. The stripe is on the pin 1 end of the device.
Tony
AD0VC
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This is probably a stupid question with an obvious answer, but I don't want to screw it up....
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Received replacement parts from Digikey. Removed old IC503 without incident (first time using ChipQuik).
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The replacement 74ACT08SC-ND does not have the standard pin 1 dot I have come to expect on an IC. It does have a solid, white bar. Can I assume that is the pin 1 dot ?
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Thanks and 73,
Steve, N2IC
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Re: Low current BIAS SMPS
Reminds me that an automated comparison of board images taken after assembly should be able to catch this sort of fault before it gets shipped thousands of miles around the world.? You can even see the dimples in the solder paste where the transistor didn't stick.
-- 73 -- rec -- ad5dz --
Q501???
Nice find.
Reminds me why carefully inspecting the whole board under magnification is so important.?
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Re: QMX+ TCXO calibration using PPS
I don't believe this is actually implemented in code yet.
I wanted to do something similar a few days ago.
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Julian, kf4mot
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Re: Debugging BS170-related issues
This is probably a stupid question with an obvious answer, but I don't want to screw it up....
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Received replacement parts from Digikey. Removed old IC503 without incident (first time using ChipQuik).
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The replacement 74ACT08SC-ND does not have the standard pin 1 dot I have come to expect on an IC. It does have a solid, white bar. Can I assume that is the pin 1 dot ?
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Thanks and 73,
Steve, N2IC
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Re: ProgRock2 programming??
On 02/04/2025 13:54, Tom Smith via groups.io wrote: I plugged it into the equipment and it seemed to work for a few minutes then stopped. I’m not sure why but I’ll set up another unit for another frequency and see if it does the same thing. It may be something in the equipment oscillator circuitry killing the PR2 (maybe a voltage issue) Tom, I think I'm right in saying there are no isolation capacitors on the Progrock's outputs. I hope you added one. Any voltage on the equipment's crystal socket could damage the 5351. 73 Alan G4ZFQ
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Re: ProgRock2 programming??
Hi Alan,
Well, I thought I had the ProgRock2 programmed for the 6.6khz frequency, installed it with the two pins of a HC6 crystal base with a backside ground terminal soldered to the holder base. I plugged it into the equipment and it seemed to work for a few minutes then stopped. I’m not sure why but I’ll set up another unit for another frequency and see if it does the same thing. It may be something in the equipment oscillator circuitry killing the PR2 (maybe a voltage issue), so I’ll check that and see. It seems strange that the unit would work for a minute or two before dying.
Thanks again for your help!
Tom N5AMA
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Show quoted text
On Mar 31, 2025, at 8:56?AM, Alan G4ZFQ via groups.io <alan4alan@...> wrote:
?On 31/03/2025 13:01, Tom Smith via groups.io wrote:
The online instructions appear to be using a Linux app that I can’t find on my Windows computer. Tom,
The Windows version
is identical except that you enter a COM port number seen in Device Manager when you plug in the Progrock..
The instructions in the manual should be enough, or ask for any obscure detail.
73 Alan G4ZFQ
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Re: QMX + Backlight dimming
Hi All.? I have a similar goal-? screen is way too bright.? It does not seem to be the issue of pin 3 hitting the inductor on the power board.? So with r306, there are two solder pads on either side of the resistor.? Safe to assume that those pads are to receive a non-SMD resistor? Of course i have to yank the SMD one off the board, but then i just use the two pads for the non-SMD replacement, correct?
Thanks in advance
JD
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I reached out to Jeff through the web interface for this group.?
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He found a few issues with my mid band QMX, a couple of shorts (one of which took out my smps and cpu) and a few other minor issues (we both believe that my buttons might have gotten some Flux in them as they felt gummy to both of us).
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Fortunately he had the tools to replace the cpu because I don't!? He also does great work.?
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With that, I'll likely be a little bit captain obvious:
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Make sure that the QMX is connected to the computer before even plugging in power to the unit.? Then turn it on.? This often resolved new units not connecting.?
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Look very closely for possible solder shorts. I thought I did a good job of this, but the smps and cpu says differently.
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Until you get the new firmware loaded and are ready to start testing the unit in full, use a current limiting power supply and set it to no more than 400 mA.?
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Braden Glett
Randy K7RAN
Jason