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Re: QDX - No RF output, Tx line stays low
Hello Ben,
I had the same issue and after Hans's explanation on what is going on in the software I switched to a different platform (went from Windows to Raspberry Pi) and the TX signal appeared.? As stated in Hans's message, he has updated the firmware to let us know what is going on in the software. A quick summary of my transmit issue was the USB link with the Windows10 computer was dropping out and a tone was not being sent to the QDX so it never went into a signal transmit, it was just ready to transmit. Note, that computer still does not link properly with the QDX.? I have other computers running Windows10 that do.? The issue is the USB link dropping. 73 Evan AC9TU PS; be careful probing around the PA MOSFETs.? A brief twitch and both MOSFETs on one side of the push-pull amp let out the smoke.? It also took out IC5, the 74ACT08 PA Driver.? Asl me how I know.? Let's say I have practice now with repairing the full transmitter power chain.? The QDX is a very small device for this 69-year-old body to handle.? Extra care is required on my part. |
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Re: CAT Problem maybe?
¿ªÔÆÌåÓýThanks Hans
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This terminal emulation etc is a bit new to me, I have PuTTY working but like a man with no arms!! Hopefully you can check it, I think you are using WSJT-X? I got some data in the log file but not sure what I am looking at lol. Will keep at it.
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73
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Ian G4GIR
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Re: QDX - No RF output, Tx line stays low
Hi Ben? See my message earlier about 1.01c. And install 1.01c. The diagnostics on the status LED will help understand what's going on.? The TX signal on the schematic is more of a "key down". It won't happen until the QDX receives an audio stream.? 73 Hans G0UPL http://qrp-labs.com -------- Original message -------- From: "Ben Bangerter, K0IKR via groups.io" <bwbangerter@...> Date: Sat, Nov 13, 2021, 12:06 AM To: [email protected] Subject: [QRPLabs] QDX - No RF output, Tx line stays low I assembled my QDX this week, built for a 9v supply. ?All went well, interfaced with WSJT-X v2.5.1 on Toshiba laptop running up-to-date Windows 10. ?In WSJT-X under settings, the Audio tab shows ¡°Digital Audio Interface (QDX Transceiver)¡± as present for both Input and Output, and selected. ?The Radio tab shows Rig as Kenwood TS-480, CAT Control over Serial Port COM3, and PTT method CAT. ?Test CAT works, Test PTT puts QDX into Transmit mode it appears, with the LED?triple light flash mode on the QDX. ?The receiver works fine on all four bands. ?BUT there is no RF output at all. ?Putting the QDX into transmit with Test PTT in the Radio tab, or Enable Tx, or Tune, causes the LED to flash, but no RF output. ?Scoping the unit out, I see no signal on the gates of the BS170 transistors. ?Examining IC5, the 74ACT08, I see CLK0 at pins 9 and12 and CLK1 at pins 1 and 4 both present at expected levels. BUT the Tx line is low in both Receive and Transmit modes. ?So the outputs on pins 8/11 and 3/6 are always low, thus no drive to the BS170s. Resistance checks on the Tx line with the QDX not powered show 10K Ohms to the +5 volt rail (through R5) and 12.5K Ohms to ground. ?So there does not appear to be a short holding Tx low. ?Looks like something is pulling Tx low at all times, in both Receive and Transmit modes. ?Hard for me to see how it could be anything other than the microcontroller. ?Has anyone else experienced this with the QDX? ?I installed firmware 1.01a and the EEPROM.QDX and that made no difference. |
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Re: CAT Problem maybe?
Hi Ian? That must be correct, it just means pressing PTT doesn't generate any audio. Hence no RF. It presumably just activates RX/TX changeover only but doesn't generate RF.? I can't check this now... But probably someone else can comment?? 73 Hans G0UPL http://qrp-labs.com -------- Original message -------- From: "Ian G4GIR via groups.io" <i.frith@...> Date: Sat, Nov 13, 2021, 12:14 AM To: [email protected] Subject: Fw: [QRPLabs] CAT Problem maybe?
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Fw: [QRPLabs] CAT Problem maybe?
¿ªÔÆÌåÓýSorry Hans
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To be a bit more specific, the problem is that the QDX won't go into TX when just using WSJT-X, when the PTT is clicked in the WSJT-X RADIO settings window, so the other software is irrelevant to the problem but maybe connected?
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When?when the PTT is clicked in the WSJT-X RADIO settings window,?the QDX LED has just 1 flash, running the .c firmware
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73
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Ian G4GIR
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Re: QSX 10W Linear PA Problem.
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QDX - No RF output, Tx line stays low
I assembled my QDX this week, built for a 9v supply. ?All went well, interfaced with WSJT-X v2.5.1 on Toshiba laptop running up-to-date Windows 10. ?In WSJT-X under settings, the Audio tab shows ¡°Digital Audio Interface (QDX Transceiver)¡± as present for both Input and Output, and selected. ?The Radio tab shows Rig as Kenwood TS-480, CAT Control over Serial Port COM3, and PTT method CAT. ?Test CAT works, Test PTT puts QDX into Transmit mode it appears, with the LED?triple light flash mode on the QDX. ?The receiver works fine on all four bands. ?BUT there is no RF output at all. ?Putting the QDX into transmit with Test PTT in the Radio tab, or Enable Tx, or Tune, causes the LED to flash, but no RF output. ?Scoping the unit out, I see no signal on the gates of the BS170 transistors. ?Examining IC5, the 74ACT08, I see CLK0 at pins 9 and12 and CLK1 at pins 1 and 4 both present at expected levels. BUT the Tx line is low in both Receive and Transmit modes. ?So the outputs on pins 8/11 and 3/6 are always low, thus no drive to the BS170s. Resistance checks on the Tx line with the QDX not powered show 10K Ohms to the +5 volt rail (through R5) and 12.5K Ohms to ground. ?So there does not appear to be a short holding Tx low. ?Looks like something is pulling Tx low at all times, in both Receive and Transmit modes. ?Hard for me to see how it could be anything other than the microcontroller. ?Has anyone else experienced this with the QDX? ?I installed firmware 1.01a and the EEPROM.QDX and that made no difference.
73, Ben ?K0IKR |
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Re: CAT Problem maybe?
¿ªÔÆÌåÓýThank's Hans I will go through that.
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But could you just check the Radio settings in WSJT-X?to see if QDX transmits when you click PTT?
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73
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Ian
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Re: CAT Problem maybe?
Hi Ian? I don't know anything about those softwares or the answer to your problem.? But... If you want to check if QDX is asked a CAT command which it doesn't understand, the QDX log file is intended precisely for this purpose. So open up a terminal emulator and enable logging of errors. Any CAT commands which QDX receives but can't understand, it will log it in the error log. After trying all the things that don't work... You reconnect to the terminal emulator and take a look at the log file to see what happened. Then tell me and I can add support for any missing CAT commands.? 73 Hans G0UPL http://qrp-labs.com -------- Original message -------- From: "Ian G4GIR via groups.io" <i.frith@...> Date: Fri, Nov 12, 2021, 10:32 PM To: [email protected] Subject: [QRPLabs] CAT Problem maybe?
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CAT Problem maybe?
¿ªÔÆÌåÓýHi all,
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Just finished the QDX construction, no problems at all apart from only getting 4 Watts out on all bands, guess the other watt has been slated for the Angels Share (JD).
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However, I am trying to use QDX with Logger 32, which can log from JTDX or WSJT-X.
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I want to use the cherry picker mode in Logger 32 which isn't working. When I say it isn't working, I mean JTDX won't go into TX when told to by Logger 32.
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I don't believe it is a Logger 32 problem.
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When using WSJT-X or JTDX stand alone, I set the radio settings to the QDX requirements, click the TEST button which comes back GREEN, then click the PTT button but the QDX doesn't go in to TX.
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But when using WSJT-X and JTDX calling CQ or answering CQ's the PTT works fine.
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Could this be a CAT Command problem?
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73
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Ian G4GIR
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Re: QDX's DC connector common to 9V and 12V builds a potential problem?
My guess would be that flexing might cause the connection on the PCB to break, creating the potential for a short. That could be addressed by feeding the wires through a strain relief in place of power jack. Then you could attach whatever you want to the wiring outside the QDX without a care.
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¡ªMike Perry, WA4MP On Nov 12, 2021, at 10:21 am, Bill Lamm <kd9mdl@...> wrote: |
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Re: QDX's DC connector common to 9V and 12V builds a potential problem?
On Fri, Nov 12, 2021 at 11:49 AM, Al Holt wrote:
With the only difference between builds being the turns ratio of T1. Does that mean a higher current draw through the PA FET's during transmit? I would think it would mean a higher peak-to-peak voltage at the transformer's secondary and consequently higher output power as the chart in the instruction manual shows.I can't answer that part.? I was only pointing out that you probably have several devices and you have to be careful which wall wart you plug into which device for each of them.? This really isn't any different - except if you are planning to use a power supply from a mobile type rig (13.8V or so). ? -- Rob KB8RCO |
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Re: QDX's DC connector common to 9V and 12V builds a potential problem?
On Fri, Nov 12, 2021 at 11:21 AM, Bill Lamm wrote:
@ Rob KB8RCO...? please elaborate on why hard wiring to the PCB is a bad idea? I am considering Anderson power poles to a voltage regulator to the QDX so what ever I plug in is regulated to 9v..I didn't mean to imply hardwiring to the board was "not advised in my book", but that hardwiring a wall wart to the board was a bad idea. As discussed below that statement - "Change out the connector (since it is board mounted, this isn't as easy, but very doable)." ? -- Rob KB8RCO |
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Re: QDX firmware 1.01c with aids for debugging no-transmit-RF issues
This is great! On Fri, Nov 12, 2021 at 10:59 AM Arthur Paton <artpaton@...> wrote: Many thanks Hans, I think this will be a tremendous help for troubleshooting.? Well done. |
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Re: QDX's DC connector common to 9V and 12V builds a potential problem?
Mike and Rob thanks for your answers.
With the only difference between builds being the turns ratio of T1. Does that mean a higher current draw through the PA FET's during transmit? I would think it would mean a higher peak-to-peak voltage at the transformer's secondary and consequently higher output power as the chart in the instruction manual shows. The manual warns of possible overheating and failure of the PA transistors. Sounds like it might not mean an instant death to them but over an extended transmit period it would. --Al |
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Re: QDX's DC connector common to 9V and 12V builds a potential problem?
It's not a problem - - but at least tie a knot or two in the cable as a strain relief before putting it through the hole on the box.? ?I am debating on offboarding the whole +5v and 3.3v to all use switchers for battery use and would run the cables through the connector hole in doing that.? Of course that means a second box almost as big as the QDX but it can be located at the battery/supply side of the cable.? ? I hope to get this all done before Christmas.? Work and life is again in the way nearly 100%. Fred W0FMS? On Fri, Nov 12, 2021, 9:21 AM Bill Lamm <kd9mdl@...> wrote: @ Rob KB8RCO...? please elaborate on why hard wiring to the PCB is a bad idea? I am considering Anderson power poles to a voltage regulator to the QDX so what ever I plug in is regulated to 9v.. |
Mike Perry, WA4MP
Fred Spinner
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