<![CDATA[ARCHIVE: Australian Ham Radio Discussion Forum ( AHRDF ) - *** READ-ONLY *** - EMC, Interference]]> https://www.ahrdf.net/forum/ Fri, 08 May 2026 03:07:10 +0000 MyBB <![CDATA[Domestic PV solar inverter noise]]> https://www.ahrdf.net/forum/showthread.php?tid=1378 Wed, 31 Jan 2024 01:41:59 +0000 VK3LU]]> https://www.ahrdf.net/forum/showthread.php?tid=1378 I am considering having a new system installed by Solarhart, so any feedback would be very welcome regarding their inverters.

Nev]]> I am considering having a new system installed by Solarhart, so any feedback would be very welcome regarding their inverters.

Nev]]> <![CDATA[Honda EU22i - high EMI]]> https://www.ahrdf.net/forum/showthread.php?tid=1285 Thu, 16 Mar 2023 09:30:11 +0000 VK3BA]]> https://www.ahrdf.net/forum/showthread.php?tid=1285 I recall years ago on the VK-Logger Forums a discussion around the Honda EU20i vs other generators and how quiet the Honda EU20i was in regards to EMI. Every man and his dog running a portable field day effort most likely has a Honda EU20i along for the ride to run the show.

A mate of mine has recently purchased a Honda EU22i for his HF portable effort, as I said the EU20i was quiet, so should be the EU22i... well, what a shock it's been... it's terrible... what I forgot was that the EU20i runs a carburetor and I think the EU22i runs fuel injection. So we think the noise isn't coming from the inverter but perhaps the ECU fuel injection. We're going to do further measurements in coming days, but I wonder has anyone else had similar issues with the Honda EU22i, especially running a linear power supply into a HF rig???

The Honda EU20i were well known for their low or nil EMI emissions... but the Honda EU22i has become such a terrible surprise...


Cheers,]]> I recall years ago on the VK-Logger Forums a discussion around the Honda EU20i vs other generators and how quiet the Honda EU20i was in regards to EMI. Every man and his dog running a portable field day effort most likely has a Honda EU20i along for the ride to run the show.

A mate of mine has recently purchased a Honda EU22i for his HF portable effort, as I said the EU20i was quiet, so should be the EU22i... well, what a shock it's been... it's terrible... what I forgot was that the EU20i runs a carburetor and I think the EU22i runs fuel injection. So we think the noise isn't coming from the inverter but perhaps the ECU fuel injection. We're going to do further measurements in coming days, but I wonder has anyone else had similar issues with the Honda EU22i, especially running a linear power supply into a HF rig???

The Honda EU20i were well known for their low or nil EMI emissions... but the Honda EU22i has become such a terrible surprise...


Cheers,]]> <![CDATA[LED downlights...RFI problems?]]> https://www.ahrdf.net/forum/showthread.php?tid=1153 Mon, 07 Feb 2022 22:28:44 +0000 VK3LU]]> https://www.ahrdf.net/forum/showthread.php?tid=1153 I am going to install LED downlights in my house and am wondering if there are any brands to avoid regarding RFI.
Has anyone had any experience with them?

Nev]]> I am going to install LED downlights in my house and am wondering if there are any brands to avoid regarding RFI.
Has anyone had any experience with them?

Nev]]> <![CDATA[Recomended RF quiet Solar Inverter]]> https://www.ahrdf.net/forum/showthread.php?tid=1126 Fri, 17 Dec 2021 13:42:12 +0000 VK6TU]]> https://www.ahrdf.net/forum/showthread.php?tid=1126 inverters should I avoid with regard to RF interference or better still which are the preferred models.

I will be installing a 5kw 3 phase system.

73 from Michael
VK6TU]]> inverters should I avoid with regard to RF interference or better still which are the preferred models.

I will be installing a 5kw 3 phase system.

73 from Michael
VK6TU]]> <![CDATA[Wideband noise south-east Qld this week]]> https://www.ahrdf.net/forum/showthread.php?tid=1103 Tue, 16 Nov 2021 23:22:11 +0000 VK4KD]]> https://www.ahrdf.net/forum/showthread.php?tid=1103
My 2m mobile rig was being smashed all around the 146-147MHz mark at Rothwell around 2100 on Monday, and then again last night between 2000 and 2100 at Eatons Hill.

I've heard unconfirmed reports of the noise extending up into 70cm (!) and down to 20m (!!) and as far afield as the Sunshine Coast (!!!)

So far it seems to have mainly been a problem after dark. It just sounds like white-noise, I can't detect any real signal in it.

I managed to catch a very solid and *wide* (around 50KHz) spike about 30dB above the noise floor here, centred right on 146.500, so I grabbed a yagi and went DFing.

Only had limited time available, but I could see 45dB above the noise floor at a bearing of around 240 (true) from Eatons Hill, and about the same bearing from Clear Mountain, which would roughly place it on a line out through Marburg towards Warwick. My VK3YNG sniffer was showing a peak strength of "4", which means it's detecting enough signal to break squelch with 60dB of attenuation in the way.

Whatever it is, it's strong, and it's pervasive.

Anyone else able to get a direction on it?]]>
My 2m mobile rig was being smashed all around the 146-147MHz mark at Rothwell around 2100 on Monday, and then again last night between 2000 and 2100 at Eatons Hill.

I've heard unconfirmed reports of the noise extending up into 70cm (!) and down to 20m (!!) and as far afield as the Sunshine Coast (!!!)

So far it seems to have mainly been a problem after dark. It just sounds like white-noise, I can't detect any real signal in it.

I managed to catch a very solid and *wide* (around 50KHz) spike about 30dB above the noise floor here, centred right on 146.500, so I grabbed a yagi and went DFing.

Only had limited time available, but I could see 45dB above the noise floor at a bearing of around 240 (true) from Eatons Hill, and about the same bearing from Clear Mountain, which would roughly place it on a line out through Marburg towards Warwick. My VK3YNG sniffer was showing a peak strength of "4", which means it's detecting enough signal to break squelch with 60dB of attenuation in the way.

Whatever it is, it's strong, and it's pervasive.

Anyone else able to get a direction on it?]]> <![CDATA[LED lighting EMC/RFI Report]]> https://www.ahrdf.net/forum/showthread.php?tid=1054 Thu, 08 Jul 2021 04:40:10 +0000 VK2ZRH]]> https://www.ahrdf.net/forum/showthread.php?tid=1054 conducted emissions from household LED lamps reveals that there has been little improvement over the past decade, with one exception.

Measurements of conducted emissions were made across the frequency range from 150 kHz to 30 MHz using a standardised set up, which is detailed in the article.

The author, Ken Wyatt WA6TTY, is a senior EMC engineer heading his own technical consulting company, a senior member of the IEEE, and a long-time member of the EMC Society.

Check out the article here: Comparing conducted emissions from LED lamps
www.edn.com/comparing-conducted-emissions-from-led-lamps/]]> conducted emissions from household LED lamps reveals that there has been little improvement over the past decade, with one exception.

Measurements of conducted emissions were made across the frequency range from 150 kHz to 30 MHz using a standardised set up, which is detailed in the article.

The author, Ken Wyatt WA6TTY, is a senior EMC engineer heading his own technical consulting company, a senior member of the IEEE, and a long-time member of the EMC Society.

Check out the article here: Comparing conducted emissions from LED lamps
www.edn.com/comparing-conducted-emissions-from-led-lamps/]]> <![CDATA[UPS with no RF noise?]]> https://www.ahrdf.net/forum/showthread.php?tid=1032 Wed, 24 Mar 2021 04:14:03 +0000 VK3RX]]> https://www.ahrdf.net/forum/showthread.php?tid=1032
Both generate S2-3 and higher noise across the HF spectrum. I've tried clip-on ferrites and toroids and much messing around but no change.

Anyone recommend a UPS for this type of use that doesn't generate crud??

Reading around it seems the pure sinewave type might be the type to go for.

650VA/390W Line Interactive UPS with LCD and USB]]>
Both generate S2-3 and higher noise across the HF spectrum. I've tried clip-on ferrites and toroids and much messing around but no change.

Anyone recommend a UPS for this type of use that doesn't generate crud??

Reading around it seems the pure sinewave type might be the type to go for.

650VA/390W Line Interactive UPS with LCD and USB]]> <![CDATA[Downlight QRM questions]]> https://www.ahrdf.net/forum/showthread.php?tid=988 Sun, 13 Sep 2020 00:42:01 +0000 VK2KRR]]> https://www.ahrdf.net/forum/showthread.php?tid=988
I recall hearing that down lights used to cause QRM for some people, is that correct?

If so, is this still the case with new lights these days? or has the manufacturing standards been tightened up to prevent RFI?

Any particular brands that might be better than others etc?

Thank you.]]>
I recall hearing that down lights used to cause QRM for some people, is that correct?

If so, is this still the case with new lights these days? or has the manufacturing standards been tightened up to prevent RFI?

Any particular brands that might be better than others etc?

Thank you.]]> <![CDATA[Shielded Ethernet cable?]]> https://www.ahrdf.net/forum/showthread.php?tid=963 Tue, 09 Jun 2020 22:07:55 +0000 VK2KRR]]> https://www.ahrdf.net/forum/showthread.php?tid=963
Thanks]]>
Thanks]]> <![CDATA[Tigo TS-4 Optimisers First Hand Advice?]]> https://www.ahrdf.net/forum/showthread.php?tid=962 Thu, 04 Jun 2020 06:25:33 +0000 VK1JA]]> https://www.ahrdf.net/forum/showthread.php?tid=962 Hi all,

Talking home (grid tie) solar electricity setups.

We have a vertical band of shade that moves across our panels through the day which is reducing the string voltage arcoss the whole array.

Google searches revealed that optimisers installed to each panel will help, and essentially bypass the shaded panel - the optimisers work much better compared to the bypass diodes already in the panel.

Google also revealed that the first version of the SolarEdge optimisers (different brand) generated broadband RFI, but they fixed the problem in the newer models. The recommended optimisers these days are the Tigo brand, TS-4 model which I haven't found any complaints about so far.

I've emailed Tigo asking if they know of any problems with regards to RFI, but I was wondering if anyone has any first hand experience with the Tigo Optimisers?

I'm considering having one optimiser installed and see if that causes and RFI, then proceeding from there.

Thanks

Jayson]]> Hi all,

Talking home (grid tie) solar electricity setups.

We have a vertical band of shade that moves across our panels through the day which is reducing the string voltage arcoss the whole array.

Google searches revealed that optimisers installed to each panel will help, and essentially bypass the shaded panel - the optimisers work much better compared to the bypass diodes already in the panel.

Google also revealed that the first version of the SolarEdge optimisers (different brand) generated broadband RFI, but they fixed the problem in the newer models. The recommended optimisers these days are the Tigo brand, TS-4 model which I haven't found any complaints about so far.

I've emailed Tigo asking if they know of any problems with regards to RFI, but I was wondering if anyone has any first hand experience with the Tigo Optimisers?

I'm considering having one optimiser installed and see if that causes and RFI, then proceeding from there.

Thanks

Jayson]]> <![CDATA[Fridge RFI ??]]> https://www.ahrdf.net/forum/showthread.php?tid=917 Wed, 05 Feb 2020 06:38:31 +0000 VK4CCV]]> https://www.ahrdf.net/forum/showthread.php?tid=917
I have come across a situation that I have never heard of.

We bought a new fridge about 6 months ago.

For a while now, not sure when this started, I guess at the same time we put the fridge put in, but anyway, I always had the noise on 20M and have been trying to trace the source down for a while, but never could find the source.

Last week I had a hunch and pulled the plug on the fridge - 20M instantly goes quiet.

OK, I now how to get rid of RFI from wall warts and the like, but unsure where I need to start with the Fridge.

Any suggestions will be greatly appreciated.

Cheers

VK4CCV]]>
I have come across a situation that I have never heard of.

We bought a new fridge about 6 months ago.

For a while now, not sure when this started, I guess at the same time we put the fridge put in, but anyway, I always had the noise on 20M and have been trying to trace the source down for a while, but never could find the source.

Last week I had a hunch and pulled the plug on the fridge - 20M instantly goes quiet.

OK, I now how to get rid of RFI from wall warts and the like, but unsure where I need to start with the Fridge.

Any suggestions will be greatly appreciated.

Cheers

VK4CCV]]> <![CDATA[NBN interference]]> https://www.ahrdf.net/forum/showthread.php?tid=910 Sat, 18 Jan 2020 02:48:28 +0000 VK3RX]]> https://www.ahrdf.net/forum/showthread.php?tid=910
Anyone experienced noise related to this technology?]]>
Anyone experienced noise related to this technology?]]> <![CDATA[New interference source across the road]]> https://www.ahrdf.net/forum/showthread.php?tid=906 Tue, 14 Jan 2020 04:40:33 +0000 VK5TM]]> https://www.ahrdf.net/forum/showthread.php?tid=906

We got the development notification from the council yesterday and have 10 days to lodge an objection, which is way less time than needed to do a proper RF baseline interference study (@ $3500 plus the cost of the report, which I don't currently have just lying around at the moment).

So, any other suggestions as to what I can do that may prove useful as proof of what the RF baseline was before they build this thing?

As far as using the "It interferes with my broadcast TV/Radio reception" line, the ACMA classifies this area as a "Fortuitous reception area", so unlikely to be of any use in any possible dispute.]]>

We got the development notification from the council yesterday and have 10 days to lodge an objection, which is way less time than needed to do a proper RF baseline interference study (@ $3500 plus the cost of the report, which I don't currently have just lying around at the moment).

So, any other suggestions as to what I can do that may prove useful as proof of what the RF baseline was before they build this thing?

As far as using the "It interferes with my broadcast TV/Radio reception" line, the ACMA classifies this area as a "Fortuitous reception area", so unlikely to be of any use in any possible dispute.]]> <![CDATA[2.4 GHz Interference to WiFi]]> https://www.ahrdf.net/forum/showthread.php?tid=805 Wed, 29 May 2019 09:21:09 +0000 VK2CSW]]> https://www.ahrdf.net/forum/showthread.php?tid=805
Amongst all of the trials and tribulations of trying to get NBNCo to come and look at the interference their equipment is causing a new issue appeared.

The Ping times would blow out, Down and Upload speeds would drop into the sub 0.5 Mbps range and connections would start to time out.  With everything else RSP/NBN related this issue caused much frustration and swearing.  Huh

The WiFi sniffer showed that the signal strength was OK, few overlapping other services, so all good it seemed.  I ran a 20m ethernet cable to the router and presto - performance was back.  Unplugged and down it went again.

After much searching and hair pulling (okay that's a lie - there's none left Tongue  ) it turns out that the wireless keyboard was wiping out the 2.4 GHz spectrum.  As soon as the batteries came out of it the WiFi started to play nicely.  Back to a wired keyboard for now.

So for future reference does anyone know of a way of looking at the 2.4 and 5 GHz spectrum for just such interference - without spending thousands on a fancy Spec An?

Would any of the SDR type dongles get to those bands and what software would be needed?]]>
Amongst all of the trials and tribulations of trying to get NBNCo to come and look at the interference their equipment is causing a new issue appeared.

The Ping times would blow out, Down and Upload speeds would drop into the sub 0.5 Mbps range and connections would start to time out.  With everything else RSP/NBN related this issue caused much frustration and swearing.  Huh

The WiFi sniffer showed that the signal strength was OK, few overlapping other services, so all good it seemed.  I ran a 20m ethernet cable to the router and presto - performance was back.  Unplugged and down it went again.

After much searching and hair pulling (okay that's a lie - there's none left Tongue  ) it turns out that the wireless keyboard was wiping out the 2.4 GHz spectrum.  As soon as the batteries came out of it the WiFi started to play nicely.  Back to a wired keyboard for now.

So for future reference does anyone know of a way of looking at the 2.4 and 5 GHz spectrum for just such interference - without spending thousands on a fancy Spec An?

Would any of the SDR type dongles get to those bands and what software would be needed?]]> <![CDATA[Chinese CODAN intruding into the 40m band]]> https://www.ahrdf.net/forum/showthread.php?tid=767 Wed, 27 Mar 2019 09:13:57 +0000 VK3RX]]> https://www.ahrdf.net/forum/showthread.php?tid=767
Quote:From Ary Boender in the UDXF- the list of logs is too long to post here, but here's the test. Any transcription errors are mine...

Since mid 2016 I logged CODAN selcalls on 7, 8, 11 and 13 MHz. Until a week ago I didn't know who they are. Australian State Emergency Services was suggested but there are too many stations and they are also transmitting 24/7. That doesn't fit the SES activities. Besides that SES and affiliated service do not use these frequencies. So, if it isn't the SES, what is it???

It appears to be a HF Vehicle Tracking System. The syatem is used by companies in various countries, but the specific traffic that I heard all come from one place: the Spratley Islands in the South China Sea. China is building artificial islands in the Fiery Cross Reef. The Chinese started their activities in 2015. The first transmissions from that area were noticed in early 2016. The tracking system uses CODAN equipment that sends selcalls to base stations. The base stations use the received data to track the ships, barges and cars used for the building activities. Sometimes GPS data is mentioned in the CODAN messages, but so far I have no idea how to read it.

Voice traffic has been heard in Mandarin following CODAN calls. These are actual calls, not the tracking devices. They are answered by the reverted tones sent by the receiver's CODAN radio to acknowledge the receipt of the signal.

Base stations IDs include: 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 1188, 6363, 6969, 7474, 7979, 9898, etc. Note the combinations: either XXXX or XXYY or XYXY. Easy to recognize. These IDs are in the "TO" field.

Frequencies in USB. The center frequency is 1785Hz higher.

7103, 7106, 7109, 7112, 7121, 7124, 7127, 7130, 7133, 7139, 7142, 7145, 7148, 7157, 7160, 7918, 7921, 7933, 7936, 7938, 8003, 8006, 8009, 8012, 8015, 8021, 8024, 8027, 8030, 8033, 8041, 8066, 8072, 8075, 8078, 8596, 9047, 9090, 11149, 11159, 11163, 11168, 13431, 13452 kHz and maybe more.

The Chinese are intruding the 7MHz HAM bands with this service.

Examples of GPS data:
ESN 117117
ESN 117255
]]>
Quote:From Ary Boender in the UDXF- the list of logs is too long to post here, but here's the test. Any transcription errors are mine...

Since mid 2016 I logged CODAN selcalls on 7, 8, 11 and 13 MHz. Until a week ago I didn't know who they are. Australian State Emergency Services was suggested but there are too many stations and they are also transmitting 24/7. That doesn't fit the SES activities. Besides that SES and affiliated service do not use these frequencies. So, if it isn't the SES, what is it???

It appears to be a HF Vehicle Tracking System. The syatem is used by companies in various countries, but the specific traffic that I heard all come from one place: the Spratley Islands in the South China Sea. China is building artificial islands in the Fiery Cross Reef. The Chinese started their activities in 2015. The first transmissions from that area were noticed in early 2016. The tracking system uses CODAN equipment that sends selcalls to base stations. The base stations use the received data to track the ships, barges and cars used for the building activities. Sometimes GPS data is mentioned in the CODAN messages, but so far I have no idea how to read it.

Voice traffic has been heard in Mandarin following CODAN calls. These are actual calls, not the tracking devices. They are answered by the reverted tones sent by the receiver's CODAN radio to acknowledge the receipt of the signal.

Base stations IDs include: 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 1188, 6363, 6969, 7474, 7979, 9898, etc. Note the combinations: either XXXX or XXYY or XYXY. Easy to recognize. These IDs are in the "TO" field.

Frequencies in USB. The center frequency is 1785Hz higher.

7103, 7106, 7109, 7112, 7121, 7124, 7127, 7130, 7133, 7139, 7142, 7145, 7148, 7157, 7160, 7918, 7921, 7933, 7936, 7938, 8003, 8006, 8009, 8012, 8015, 8021, 8024, 8027, 8030, 8033, 8041, 8066, 8072, 8075, 8078, 8596, 9047, 9090, 11149, 11159, 11163, 11168, 13431, 13452 kHz and maybe more.

The Chinese are intruding the 7MHz HAM bands with this service.

Examples of GPS data:
ESN 117117
ESN 117255
]]>