在 2024年8月30日，13:30，atkinsonr via groups.io <atkinsonr@...> 写道：

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Hello

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I'm new to amateur radio and this is my first radio build.

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I have assembled the main board and the 40m LPF, but all 5 LEDs remain lit with the LPF board installed.

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What have I tried?

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At first I thought it might be the microcontroller board;

?? a) so I tried the 3v3 and 5v tests at R1 and U2(Vin) respectively, all good.

?? b) I reflashed the microcontroller with the hex file (it flashed fine but didn't fix the issue)

?? c) I bought a new arduino nano, flashed that - still all LEDs are on.

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I don't have a spectrum analyser, only a DSO, a multimeter that measures Hz and an ATU-100. Connecting the ADX-S V2 to the ATU and a dummy load, I see no power measured by the ATU.

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Holding down SW1 and SW2 does not make the TX LED flash.

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Two LEDs are lit on the Nano (pwr and L)

Ther BFO LED is not lit.

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Advice on where to probe, what to look for would be most appreciated. I have a DSO and multimeter.

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73

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Rich VK2 LTC

在 2024年8月30日，13:35，atkinsonr via groups.io <atkinsonr@...> 写道：

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Confirmed. 1k resistor on this one. LPF board is populated according to this schema: /g/crkits/files/ADX-S/V2/Schematic_ADX-S%20V2%20and%20BAND%20FILTER_2024-07-13.pdf

Thanks Bernd and Adam for your help with this.

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The photo is helpful, thank you. I belive my LPF is correct and have attached a photo.

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Some measurements:

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With the LPF off the mainboard, I measure 1kΩ across it's 12v - GND pins.

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I desoldered R18 and tested it out of circuit, it measures 1kΩ.

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Whilst poking around I shorted something and blew the voltage regulator on the the Nano. Lucky I bought a second Nano!

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Should the A2 pin on the Nano be 2.5v with the 40 LFP installed? I'm reading zero volts at the A2 pin.

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I measure 1kΩ between the A2 pin and ground when the LPF is in circuit, 4MΩ when it's not.

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I measure 0v at the A2 pin with the LPF installed, and 1.6v with the LPF removed.

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Hi Adam

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R18 is indeed 1k, but I measure 0v at the A2 pin with the LPF installed, and 1.6v with the LPF removed.

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I'm not sure what to look for next.

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Rich

Good morning Bernd

Thank you very much for the handholding.

I found that the high resistance (about 4 Mohm) was between the A2 pin and the nearest side of R18. I reflowed the solder through these joints, but it didn't make any difference - so I bridged them using a piece of resistor leg - that fixed it. The Ardunio now recognises the LPF board!

I resoldered the clock module to the main board, and now it seems to behave unpredictably.

I pressed the TX button while connected to a dummy load via an ATU, and saw 3.3 watts of output. However, the next time I pressed TX - the TX LED didn't light and there was no TX power.

I power cycled the board, and saw a fast-flashing TX LED.

Power-cycled again. This time, instead of the band 1 LED, the band 2 and 4 LEDs were lit.

Power-cycle again, Bands 1,2 and 3 were lit.

Power-cycle again, Band 1 lights correctly - but the switches don't do anything.

I appreciate that this is a good quality kit, and I'm a poor electronics engineer, and once again your guidance is very much appreciated.

PS: It wasn't a typo - I thought that the LPF would have AC across it, my mistake - it's about 2.5 VDC.

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Rich Atkinson

+61 425 261 410

On Sat, 31 Aug 2024 at 17:52, Bernd DL3BLA via <b.langner=[email protected]> wrote:

[Edited Message Follows]

Hello Rich
Why don't you make a simple resistance measurement without
voltage. To do this, remove the Arduino LPF plugged. Then measure against ground at A2 should be ~1Kohm, then ground against 5V Arduino
should be ~ 2Kohm.
If the values are correct, the board is ok and R18 and the resistor on the LPF are correctly mounted.

If the values are ok we have to look further?

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Rich wrote: I have about 11.2v AC between 12v and GND pins on the LPF.

Rich you have to measure in the DC range or was that a typo

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Bernd

Hi Adam

Yes, by clock module I mean the purple board.

Reflashing the nano made it work again, I was able to TX twice, then it started misbehaving again (and presumably needs reprogramming again). Do you know why this would be?

PS: I can't see any visible reason why A2 and R18 weren't properly connected, I expect it is my soldering rather than a defect in the board.

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Rich Atkinson

On Sun, 1 Sept 2024 at 11:40, Adam Rong via <rongxh=[email protected]> wrote:

Hi Rich,

Good to know the LPF detection fix. Is it a PCB trace crack or something similar?

What is the clock module, you mean the whole purple board or just the green TCXOM module?

Can you re-program the Nano to check if it works again?

Thanks,

Adam

在 2024/9/1 9:15, Rich Atkinson via 写道:

Good morning Bernd

Thank you very much for the handholding.

I found that the high resistance (about 4 Mohm) was between the A2 pin and the nearest side of R18. I reflowed the solder through these joints, but it didn't make any difference - so I bridged them using a piece of resistor leg - that fixed it. The Ardunio now recognises the LPF board!

I resoldered the clock module to the main board, and now it seems to behave unpredictably.

I pressed the TX button while connected to a dummy load via an ATU, and saw 3.3 watts of output. However, the next time I pressed TX - the TX LED didn't light and there was no TX power.

I power cycled the board, and saw a fast-flashing TX LED.

Power-cycled again. This time, instead of the band 1 LED, the band 2 and 4 LEDs were lit.

Power-cycle again, Bands 1,2 and 3 were lit.

Power-cycle again, Band 1 lights correctly - but the switches don't do anything.

I appreciate that this is a good quality kit, and I'm a poor electronics engineer, and once again your guidance is very much appreciated.

PS: It wasn't a typo - I thought that the LPF would have AC across it, my mistake - it's about 2.5 VDC.

—

Rich Atkinson

+61 425 261 410

On Sat, 31 Aug 2024 at 17:52, Bernd DL3BLA via <b.langner=[email protected]> wrote:

[Edited Message Follows]

Hello Rich
Why don't you make a simple resistance measurement without
voltage. To do this, remove the Arduino LPF plugged. Then measure against ground at A2 should be ~1Kohm, then ground against 5V Arduino
should be ~ 2Kohm.
If the values are correct, the board is ok and R18 and the resistor on the LPF are correctly mounted.

If the values are ok we have to look further?

?

Rich wrote: I have about 11.2v AC between 12v and GND pins on the LPF.

Rich you have to measure in the DC range or was that a typo

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Bernd

Hi Adam

With the dummy load and no ATU, I can transmit over and over again without messing up the MCU code.

thanks for your help

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Rich Atkinson

On Sun, 1 Sept 2024 at 12:25, Adam Rong via <rongxh=[email protected]> wrote:

Hi Rich,

ATU is not recommended. A dummy load is good enough to do the TX test. If ATU is not well tuned, it will return high RF voltage, and it is the possible reason to mess up the MCU code. Please make sure your C25 near R18 is well connected to A2 pin, as it is a protection.

Thanks,

Adam

在 2024/9/1 10:17, Rich Atkinson via 写道:

Hi Adam

Yes, by clock module I mean the purple board.

Reflashing the nano made it work again, I was able to TX twice, then it started misbehaving again (and presumably needs reprogramming again). Do you know why this would be?

PS: I can't see any visible reason why A2 and R18 weren't properly connected, I expect it is my soldering rather than a defect in the board.

—

Rich Atkinson

On Sun, 1 Sept 2024 at 11:40, Adam Rong via <rongxh=[email protected]> wrote:

Hi Rich,

Good to know the LPF detection fix. Is it a PCB trace crack or something similar?

What is the clock module, you mean the whole purple board or just the green TCXOM module?

Can you re-program the Nano to check if it works again?

Thanks,

Adam

在 2024/9/1 9:15, Rich Atkinson via 写道:

Good morning Bernd

Thank you very much for the handholding.

I found that the high resistance (about 4 Mohm) was between the A2 pin and the nearest side of R18. I reflowed the solder through these joints, but it didn't make any difference - so I bridged them using a piece of resistor leg - that fixed it. The Ardunio now recognises the LPF board!

I resoldered the clock module to the main board, and now it seems to behave unpredictably.

I pressed the TX button while connected to a dummy load via an ATU, and saw 3.3 watts of output. However, the next time I pressed TX - the TX LED didn't light and there was no TX power.

I power cycled the board, and saw a fast-flashing TX LED.

Power-cycled again. This time, instead of the band 1 LED, the band 2 and 4 LEDs were lit.

Power-cycle again, Bands 1,2 and 3 were lit.

Power-cycle again, Band 1 lights correctly - but the switches don't do anything.

I appreciate that this is a good quality kit, and I'm a poor electronics engineer, and once again your guidance is very much appreciated.

PS: It wasn't a typo - I thought that the LPF would have AC across it, my mistake - it's about 2.5 VDC.

—

Rich Atkinson

+61 425 261 410

On Sat, 31 Aug 2024 at 17:52, Bernd DL3BLA via <b.langner=[email protected]> wrote:

[Edited Message Follows]

Hello Rich
Why don't you make a simple resistance measurement without
voltage. To do this, remove the Arduino LPF plugged. Then measure against ground at A2 should be ~1Kohm, then ground against 5V Arduino
should be ~ 2Kohm.
If the values are correct, the board is ok and R18 and the resistor on the LPF are correctly mounted.

If the values are ok we have to look further?

?

Rich wrote: I have about 11.2v AC between 12v and GND pins on the LPF.

Rich you have to measure in the DC range or was that a typo

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Bernd