Solar inverter noise

[VK3ZYZ]

Ray and Josh came around here and had a little bit of a play to try and track down the noise from my solar inverters.
I've just fixed (I hope) the IC22S and put it back into service.
It has an S meter so the noise level can be monitored.
Here is the repeater at the moment..

It is quite ok. But have a look at a little higher in the band...

This interference frequency varies with the inverter power. At the moment, the inverters are running at 3.2KW and 2.8KW. It appears I have a crook panel or two as they should be about the same.
AHHHHH! The IC22S just dropped out of lock again so I did not fix it!
A mod I did was to extend the S meter signal out so I can organize to log it. And if the software was still working, there is a capability to read the inverters too but I do not know how to do that.

Back to the shed with the IC22S!!!!

 

[VK3ZYZ]

Here are my inverters with the Ferrite clip-ons Ray installed. I've got to get the IC22S running again so the S meter can be used to see if adding Ferrite makes any difference.

 

[VK3ZYZ]

I've run a series of S meter tests.
Here is the code.

#define Version "IC22S_Smeter"

#define S_Meter A7    // S_Meter Input
int reading;
void setup() {
Serial.begin(9600);
}

void loop() {
  reading=(analogRead(S_Meter));
  Serial.println(reading);
  delay(10000);

}

Around 5PM, this is the listening to the Mt Wombat 2M repeater. You can see when it is triggered. 1 sample per second.

Here is the noise on 146.750 around the same time.

Just to show the noise is on specific frequencies, depending on how the inverters are running, you can see the drop when changed from 146.750 to 146.650Mhz.

And here it is on 146.650 towards the end of the day. The inverters finally shut down at around 450 mark. 1 sample every 10 seconds.

A good use of the Arduino Nano screw terminals!

 

[VK3ZYZ]

I've altered the code to read at 3 mins intervals so I can fit a full day into the 500 reading spaces.
Also, every hour, there is a pulse to mark the time.

#define Version "IC22S_Smeter"
#define S_Meter A7    // S_Meter Input
int reading;
int hour_counter= 0;
void setup() {
Serial.begin(9600);
Serial.println(245);    // mark hour
}
void loop() {
  reading=(analogRead(S_Meter));
  Serial.println(reading);
  hour_counter ++;
    if (hour_counter == 20)
  { Serial.println(245);    // mark hour
    hour_counter = 0;       // reset it.
  }
  delay(180000);  // 3 mins.
}

Note, at the end of the graph, it shows me talking to VK3JRA. Hence the thick bar.

 

[VK3ZYZ]

Here is today's scan. The inverters have closed down. You can see how the interference changes during the day.
When the 36 Ferrite clip-ons get here, I'll load the leads up and see if the scan changes.

 

[VK3ZYZ]

I was interested to catch the inverters starting up.
Here is a plot at 10 second sample intervals.

 

[VK3ZYZ]

Latest update. The clip on coils arrived so they are installed and no noticeable improvement has been notices.
I may try to get a good Earth to the inverters.

 

[BillC]

Pretty tough that inverter noise, can you track around with a sniffer to check for higher radiation zones etc , I am fairly sure if one needed a wide band noise source you would build an inverter. However it looks as though you have a nice data logging system there now Denys? . Cheers.