OK. Your screen shots all look good * except * for output power and SWR.
Is there a chance you have swapped the primary and secondary windings on T507? That would block RF output and mess up SWR.
JZ
Burt, I'll check out you screen shots later. Thanks for posting them.
Burt, That current draw in TX is quite low. Check continuity through L502.
In TX the four PA transistors will have an RF square wave signal at the gates . The magnitude of that signal is 5 volts and an oscilloscope will show that. As the duty cycle is 50% a multimeter will read 2.5 volts.
The primary side of T501 should have a DC potential in the range of 9-12 volts on each of 3 pins but during transmit the drain terminals will also have an RF signal riding on that voltage of approximately 45V p-p. At the secondary side? in TX you should see? 15-25 volts p-p RF voltage with no DC bias. These are all from memory and are approximate.?
Hope that helps and GL? 73 JZ KJ4A?
On Mon, Mar 4, 2024, 9:24?AM Burt Wizeman < burt@...> wrote: Hey John, thanks for the reply:
All bands no power out.
Verified that no input exists to the antenna tuner.
12 Volts for power.
97 milliamps on receive.
60 meters - 141 Milliamps xmit
40 meters - 154 Milliamps xmit
30 Meters - 177 Milliamps xmit
20 Meters - 207 Milliamps xmit
80 Meter - XMIT Disabled -?
I did a jeweler's loop inspection and checked continuity for the Transformers.? Was wondering what the voltage readings should be at the pads for T501 and T507.? Also, do you know the expected Bias on Transmit for QW503-Q506?? Will check C526 specifically.??
Burt
K4SRQ
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Hello to the group. I have a functional 20 Meter QCX mini, that seems to have a buzz sound on the input but seems to be present also on transmit. My other radios are quiet on 20 meters with the same input (antenna, EFHW) I have been unable to pin point the cause. It's only when switched to the active antenna, no noise when on the dummy load. I'm open to suggestions on where to look if anyone has any ideas. Thank you to the group.
Doug? ?WX7J
Sent from my T-Mobile 5G Device
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Re: QMX and FT8CN audio issue - HANS PLEASE CAN YOU NOTE??
Is there a resolution to the lack of xmit audio ? (Which I am experiencing ATM with v.017 on the QMX, and v0.92 of ft8cn.
TIA for any sort of answer !
es vy 73 de "Baab" w9ya
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Burt, I'll check out you screen shots later. Thanks for posting them.
Burt, That current draw in TX is quite low. Check continuity through L502.
In TX the four PA transistors will have an RF square wave signal at the gates . The magnitude of that signal is 5 volts and an oscilloscope will show that. As the duty cycle is 50% a multimeter will read 2.5 volts.
The primary side of T501 should have a DC potential in the range of 9-12 volts on each of 3 pins but during transmit the drain terminals will also have an RF signal riding on that voltage of approximately 45V p-p. At the secondary side? in TX you should see? 15-25 volts p-p RF voltage with no DC bias. These are all from memory and are approximate.?
Hope that helps and GL? 73 JZ KJ4A?
On Mon, Mar 4, 2024, 9:24?AM Burt Wizeman < burt@...> wrote: Hey John, thanks for the reply:
All bands no power out.
Verified that no input exists to the antenna tuner.
12 Volts for power.
97 milliamps on receive.
60 meters - 141 Milliamps xmit
40 meters - 154 Milliamps xmit
30 Meters - 177 Milliamps xmit
20 Meters - 207 Milliamps xmit
80 Meter - XMIT Disabled -?
I did a jeweler's loop inspection and checked continuity for the Transformers.? Was wondering what the voltage readings should be at the pads for T501 and T507.? Also, do you know the expected Bias on Transmit for QW503-Q506?? Will check C526 specifically.??
Burt
K4SRQ
|
Burt, That current draw in TX is quite low. Check continuity through L502.
In TX the four PA transistors will have an RF square wave signal at the gates . The magnitude of that signal is 5 volts and an oscilloscope will show that. As the duty cycle is 50% a multimeter will read 2.5 volts.
The primary side of T501 should have a DC potential in the range of 9-12 volts on each of 3 pins but during transmit the drain terminals will also have an RF signal riding on that voltage of approximately 45V p-p. At the secondary side? in TX you should see? 15-25 volts p-p RF voltage with no DC bias. These are all from memory and are approximate.?
Hope that helps and GL? 73 JZ KJ4A?
On Mon, Mar 4, 2024, 9:24?AM Burt Wizeman < burt@...> wrote: Hey John, thanks for the reply:
All bands no power out.
Verified that no input exists to the antenna tuner.
12 Volts for power.
97 milliamps on receive.
60 meters - 141 Milliamps xmit
40 meters - 154 Milliamps xmit
30 Meters - 177 Milliamps xmit
20 Meters - 207 Milliamps xmit
80 Meter - XMIT Disabled -?
I did a jeweler's loop inspection and checked continuity for the Transformers.? Was wondering what the voltage readings should be at the pads for T501 and T507.? Also, do you know the expected Bias on Transmit for QW503-Q506?? Will check C526 specifically.??
Burt
K4SRQ
|
QMX Rev 3 build instructions
I have a high band Rev 3 kit ready to build but there's no Rev 3 instructions. Do I just use the Rev 2 instructions??
I really think I have missed something obvious here regarding build instructions if I have then that's typical.
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Hi to the group !
I have a few QRPLabs radios not yet assembled and I'm now considering my power supply options.? I have some hearing loss and tinnitus so a quiet radio/power supply will be a great help.? I have Pyramid brand linear power supplies in both 12V and 13.8V, cheap 12V and 13.8V switchers bought from Amazon and all components necessary to build my own linear supply.? My idea is to feed the chosen power supply through an isolation transformer (Amazon) and to add chokes to the DC output.? I have several of the toroid power chokes sold in assortments by Radio Shack (Radio Shack P/N 273-0108).? There are small chokes in the assortment rated 6 Amp and larger ones rated 20 Amp.??
My questions are, should I go with a linear PS, a switching PS, or build my own linear supply? Will the isolation transformer reduce noise? Can I use several of the Radio Shack chokes in series at the output?? Should I add additional capacitance at the output?? Will a metallic enclosure for the whole project help?? I would also use a standard (Amazon) input line filter before the isolation transformer.? I think this might be overkill but it would be a fun and interesting project.
There are a lot of very technically competent people in this group and I will very much appreciate hearing from you.
Thanks to All and Good DX !
Jim WB4ILP?
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Re: QMX Hi Band V2 Receive Sensitivity
Hi Mike. Compared to my High Band QMX, yours seems to be at least 30 dB in the deaf direction. In your case I don't think it has anything to do with the lowpass filters because your output power measurements are very good. I rather suspect your issue is in the bandpass filter circuit. Thoroughly re-check L401, C401-C404 and all associated connections. Also check T401. Lots of potential enamel removal possibilities here. If nothing wrong there, use the schematic and verify continuity from the gate of Q508 to the "RXIN" lead of L401. Verify proper operation of Q508. This FET turns the receive RF path off during transmit. It could be off all the time. Good luck .... Ron
On Sun, Mar 3, 2024 at 2:16?PM N0MPM < n0mpm52@...> wrote: I have seen quite a few a few posts on sensitivity on the High Band QMX, but I am not too sure what to do if it isn't up to snuff...My Low Band QMX sensitivity is about -107 to -109 dbm at the antenna bnc connector.? My new High Band QMX is running only about -75 to -77 dbm.? Not deaf by all means, but I am guessing it should be better.? Is this something that can be improved by fiddling around with the LPF windings?? Transmitter power is about 3.8 to 4.2 watts depending on band with the 9v transformer winding....
I appreciate any insights..
thanks and 73,
mike? n0mpm
|
Hey John, thanks for the reply:
All bands no power out.
Verified that no input exists to the antenna tuner.
12 Volts for power.
97 milliamps on receive.
60 meters - 141 Milliamps xmit
40 meters - 154 Milliamps xmit
30 Meters - 177 Milliamps xmit
20 Meters - 207 Milliamps xmit
80 Meter - XMIT Disabled -?
I did a jeweler's loop inspection and checked continuity for the Transformers.? Was wondering what the voltage readings should be at the pads for T501 and T507.? Also, do you know the expected Bias on Transmit for QW503-Q506?? Will check C526 specifically.??
Burt
K4SRQ
|
Re: Faulty Progrock2 - no response to ticket
#progrock2
Peter,
How were you powering the ProgRock2?? What sort of voltage source, voltage level, and connection method?
73 - Steve, KW4H
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Re: QMX Using Z-Match ATU Blown Finals -- Twice
The second failure was with Vcc at 9V. Power at about 1.2W.? Last sentence of the first paragraph.
--
Chuck, W5USJ
EM22cv, Rains Co., Texas
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Burt,
Some questions. Your answers may help your helper.?
Are all bands exhibiting no power out?
Have you verified 'no power' using an external instrument?
What voltage level powers your QMX? How much current is drawn in TX? In RX?
Have you checked all the solder joints at T501 and T507? Inadequate removal of enamel insulation is a prime culprit. Using an ohmmeter , check for continuity through the winding, measuring from pad to pad, not on the copper wires.
Have you inspected C526? If it is cracked you may still be able to receive but transmit will be nil.
Post a screenshot of the diagnostic page while in TX. Let's verify that PIN diode currents and PA operating voltage are correct.
JZ KJ4A?
On Sun, Mar 3, 2024, 8:13?PM Burt Wizeman < burt@...> wrote: I have no power out, yet the oscillator is working as I hear it on my DX10 when the DX10 is not connected to an ant.? I ran hardware diagnostics on the rf filters.? They were pretty much a strange cousin of the examples in the instructions.? Not smooth at all.? Side tone sounds great!? In the diagnostics, a lower SWR was shown but no power out.? Any suggestions or further info needed?? The receiver sounds great, and the menu operation is very intuitive.? Excellent work.? Just looking for some ideas on what I can check, test points in the RF and PA sections.
Burt
K4SRQ.
|
Thanks for your agc settings. I will give them a try. 73’s
On Sun, Mar 3, 2024 at 6:02?PM Steven Dick, K1RF < sbdick@...> wrote: Hi Folks.? I just want to pass along my AGC settings.? They are somewhat based on what others have posted plus some of my own tweaks. I have not spent much time on the noise filter parameter as the many times I played with it, there was not much in the way of noisy conditions.??
The receive audio on CW now sounds very pleasing to me from relatively weak signals to relatively strong signals as well as operation in a busy band. .? Outstanding Hans!??
?
-Steve K1RF
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I have discovered by accident that the HRD profile for "Kenwood TS-570" seems to work better with the QMX than most of the other Kenwood profiles. The audio does not disappear, CW reports to the logbook as CW, and the A > B VFO, A/B VFO, CW, CW-R, FSK and FSK/R buttons all work as expected.? Woo Hoo!?
73,? Ron K9ID
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I have no power out, yet the oscillator is working as I hear it on my DX10 when the DX10 is not connected to an ant.? I ran hardware diagnostics on the rf filters.? They were pretty much a strange cousin of the examples in the instructions.? Not smooth at all.? Side tone sounds great!? In the diagnostics, a lower SWR was shown but no power out.? Any suggestions or further info needed?? The receiver sounds great, and the menu operation is very intuitive.? Excellent work.? Just looking for some ideas on what I can check, test points in the RF and PA sections.
Burt
K4SRQ.
|
Hi Folks.? I just want to pass along my AGC settings.? They are somewhat based on what others have posted plus some of my own tweaks. I have not spent much time on the noise filter parameter as the many times I played with it, there was not much in the way of noisy conditions.??
The receive audio on CW now sounds very pleasing to me from relatively weak signals to relatively strong signals as well as operation in a busy band. .? Outstanding Hans!??
?
-Steve K1RF
|
QMX Hi Band V2 Receive Sensitivity
I have seen quite a few a few posts on sensitivity on the High Band QMX, but I am not too sure what to do if it isn't up to snuff...My Low Band QMX sensitivity is about -107 to -109 dbm at the antenna bnc connector.? My new High Band QMX is running only about -75 to -77 dbm.? Not deaf by all means, but I am guessing it should be better.? Is this something that can be improved by fiddling around with the LPF windings?? Transmitter power is about 3.8 to 4.2 watts depending on band with the 9v transformer winding....
I appreciate any insights..
thanks and 73,
mike? n0mpm
|
Re: Faulty Progrock2 - no response to ticket
#progrock2
Steve,
My Progrock2 initially ran very hot. I was able to connect via PC to the microUSB port and set the frequency, but at high frequencies (above 135MHz) the output becomes unstable/noisy and gives no output from 150MHz upwards.
Peter
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Re: CAT script for setting the real-time clock
The QMX firmware version1_00_015 and up implement the?CAT command TM for get/set of real time clock.
I created a small powershell script for windows to set the time (see?).
73 Stephan HB9CHM
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Good morning (In the States) Hans!
I used a little 'Burt' force, and by alternating screws from each side and opposing corners i got it together with a good fit.? Thanks, I was afraid to put too much pressure on it.? So far so good!? Just checked the receiver on 20 and it was receiving as strong as my FT-DX10.? Very excited!? Bands appear a bit dead so far today for 20.? Working through the configuration steps next and then the xmit!? A fun and challenging build and oh that wonderful feeling of completion!
Thanks,
Burt K4SRQ
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Ronald Taylor
Burt Wizeman
Chuck Carpenter