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Re: QX off Frequency
If you have a QCX without the TCXO option, it can be a bit off frequency out of the box. The 27 MHz crystal for the Si5351A is an inexpensive microprocessor crystal and its frequency is not guaranteed to be highly accurate. It's usually a little bit above 27 MHz; the default setting of the reference frequency is actually 27.004000 MHz, 4 KHz above the nominal frequency. The firmware lets you set the actual reference frequency of the crystal in your QCX to get a more accurate frequency readout. (It uses that value to calculate the correct settings of the frequency synthesizer.) You can find the correct setting?in one of a few ways. If you have one of the QRP Labs GPS modules, you can use it to automatically set the frequency. If you have a frequency counter, you can measure the output frequency of your QCX, calculate the error, and then adjust the reference frequency accordingly. If you have a calibrated signal generator with a precise output, you can zero beat it with your QCX, and again calculate the error and adjust. You can set it in increments of 1 Hz, which is 0.037 ppm, a negligible error. (At 10 MHz, that would be a maximum error of 0.37 Hz. There are very few ham applications that require higher frequency accuracy than that. And it's going to depend somewhat on temperature in any case, so even if you set it to maximum accuracy on the test bench it might be a bit farther off when you operate the radio.) The procedure for setting the reference frequency is now in the QCX operating manual, which is separate from the QCX construction manual. it's on page 35 of the manual for firmware 1.07. The procedure for calibrating using the GPS module is on page 36. If you have the TCXO, the reference frequency needs to be set for 25.000000 MHz. The TCXO is specified as being accurate within 0.5 ppm, which would be an error of 5 Hz at 10 MHz. You can use the calibration procedure to set it more accurately if you wish, but most operators will find it unnecessary. If you do it, set it to 25 MHz manually first and THEN run the GPS calibration. Your reports from the RBN suggest that your QCX is about 50 ppm off from the default value. You didn't report whether your frequency is high or low. adjusting the reference frequency down 1.35 kHz (to 27.002650) if your frequency is high, or up 1.35 kHz (to 27.005350) if your frequency is low, should get you much closer. That amount of error is normal for inexpensive crystals; there is nothing wrong with your radio, and it's why the adjustment is there. A more tightly specified crystal might cost 10 times as much and require a price increase of the rig. It's also possible that the frequency accuracy of the RBN is less than perfect. Using GPS calibration is the best way to get the rig calibrated accurately if you have the GPS receiver for the QCX. On Fri, Nov 12, 2021 at 11:33 AM Martin DK3UW <m.sellschopp@...> wrote: I noted on my QCX, that the QRG is off from what RBN indicates. |
Re: QDX firmware 1.01c with aids for debugging no-transmit-RF issues
Is it safe to assume that these firmware updates are not incremental? I plan on starting my build soon and would like to just upload the latest. (I have had updates for other gear where you need to run thru them all with the oldest to the latest)
Thanks! 73 -Mike |
Re: QDX - No RF output, Tx line stays low
I installed firmware 1.01c, see the diagnostic flashing. ?One flash in PTT test, two in Tune in WSJT-X. ?Received signal level shows 80 on the bar graph, but now I don't decode anything. ?Went back to v1.01a, decoding again. ?Enough for one day!? 73, Ben. K0IKR |
Re: QDX - RX and TX stopped working on 80 meters only
Bob,
The one possibility might be the switching diodes are not on.? Can you verify that D1 and D4 are on and the other 4 off?? The way that I do it is to measure the voltage on the cathode (band side) of the diode.? The two close to zero are on, the other 4 should be above 3 volts.? If not then check the solder joints around the 80 meters low pass filter. 73 Evan AC9TU |
Re: QDX - RX and TX stopped working on 80 meters only
On Fri, Nov 12, 2021 at 04:45 PM, Bob Benedict, KD8CGH wrote:
On Tx the light blinks 3 times indicating the QDX thinks it's transmitting and the current draw increases slightly from .11 A to .26 A, but there is no measurable power output.Bob,? Is the QDX LED blinking with the newer firmware version 1_01c?? that makes a big difference. 73 Evan AC9TU |
QDX - RX and TX stopped working on 80 meters only
Info:
Windows 10 firmware 1.01a then 1.01c 12 v - 3:2 T1 Adjustable bench linear supply set at 12 volts,? 1.5 amps OCP setting, 3 A max from supply Rev 1 board built as designed (to the best of my knowledge) My QDX was operating on all bands and then abruptly quit operating on 80 meters. On RX switching from say 40 to 80 the watefall goes quiet and the signal strength drops to zero. Checking with another transceiver I see there is plenty of activity on 80 also, but nothing is getting through. Switching back to any other band the signals reappear. On Tx the light blinks 3 times indicating the QDX thinks it's transmitting and the current draw increases slightly from .11 A to .26 A, but there is no measurable power output. Previously I saw 4.9 watts out. I'm seeing 4.4 - 5.4 watts out on the other bands. Again on the other three bands it transmits and receives normally. Note - this happened while I was running with firmware 1.01a. Loading 1.01c didn't help. -- ? 73 ??? Bob? KD8CGH |
Re: QDX - No RF output, Tx line stays low
On Fri, Nov 12, 2021, at 04:10 PM, Ben Bangerter, K0IKR wrote:
This may lead me to get an RPi and display I suspect.Ben, I use one of my older flat-screen TVs with HDMI input for the Raspberry Pi (RPi) monitor and speakers.? The one that I have is 24" 1080p so nice high resolution for the RPi.? The sound is sent over the HDMI cable.? Suggest a Ras[berry Pi 4, though the 3 can do WSJT-X, just a little slower.? I bought a Cana Kit that included the heatsink as part of the case.? You do need to keep the processor cool, and this is the best non-fan version that I found.? You will need a USB mouse and keyboard as well. 73 Evan AC9TU |
Re: QDX - No RF output, Tx line stays low
Hans and Evan. Thank you for the quick replies. ?I had not seen that mention of a version 1.01c. ?I will do that. ?I have a Windows 10 laptop and a WinXP desktop. ?Yeah, I know - dated, but the best OS Microsoft ever put out. Used for film scanning and image processing. ?This may lead me to get an RPi and display I suspect. ?I was very cautious probing the QDX. ?These surface mount devices with small footprints make troubleshooting exceedingly difficult! ?And Evan: ?Oh to be 69 again. Ah, youth! ?I just turned 80.
73, Ben ?K0IKR |
Re: CAT Problem maybe?
¿ªÔÆÌåÓýBut any other rig does send RF when clicked on. WSJT-X returns a RED flag when used with QDX, which means the PTT hasn't switched, what is the use of the PTT test in WSJT-X if it doesn't turn GREEN ?
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73
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Ian G4GIR
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Re: CAT Problem maybe?
Ian,
Since there is no audio being sent to the radio, pressing the PTT button on the WSJT-X radio tab will put the QDX into a flashing once every second LED mode that indicates that the PTT has been received and it is ready to go but there is no audio at all. No power out the antenna port. 73 Evan AC9TU |
Re: Fw: [QRPLabs] CAT Problem maybe?
Hello Ian,
I assume that you are running the latest firmware: 1_01c?? If so, then the single flash every second would mean that the QDX is not getting an audio tone through the USB audio connection.? This is the correct response when testing the PTT line in the Radio Tab of WSJT-X.? To get a signal out, you would need to go to the main page and press the Tune button.? That sends an audio tone as well as setting the PTT signal. 73 Evan AC9TU |
Re: CAT Problem maybe?
On Fri, Nov 12, 2021 at 03:18 PM, Hans Summers wrote:
I can't check this now... But probably someone else can comment??Sending the TX or TQ1 command does not send out any RF, you just get the single flash every second as the latest firmware is designed to do.? There would be no audio. 73 Evan AC9TU |
Re: Chat Notifications
#chat-notice
The lights are on but no one is home! On Fri, Nov 12, 2021, 12:51 AM Joe <joseph.durnal@...> wrote: Web site says it is out of stock, can we place an order anyway? |
Re: Order status for a QDX
Alexander, thanks for the update! Roy WA0YMH On Fri, Nov 12, 2021, 8:38 AM Alexander R Archer N7SM via <flightsimalex=[email protected]> wrote: As promised, I'm returning to say mine shipped about 6 hours ago. Order 50314, from US stock. Yours shouldn't be too far behind! Good luck. |
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. |
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. |
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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