PV Installations and EMI

[JohnW2]

This (which hadn't previously occurred to me) may well be of more general interest than just to radio amateurs, since it is apparently already starting to impact a wide range of radio communications.

This month's RSGB journal ("RadCom") came through my letterbox today, and the (8-page) 'cover article' related to radio frequency interference being caused by the high-current inverters of the growing number of PV installations. A lot of the article is about the technical side of what sort of filtering and screening (of cables etc.) can help to mitigate this problem, but a major thrust of the article is to point out that many/most PV systems are being sold and installed with far too little filtering/screening to minimise this growing problem.

... so perhaps a 'downside' of PV installations (which presumably is going to become progressively more widespread) that I'd never previously thought about!

Kind Regards, John

 

[fourtytwo]

This is indeed a growing problem if you are unfortunate enough to have equipment affected by it (EMI). In my case where I used to live there was a car workshop in the village with "electronic ballasts" on the large number of fluorescent tubes that literally ĸnocked out my DSL (internet) and blotted out several BBC radio stations on AM. I tried for several years to get various authorities interested but never succeeded. Fortunately I left the problem behind when I moved away. I believe this problem was created like Grenfell tower by so called de-regulation.

CE (Chinese Engineering) marks are useless as they are all self-certification and untested by any independent authority whatsoever so anything goes!

 

[ericmark]

I joined UKRS and left RSGB when the RSGB wanted to keep the requirement for morse code, the UKRS stopped, there was no need for it once the RSGB saw sense, but I never re-joined.

There have been a lot of problems with interference from items like induction hobs, and power line adaptors, the latter technically not permitted, but still sold, and I found my SkyQ boxes use it. But there are very few rules about selling equipment which should not be used.

Guns are restricted, but in Hong Kong I had to produce my amateur radio licence (VR2ZEP) to buy amateur radio equipment, but this country no such restrictions, and I do wonder if my cheap hand held radios do comply? In real terms, the main concern, is not us playing radio, but safety radio communications. Like with my local railway, where line side telephones have gone, and they rely on a repeater halfway along the line, and hand held radios. Be it Police, Ambulance or fire service, they all still use radios, but as to how to work out who or what stops them working is not easy.

And no one seems interested in HF. I wonder how many are still interested in amateur radio, my son licensed at 14 has let his licence drop, a GW call sign as well, they must be getting rare? But what can we do?

73 VP8BKM

 

[JohnW2]

There have been a lot of problems with interference from items like induction hobs, and power line adaptors, the latter technically not permitted, but still sold, and I found my SkyQ boxes use it. ...

Yes, we're aware of such sources of EMI (which you and I once called "TVI" ) but, as I said, it had not occurred to me that the increasing number of poorly-designed PV inverters were becoming an increasing issue in this respect.

.... Be it Police, Ambulance or fire service, they all still use radios, but as to how to work out who or what stops them working is not easy.

Indeed, that's one of the points made fairly strongly in the article. There are a good few other areas in which satisfactory radio communication is 'safety critical' (e.g. communication with aircraft).

And no one seems interested in HF. I wonder how many are still interested in amateur radio, my son licensed at 14 has let his licence drop, a GW call sign as well, they must be getting rare? But what can we do?

What can we do? ... probably just become nostalgic about a relatively brief period in past history, I suppose, when experimenting with the technology was in its infancy and having the ability to communicate with people vast distances away was a definite novelty!

Apart from the (then inevitable) initial activity on 'top band', I never had any great interest in HF, other than for some contest work. I ceased to be active many decades ago, when it all turned primarily to a matter of "buying complex (and expensive) off-the-shelf boxes". My interest, back in the 60s related primarily to the design and construction of what were then very 'innovative' items of VHF/UHF gear, and my use of it really only served to reassure me that it actually worked!

At a time when few people even considered using anything but valves for VHF, I produced semiconductor-based receiving (and, eventually, transmitting) gear for 2m, 70cm & 23 cm and, together with colleagues, I engaged in quite a lot of experimentation with meteor scatter and EME communication on those bands (for which I had one of the few 'high power licences' for a while).

I joined UKRS and left RSGB when the RSGB wanted to keep the requirement for morse code, the UKRS stopped, there was no need for it once the RSGB saw sense, but I never re-joined.

I've been a member of the RSGB ever since the age of 12 or 13, prior to getting my licence on my 14th birthday (the earliest then possible), having taken the morse test a few days earlier. At that age, morse was very easy to learn, and I rapidly became pretty proficient (up to well over 30 wpm, when the test was 12 wpm) - and some of the things I subsequently did, particularly the meteor scatter, would have been impossible without it.

Morse also represents the only way in which I would be able to communicate with the outside world if I found myself 'shipwrecked on a desert island' with (somehow!) a source of electricity and an extremely limited source of what one might call 'electronic components' - even if I had to resort to a 'spark transmitter' and a 'crystal set'

 

[SUNRAY]

AFAIC the PWM control of PV systems created RFI right from the first installations, especially those on remote radio sites where no mains supply is available and linear (wasteful) solutions have been impemented by the radio engineers, equally power line adapters are terible and yes Skye proudly boast about their 'inovative system', A friends neighbour was using such a system which actually wiped out one of the local TV channels prior to digital switchover, on a SA the selection of significant signals it radiated was horrendous but as enough neighbours complained 'the authorities' did sit up and take notice but it took several months.

I was involved with Amateur Radio from about 1970 (age 15) but dropped out of the radio club due to committee politics, dabbling with CB (Due to a girlfriends brother) and the AR interest amongst the users and discussions with one of my college lecturers in 1983 when the exam was in the multiple choice experiment I joined in his college course half way through (and mostly sat there bored) achieved credit and distinction, eventually applying for a license and missing 6RAY by 3 days achieved my initials 6RVS. I tried to get to speed on CW but the 8-9WPM plateau beat me several times but when the novice license was introduced and they eventually allowed the appreciation test to be sufficient for an M3 call I did that and sat the test with several others, it was a farce as we were told what the format of the received message would be and the examiner even used his own callsign which we all knew. He must have sent exactly the same message half a dozen times for one guy then moved on to sending - --- -- -- .. . about 8 times in a row and we boiled a kettle in the time took. Of the small group I was the only one to send and receive 2 messages without errors but I've never make any sort of claim I can read send CW.

I currently hold my G6, M3, 2 repeater & 2 club calls. but my only operation is pretty much limited to Raynet work and mostly on 2/70.

 

[JohnW2]

.... discussions with one of my college lecturers in 1983 when the exam was in the multiple choice experiment I joined in his college course half way through (and mostly sat there bored) achieved credit and distinction, eventually applying for a license ....

As illustrated before, I certainly pre-dated the MCQ version of the RAE, this being the one I did in 1963 ...

I tried to get to speed on CW but the 8-9WPM plateau beat me several times ...

By 1983 (if that's when it was) you were probably a little old for learning morse to be "child's play" but, as I said, at 12 or 13 I found it extremely easy, and still retain some capability (albeit not speed) even today, some 50 years after I last used it!

 

[SUNRAY]

As illustrated before, I certainly pre-dated the MCQ version of the RAE, this being the one I did in 1963 ...


By 1983 (if that's when it was) you were probably a little old for learning morse to be "child's play" but, as I said, at 12 or 13 I found it extremely easy, and still retain some capability (albeit not speed) even today, some 50 years after I last used it!

I'd have been 28 when I took the RAE in 83 although My initial CW lessons were C1970-72 (15-17) where a group of around half a dozen went to a G4's QTH twice a week, oh boy do I remember: first session EISH, 2nd TMO, 3rd EISHTMO and truthfully they still jump out at me upto around 10WPM although without context. However as mentioned I then left the hobby for 10 years.
My reason for giving dates earlier was simply position it in time and very much not as a 'I've been there that long'. In my early days there were numerous GnXX and first half of alphabet G3's calls around although the whole of G3 had been issued and very early G4's.

These days dah dit dah dit dah dah dit dah to maybe beyond 30WPM totally smacks me in the face and I may detect the subsequent G or M but that's as far as it goes.

One ditty I have (no not I I) is I made plans to go out one evening with a colleague and picked him up from home, he wanted to see his father in hospital which was on the way to our destination. I'd got to know his father quite well through repairing our rusting cars in their garage so went in too. He was in a coma but we were talking to him, all the time we were there his hand was shaking and one of the nurses explained they didn't know why. Sunray says: "That's easy, it's Morse code." I added: "Sorry I can't read it" when the actions dramatically changed. We went back the following evening with a datong reader and key, placed it under his hand and immediately read "Hello Ray" then we sat chatting with him. The same nurse came into the room and asked us what the thing was, she was so taken aback when she read her name on it she pressed the crash button for other medical personal to see it.

During the war he was a Royal Navy radio operator and for a few years after in the Merchant Navy.

 

[JohnW2]

I'd have been 28 when I took the RAE in 83 although My initial CW lessons were C1970-72 (15-17) where a group of around half a dozen went to a G4's QTH twice a week, oh boy do I remember:

As I said, it really does get much easier (and long-lasting) the younger one is.

Remembering that it is probably at least 50 years since I last used it, I've just tried, and seemingly can still happily 'send' morse at something like 20 wpm with a basic morse key (on left of pic) and 30+ with a mechanical 'bug' key (right in pic). I'm going to try to find (or create if I have to) some morse to see what I can 'read' - I imagine only possible at appreciably lower speeds than I once could do!
[the choke, capacitor and resistor wired to the basic key in the photo are a "key click filter" (per Q2 in the RAE I posted above). Somewhere I have some electronic 'bug' keys, but can't find them ]

These days dah dit dah dit dah dah dit dah to maybe beyond 30WPM totally smacks me in the face and I may detect the subsequent G or M but that's as far as it goes.

I think that that (and maybe some other things - like our own callsigns) will probably smack both you and I into the face, at almost any speed, until the day we die!

.... He was in a coma but we were talking to him, all the time we were there his hand was shaking and one of the nurses explained they didn't know why. Sunray says: "That's easy, it's Morse code." .... We went back the following evening with a datong reader and key, placed it under his hand and immediately read "Hello Ray" then we sat chatting with him.

In the case of patients who were sufficiently conscious to be 'with it', but who had very limited motor capabilities (unable to speak, write or use a keyboard etc.) I have occasionally seen that done (using finger taps, eyelid blinks or even tongue movements etc.) when (unusually) the patient was already familiar with morse - but, given the absence of any 'readers' in the era concerned, required one to find someone who could 'read' it!

Much more commonly (given that not many people are familiar with morse) I've seen similar patients taught simple codes (e.g. "one short tap for yes, two for no, three for hungry, one long tap for pain etc.).

 

[mattylad]

I passed the RAE in 93 (G7), prior to that I was very active on radio and still was for several years after.
However every time I try to rekindle the hobby there is ultimately one thing that ruins it for me, interference be it from ADSL or other sources, either way it's all I get on my HF rig so now I don't bother with radio.

It's still sat beside me but no point using it as either I cannot hear much or I'll cause interference.
I'm not wanting to load the car up and go up a hill either.

I tried morse, I could never get the hang of receiving it.

 

[SUNRAY]

In the case of patients who were sufficiently conscious to be 'with it', but who had very limited motor capabilities (unable to speak, write or use a keyboard etc.) I have occasionally seen that done (using finger taps, eyelid blinks or even tongue movements etc.) when (unusually) the patient was already familiar with morse - but, given the absence of any 'readers' in the era concerned, required one to find someone who could 'read' it!

All the time the key was correctly positioned under his hand he was able to chat quite freely and (I accept probably incorrectly) the only part that he seemed to have any control over was his grip/hand, when asked if he could do other things; wiggle toes, other hand/fingers, lips. tongue, eyes etc. He would tell us he was doing those things and equally telling us he couldn't feel things being done to him.

This would have been summer of 1983, I was 28 so his son would have also been I assume he was born about mis 30's. He made a full recovery and went back to work after Christmas. He recalled the horrible buzz of the morse reader pretty much everytime we met (right up to June 2019) and was a specimen of good health until he passed in his sleep at the end of that summer.

As an aside to this the G6M-- I borrowed the reader from passed away this Monday

Much more commonly (given that not many people are familiar with morse) I've seen similar patients taught simple codes (e.g. "one short tap for yes, two for no, three for hungry, one long tap for pain etc.).

Yes I'm aware of such, and I assume it was similar for him but the reflex CW was masking any comprehension.

 

[JohnW2]

All the time the key was correctly positioned under his hand he was able to chat quite freely and (I accept probably incorrectly) the only part that he seemed to have any control over was his grip/hand, when asked if he could do other things; wiggle toes, other hand/fingers, lips. tongue, eyes etc. He would tell us he was doing those things and equally telling us he couldn't feel things being done to him. .... This would have been summer of 1983 .... I assume he was born about mis 30's. He made a full recovery and went back to work after Christmas. .... and was a specimen of good health until he passed in his sleep at the end of that summer [2019]

Interesting story. Do you happen to recall (if you ever knew) what was wrong with him (medically) to result in his being in that state?