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I have a QDX Rev 3,? when I construct it I use firmware v1_05 and everything is OK. Yestoday I upgrade firmware to v1_10 and do some audio filter sweep and RF filter sweep(with dummy load), the result looks very terreble (see the image below). I do a factory reset, but the result is the same.
Then I try downgrade firmware to v1_06, nothing get better. Then downgrade to v1_05, suddenly everything is OK and the beautiful sweep curver come back. I have check "Configuretion" and "Band configuration", they are the same. So I was confused, what's wrong with it? Any suggestion? Thanks
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Today I use firmware v1_10 do some test again. I use a?oscilloscope watching R41 and R40(CLK0 and CLK1), and found something strange.?In theory, CLK0 and CLK1 should have the same frequency but be 90 degrees phase different. But when doing audio filter sweep what I saw is like this:
The yellow channel is CLK0 and green channel is CLK1. From this images we can see that frequency and phase are totaly wrong. Then I return to firmware v1_05, everything return fine. So I think it's probably a firmware incompatibility issue.?But the strange thing is, am I the only one who has this problem?
Here is my QDX PCB's photo:
Hope who use the same version PCB can give me some feedback about firmware v1_10. Thanks
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Lynx,
Have you tried returning to 1_05 to verify it is a software issue?? It could be that the Si5351 has failed.? If you return to 1_05, please post a screenshot of the oscilloscope trace.??
Of note is that the 60-meter traces show that the green trace is missing, yet there is a decent discrimination of the sideband.? This could point to a measurement issue.
Suggests only.
73
Evan
AC9TU
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On 19/01/2024 13:27, Lynx BG7JAF wrote: the strange thing is, am I the only one who has this problem? I've just checked my V3..Firmware 1.10. I guess I fixed the audio short if that was relevant It has a clock buffer like the V4, .I do not think that will make a difference. I did audio and RF scans that look good so I have no problem. 73 Alan G4ZFQ
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On Fri, Jan 19, 2024 at 02:26 PM, Evan Hand wrote:
Lynx,
Have you tried returning to 1_05 to verify it is a software issue?? It could be that the Si5351 has failed.? If you return to 1_05, please post a screenshot of the oscilloscope trace.??
Hi Evan, I just ran another test. Here is v1_05's trace: The results appears to be tolerable. Then, I upgrade the firmware to v1_10 again, the results are not surprisingly went wrong. The error seems random. I pick a few screenshot here: ? ? ? ? ? ? ? ? ? ?after doing 40m audio sweep, both frequency and phase are wrong.
? ? ? ? ? ? ? ? ? ?frequency and phase looks ok, but test performence is bad? ? ? ? ? after doing 20m audio sweep then do 40m sweep again, both freqency and phase are wrong.
So I think maybe the new firmware is incompatable with my hardware. Luckly I still can use v1_05, maybe I will try replace si5351a latter and see what happen. 73 Lynx BG7JAF
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On Fri, Jan 19, 2024 at 04:39 PM, Alan G4ZFQ wrote:
On 19/01/2024 13:27, Lynx BG7JAF wrote:
the strange thing is, am I the only one who has this problem?
I've just checked my V3..Firmware 1.10. I guess I fixed the audio short
if that was relevant It has a clock buffer like the V4, .I do not think
that will make a difference.
I did audio and RF scans that look good so I have no problem.
73 Alan G4ZFQ
Hi Alan, Thanks for your feedback, so I know that the new firmware version can work on v3 hardware. I will try replace si5351a and do a new test. 73 Lynx BG7JAF
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Lynx,
Have you tried downloading another copy of the firmware?? Maybe the copy you have is corrupt?? Not likely, but a possibility.
73
Evan
AC9TU
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On Sat, Jan 20, 2024 at 12:07 PM, Evan Hand wrote:
Lynx,
Have you tried downloading another copy of the firmware?? Maybe the copy you have is corrupt?? Not likely, but a possibility.
Yes, I have also try v1_06 and v1_09, they also not work correct. But this two version I have not test the CLK0 and CLK1 waveform. v1_10 firmware I have downloaded two times and they are the same. 73 Lynx BG7JAF
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Lunx,
I guess we will need to wait for a response from Hans.? I am out of ideas.
73
Evan
AC9TU
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Lynx,
Have yu tried a factory reset to clear the EEPROM?
73
Evan
AC9TU
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Lynx,
The reset would be after loading the new version.
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On Sat, Jan 20, 2024 at 05:38 PM, Evan Hand wrote:
Lynx,
The reset would be after loading the new version.
Hi Evan, I have do factory reset after reflash new firmware, but the result is the same. 73 Lynx BG7JAF
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Lynx,
You can post a question to Hans, as I am out of ideas.? Hans is on vacation until Friday.??
73
Evan
AC9TU
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Lynx,
Jeff Moore W1NC repairs QRP-Labs radios for others.? He is recognized as one of the best repair people in the group.? He ran into a weird problem on a QMX related to the frequency that replacing the hardware could not solve.? The QMX has a very similar architecture to the QDX.? The problem he found was related to the Si5351 synthesizer chip not being programmed correctly on startup.? He traced it to the EEPROM, causing issues with the I2C communication shared with the Si5351.
I suggest that you try replacing the EEPROM to see if that helps.
73
Evan
AC9TU
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Evan,
Thanks for your useful information, I will replace the EEPROM chip and try again.? I just order the chip,? it will be ready for testing tomorrow night.
73
Lynx
BG7JAF
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Evan,
Today I replace the EEPROM, but everythings are the same. Then I replace si5351a,? bingo, it worked correct now!
Maybe the communication speed have changed after firmware v1_05 and the old chip cann't handle it correctly?
Anyway, I have fix this rig up, I am happy this moment. Thanks for your help.
73
Lynx
BG7JAF
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Lynx,
Thank you for the update.? I am glad you were able to repair your QDX.? It seems like the most recent Si5351a chips are not as resilient as prior chips.? We seem to have more of them recently.
Have fun with your QDX!
73
Evan
AC9TY
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