Re: QMX AGC... any progress?
I posted a couple days ago about a super simple albeit kludged option involving some diodes to limit the voltage on the headphone cable.? Might be worth trying.
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Come on Bruce, get it right.? LOL..? I took a jumper from the RF connector shell and touched the ground connection on the power connector and it fired up.? I normally fill the holes up on the power connector but did not do it this time.? I filled up all 3 holes and all is well.
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Ok. So no output at the dummy load.
I would now start working backwards from the BNC socket centre pin,through the LPFs to the PA, checking for continuity. QDX turned off, ok!
I suspect you have a poorly soldered toroid.
Roger
Get
Correct, pulsing. I didn't hold it the keys down until you suggested that, lol. OK, my dummy load does have a power meter attached. It's analog and the needles do not move at all. I'm not sure about measuring the voltage across the dummy load, though. That I've never done.
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Correct, pulsing. I didn't hold it the keys down until you suggested that, lol. OK, my dummy load does have a power meter attached. It's analog and the needles do not move at all. I'm not sure about measuring the voltage across the dummy load, though. That I've never done.
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Re: #QMX Tweeking QMX output power
#qmx
If you review the as designed turns and inductance and compare with
measured or even calculated inductance, you'll see why L513 turns need
to be tight together or add one turn and spread them. I mod L513 on my
builds and leave the rest of the LPF inductors alone (evenly spread).
To each his own.
-mike/w1mt
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On Thu, Aug 24, 2023 at 7:50?AM howard winwood G4GPF <winwoodh@...> wrote:
Why? Nobody will know the difference, you are chasing unicorns, leave it as it is and use it.
On Wed, 23 Aug 2023, 19:18 Cliff, <ae5zaham@...> wrote:
I ended up adding a turn to the L513 toroid for 20-30M. Gave me an extra watt. Squeezing the turns helps some so figured adding the turn was going the right way. It may not always work that way depending on circuit values.
73,
Cliff, AE5ZA
On Aug 23, 2023, at 13:09, Randy <wrmoore47@...> wrote:
I'm getting a little over 4 watts into a dummy load on 80m and 60m. All other bands are 3.0w-3.5w. I would like to get all bands >=4.0 watts. I've tried compressing and expanding all the low-pass filter torroids. Its difficult to get much movement out of the turns, and hardly any change in output power. For one thing, I guess I wind my torroids fairly tightly, and for another all the LPF torroids are squeezed onto the board such they all touch one or more other components and I can't get some turns moving around the contact with those components.
I probably should be happy with what I've got, but are there other tweeks I should be trying? If anyone has gotten higher output by tweeking the LPFs, let me know which ones and whether you compressed or expanded. Or if you added or removed turns.
73,
Randy, KS4L
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Re: QMX and FT8CN audio issue - strange issue
Did anyone already find a solution for the problem with FT8CN?
Sometimes the first transmission works, often even not the first one.
The QMX just shows two Dots, as a sign of not enough signal and no tx signal at QMX.
Changing the Riese Threshold did not change the behaviour...
With WSJTx on Windows it is more reliable as long as you have the "Power Slider" on 100%, otherwise same situation with the two dots and no transmission
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By 'a single slow flash', I am assuming you mean 'pulsing', while
you hold down 't'.
Good.
Does your dummy load have a power meter attached, or can you
measure the voltage across the dummy load when transmitting? That
will give an idea of whether your signal is getting all the way
out to the antenna socket.
Roger
On 24/08/2023 07:52, Wayne Greene
wrote:
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I get a momentary single fast flash on the LED and PTT Signal in
putty shows on, then off when I run a PTT test. I get a single
slow flash on the LED when I run a PTT and Transmit test and the
PTT Signal and Transmitter shows on, then off.
Wayne
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Re: New QRP-Labs product idea? A QMX/QDX based digimode / cat interface?
On Thu, Aug 24, 2023 at 07:48 AM, Scott W8RBY wrote:
Lex,
Maybe this is what you are dreaming of?
73
Scott
?Yeah...that Digirig is fantastic. I have one for my G90.??
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I get a momentary single fast flash on the LED and PTT Signal in putty shows on, then off when I run a PTT test. I get a single slow flash on the LED when I run a PTT and Transmit test and the PTT Signal and Transmitter shows on, then off.
Wayne
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Hi All,
First time post in this group for me though I have been lurking for some time ?
Having recently discovered QRP Labs and being immediately impressed with the engineering within the QMX (congratulations Hans ??) I decided to take the plunge and whilst waiting to start my QMX build I have been musing over a suitable portable power supply.
For some time now I have constructed battery packs for my home brew projects because it gives me full control over the capacity and the scope of inbuilt protection, I decided in this case that it would also be nice to include some form of fast acting solid state over current trip i.e. an electronic fuse in addition to the traditional battery management / protection board. ?I was about to start recalculating component values for a design I had used previously but decided also to have a look at what might be available at low cost commercially and in doing so happened across this device?? Given the 1A/2A selectable trip levels and the relatively low price I’m going to order one and have a play with it. ?I thought in the meantime it might be of interest to others as the current range would seem to be compatible with QRP current drain.
73 de Clive, G4KCM
SAFETY NOTE… ?I have a background in industrial electronics and control systems. Given the energy involved if you do not have appropriate skills it is safer to avoid working on high capacity batteries. ?My wife is a fire fighter in London and the recent up kick in battery related ‘incidents’, be it EVs or in domestic premises, is scary. ?I predict it to get worse as competition increases in the EV sector!
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Willie - yeah its kinda weird. Even if I go to clock settings and force an update it can sometimes not sync, even trying different servers. I assumed a wi-fi lag
Jim - JTsync sounds cool. Except for ft-8 I really dont care if the clock is off a few seconds.?
--
regards,
Bryan, N0LUF
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Re: #QMX Tweeking QMX output power
#qmx
Why? Nobody will know the difference, you are chasing unicorns, leave it as it is and use it.
I ended up adding a turn to the L513 toroid for 20-30M. Gave me an extra watt. Squeezing the turns helps some so figured adding the turn was going the right way. It may not always work that way depending on circuit values.
I'm getting a little over 4 watts into a dummy load on 80m and 60m. All other bands are 3.0w-3.5w. I would like to get all bands >=4.0 watts.? I've tried compressing and expanding all the low-pass filter torroids. Its difficult to get much movement out of the turns, and hardly any change in output power. For one thing, I guess I wind my torroids fairly tightly, and for another all the LPF torroids are squeezed onto the board such they all touch one or more other components and I can't get some turns moving around the contact with those components.
I probably should be happy with what I've got, but are there other tweeks I should be trying? If anyone has gotten higher output by tweeking the LPFs, let me know which ones and whether you compressed or expanded. Or if you added or removed turns.
73, Randy, KS4L
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Re: New QRP-Labs product idea? A QMX/QDX based digimode / cat interface?
Lex,
Maybe this is what you are dreaming of?
73
Scott
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So if you attach a dummy load and do the transmit test, what happens?
Roger
Get
Yep. Here is my RF Filter Sweep:
I also ran a VN command in CAT command test and got the correct firmware version as a response.
Wayne
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Yep. Here is my RF Filter Sweep:
I also ran a VN command in CAT command test and got the correct firmware version as a response.
Wayne
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Can you access the QDX using the terminal interface? i.e using
Putty?
If you can, and you have a dummy load, you can run the RF sweeps
and test CAT and transmit.
That should tell you if the USB link is good. That said, a lot of
people have had USB cable issues...so it is well worth trying
different cables.
Roger
On 24/08/2023 07:21, Wayne Greene
wrote:
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Thanks, Roger. The waterfall isn't showing
anything. I'm really thinking this a sound card issue, but I've
looked at everything I can think of related to audio devices in
my computer.
Could it be something with the USB jack?
Wayne
On Thu, Aug 24, 2023, 07:13
Roger Hill < rhill@...>
wrote:
Looks ok to me.
Sorry, I can't help much more. Is the waterfall display
showing anything?
Maybe time to start checking the receive signal path back
from the antenna socket.
Roger
On 24/08/2023 07:11, Wayne Greene wrote:
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Mine had no receive as well. Turned out C509 was missing entirely which may be the cause for both of us. I will know soon as a replacement should arrive today. C509 position is on the bottom side of main board right next to R510 which is marked "103."
73
Karl
KI4ZUQ
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Re: QMX Draws 200mA when Power Applied
Plug in PCB #1 connector voltages after applying power:
Gnd = 0V
+12V = 7.15V
VCC = 1.2V
ADC_5V = 0.6V
PWR_HOLD = 7.17V
V_IN = 7.17V
PWM_5V = 0V
PWR_ON = 7.1V
Plug in PCB #2 connector voltages:
ADC_3V3 = 1.1V
VDD = 3V
GND = 0V
PWM_3V3 - 0V
LIN_REG_EN = 6.93V
+12V = 7.06V
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Thanks, Roger. The waterfall isn't showing anything. I'm really thinking this a sound card issue, but I've looked at everything I can think of related to audio devices in my computer.
Could it be something with the USB jack?
Wayne
On Thu, Aug 24, 2023, 07:13 Roger Hill < rhill@...> wrote:
Looks ok to me.
Sorry, I can't help much more. Is the waterfall display showing
anything?
Maybe time to start checking the receive signal path back from
the antenna socket.
Roger
On 24/08/2023 07:11, Wayne Greene
wrote:
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Hi Hans,
Yes transmit works fine, I've been heard at good strength on all bands right into the states on reversebeacon etc., just that receive is dead as a dodo? ;-(
but good to know, transmit enabled is ok on receive.
Paul DJ0CU G4ADF
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Clive - G4KCM
Karl
Glenn S