DAB radio interference

[swill453]

Wow. That is excellent Scott. Which provider please?

Sky Mobile. Uses O2 network. Looks like it costs £12 now, though the 25GB/month deal is on special at £13/month https://www.sky.com/shop/mobile/plans

Scott.

[XFool]

...Um.

Couple of subsidiary questions. Is DB radio mains operated? Can you get strobing effects from one of the LED bulbs? Such as moving open fingers rapidly in front of eyes, or from say fast dripping tap in kitchen?

Mains, yes. Strobing? Not quite sure what you expect to see - moving fingers create a strobe anyway, but I can't see a difference between LED and non LED bulbs.

I was wondering about the nature of the power being fed to the LEDs, whether constant of switching on/off.

I can not see how an LED device in itself, fed with DC, would directly generate interference. So it must be something to do with the circuitry used to feed it. This could be in the LED 'bulb' itself, on the external power supply. I can only assume it originates somewhere in the chain of how the mains 240V AC is turned to the low level DC that actually powers the LED device in the bulb. The LED device is a diode (D!) so if supplied with AC is going to rectify it and the sharp cutoff in the AC signal might be generating RF harmonics.

Also, there is the question of whether the interference is getting into the DAB radio via the mains wiring or directly to the radio as RF interference via the aerial. Another, battery, DAB might be able to differentiate between mains borne of direct radiation - albeit a different radio would be different and might itself be less sensitive to interference.

Have you looked at that forum kempiejon mentioned?

https://conversation.which.co.uk/technology/led-bulb-radio-interference-dab-test/

[Dod101]

What an interesting subject, and it's brought out some views on radio too.

From what people say, it isn'y my imagination, and LEDs can effect DAB. As for DAB being yesterday's technology, that's a laugh! In terms of radio and the duration of radio history, it's only just been invented and still hasn't been fully accepted by the population. I've noticed the signal from my phone played through the bluetooth connection on my radio is much better than the dodgy reception on either FM or DAB. But outside the house, this isn't an option because I have a minimal phone contract.

As for data (and mobile data) becoming cheaper: not everyone can afford endless data for radio or TV. Why should people who can ill afford it find it necessary to cut themselves off or pay out additional cash? I think talk of the BBC eventually going all streaming is a bad idea for many people, and as a society - particularly with regard to the things which "bind" us like news and entertainment - we should look after everyone, not just the well off. Which is also an argument against those virtually non-tax paying disruptors dipping their hands into our pockets.

FM works quite well in the car - though I rarely have it on because of the road noise - and I believe DAB didn't catch on due to fears of loosing signal. I can't see internet radio in cars being practical due to the cost of data. It makes no sense to have people pay additional costs when there is a good "free" system available.

Arb.

My car has FM and DAB. I use the latter when I can but where I live I can easily lose both on certain routes. I listen to radio more or less whenever I am in my car and at home from time to time but never when I am out and about on foot. I prefer peace and quiet.

Dod

[AleisterCrowley]

...
I was wondering about the nature of the power being fed to the LEDs, whether constant of switching on/off.

I can not see how an LED device in itself, fed with DC, would directly generate interference. So it must be something to do with the circuitry used to feed it. This could be in the LED 'bulb' itself, on the external power supply. I can only assume it originates somewhere in the chain of how the mains 240V AC is turned to the low level DC that actually powers the LED device in the bulb. The LED device is a diode (D!) so if supplied with AC is going to rectify it and the sharp cutoff in the AC signal might be generating RF harmonics.

Also, there is the question of whether the interference is getting into the DAB radio via the mains wiring or directly to the radio as RF interference via the aerial. Another, battery, DAB might be able to differentiate between mains borne of direct radiation - albeit a different radio would be different and might itself be less sensitive to interference.

It'll be the dreaded Switch Mode Power Supplies (SMPS) which are a very efficient way to change and regulate voltages, but which involve high frequency switching - giving rise to a lot of radiated interference if poorly designed/implemented

[XFool]

...I was wondering about the nature of the power being fed to the LEDs, whether constant of switching on/off.

It'll be the dreaded Switch Mode Power Supplies (SMPS) which are a very efficient way to change and regulate voltages, but which involve high frequency switching - giving rise to a lot of radiated interference if poorly designed/implemented

Yes, that's another possibility, if used to convert the mains to the 12 V supply. But if the original 12 V supply was for halogen bulbs, why would it need to be DC? It might just be because a SMPS was used by default rather than a transformer. But then, why no problem with the original bulbs? Unless the LED loading was upsetting the SMPS in some way.

Or am I confused by subsequent posts? What was the original supply voltage to this circuit? How was it derived?

(Yes, it was given as "12 V" - but no further details, apart from "mains" powered DAB radio.)

[AleisterCrowley]

...I was wondering about the nature of the power being fed to the LEDs, whether constant of switching on/off.

It'll be the dreaded Switch Mode Power Supplies (SMPS) which are a very efficient way to change and regulate voltages, but which involve high frequency switching - giving rise to a lot of radiated interference if poorly designed/implemented

Yes, that's another possibility, if used to convert the mains to the 12 V supply. But if the original 12 V supply was for halogen bulbs, why would it need to be DC? It might just be because a SMPS was used by default rather than a transformer. But then, why no problem with the original bulbs? Unless the LED loading was upsetting the SMPS in some way.

Or am I confused by subsequent posts? What was the original supply voltage to this circuit? How was it derived?

(Yes, it was given as "12 V" - but no further details, apart from "mains" powered DAB radio.)

I don't know how 12V LED bulbs work (I have 230V GU10s which are a bit noisy) but if they have a series chain of 10-20 LED chips within, there's probably a SMPS 'boost' converter in each to step up 12V to >20V

[XFool]

I don't know how 12V LED bulbs work (I have 230V GU10s which are a bit noisy) but if they have a series chain of 10-20 LED chips within, there's probably a SMPS 'boost' converter in each to step up 12V to >20V

I still have the broken base(!) of the only mains LED 'dimmable bulb' I ever bought - the +20,000 hours life one that lasted ~20 secs - it definitely has a board of electronics in it which could be a small SMPS. There would only ever need to be one per unit. But I don't know the situation with '12 V' LEDs.

If these things do all have SMPS in them, that spells trouble... I am already finding, where I live, that the RF environment seems to be going to pot, for one reason or another.

[AleisterCrowley]

There's going to be a SMPS in a mains one . I just ran my portable radio (off station, on AM) across my six GU10 LEDs in the kitchen and there is hash from all of them. They are a mix of Sainsbury's, Wilko and Philips - and the levels were noticeably different (and no, I don't know which are which, and I'm not dropping them out just to check...)

[XFool]

There's going to be a SMPS in a mains one . I just ran my portable radio (off station, on AM) across my six GU10 LEDs in the kitchen and there is hash from all of them.

I am currently using an AM/FM tuner. Obviously it has been years, indeed decades, since I listened on AM. When, out of simple curiosity I switched to AM, I was appalled by what I heard (very directional as well). AM is not FM but, back in the day, it was NEVER like THAT!

I am still on good(?) old ADSL2+ and, a few years ago now, I used to get a reliable ~18 Mbps download at 3 dB SNRM. Not now. It barely reaches 15 Mbps at 6 dB SNRM. OK, it's still enough for me, but it feels as if something has changed in the environment. Then we come to recent FM and DTV reception...

[Arborbridge]

...I was wondering about the nature of the power being fed to the LEDs, whether constant of switching on/off.

It'll be the dreaded Switch Mode Power Supplies (SMPS) which are a very efficient way to change and regulate voltages, but which involve high frequency switching - giving rise to a lot of radiated interference if poorly designed/implemented

Yes, that's another possibility, if used to convert the mains to the 12 V supply. But if the original 12 V supply was for halogen bulbs, why would it need to be DC? It might just be because a SMPS was used by default rather than a transformer. But then, why no problem with the original bulbs? Unless the LED loading was upsetting the SMPS in some way.

Or am I confused by subsequent posts? What was the original supply voltage to this circuit? How was it derived?

(Yes, it was given as "12 V" - but no further details, apart from "mains" powered DAB radio.)

Just to clarify: I haven't changed the supply and there is no dimmer mechanism in the circuit The original bulbs are 12volts on the mains circuit, and I've swapped out 4 of the 6 now to 12v LEDs GU5.3 MR16 bulbs. I seem to remember they were 35W which was less than the original 50W bulbs which I replaced. I've no idea where the transformers are, but I'm assuming they are above the ceiling near each downlighter unit.

Hope that gives the missing info.

Arb.

[Arborbridge]

There's going to be a SMPS in a mains one . I just ran my portable radio (off station, on AM) across my six GU10 LEDs in the kitchen and there is hash from all of them. They are a mix of Sainsbury's, Wilko and Philips - and the levels were noticeably different (and no, I don't know which are which, and I'm not dropping them out just to check...)

I might try that, if I can find an old AM radio in the house.

Incidentally, I used to live in London and AM worked OK on my BandO system, but now - in West Sussex - this same radio will scarcely work. Luckily, I can pick up Radio 3, but not 4, plus some ghastly dross I wouldn't want anyway. Conversely, I would say the DAB signal is much better here than in London (near Croydon) but teh BandO won't receive DAB. The DAB signal now seems to be rubbish for whatever reason.

Fortunately, the TV signal seems good here on all channels.

Arb.

[Arborbridge]

Wow. That is excellent Scott. Which provider please?

Sky Mobile. Uses O2 network. Looks like it costs £12 now, though the 25GB/month deal is on special at £13/month https://www.sky.com/shop/mobile/plans

Scott.

All the Sky deals seem very good - even the ones not on offer, so tempting.

Anyhow, the question remains (for me) given that "steam radio" works, why would I want to pay an extra premium. Of course, in the context of this conversation, it's true that the whole problem is that DAB and FM are not working well - that does beg the question "Why NOT?" Who or what is screwing up what used to a functioning free service to most UK households? Not being paranoid, but one does wonder why we are being pushed away from a simple free system to one which presumably fills someone's boots and costs load of dosh requiring people to change their radios and systems. DAB is certainly an improvement - when it works, it works much better than FM.
Radios function well for decades, and one reason DAB didn't catch on was that it required chucking out perhaps half a dozen radios per household for not much gain (depending on one's signal). If there hadn't been a decoding delay, it would have been a different story - we could then mix and matched without echoes around the house.

Arb.

[AleisterCrowley]

As mentioned before, I know very little about the 12V LEDs/halogens


My mains GU10s are a drop in replacement for halogens so 230VAC
Your 12V halogens were (I assume) fed from 12VAC from a transformer

Are your LEDs explicitly a drop-in replacement for 12VAC halogens? If they are 'expecting' 12VDC from a LED driver transformer you may have issues...

[AleisterCrowley]

https://www.downlights.co.uk/faq-how-to ... o-led.html

[bungeejumper]

I used to live in London and AM worked OK on my BandO system, but now - in West Sussex - this same radio will scarcely work. Luckily, I can pick up Radio 3, but not 4, plus some ghastly dross I wouldn't want anyway. Conversely, I would say the DAB signal is much better here than in London (near Croydon) but teh BandO won't receive DAB. The DAB signal now seems to be rubbish for whatever reason.

DAB is a postcode lottery - if you've got a good signal where you live, you won't ever understand why other people get hysterical about what will happen on the evil day when they eventually switch FM off.

For them, DAB just doesn't work at all. That's because it relies on a line of sight from the transmitter to your receiver, and not everyone's got one of those. Hills and stuff.

We're about five miles from Bath, and we can get about four stations from the south side of the house (all of them pop), and no stations at all on the west side. Quite a large part of Bath itself can't get a clean DAB signal either. Those bloody hills again. Somebody really ought to do something about getting them all flattened.

BJ

[XFool]

Anyhow, the question remains (for me) given that "steam radio" works, why would I want to pay an extra premium. Of course, in the context of this conversation, it's true that the whole problem is that DAB and FM are not working well - that does beg the question "Why NOT?" Who or what is screwing up what used to a functioning free service to most UK households?

Well yes. This last summer* I came close to feeling I was staring at the coming death of 'Wireless Broadcasting' as we have known it - that is in the James Clerk Maxwell, Heinrich Hertz, Guglielmo Marconi sense.

DAB is certainly an improvement - when it works, it works much better than FM.

Whoa Tiger! Discuss.

Radios function well for decades...

Err... They used to. But, if your portable battery DAB radio has a Software Defined Radio chip (I guess they all will now), it's a case of: "This radio will self destruct in... a much shorter time than you guessed when you paid for it."

...and one reason DAB didn't catch on was that it required chucking out perhaps half a dozen radios per household for not much gain (depending on one's signal). If there hadn't been a decoding delay, it would have been a different story - we could then mix and matched without echoes around the house.

Welcome to the digital (Time Domain process) world!

Oops! Just listening to BBC R4 (The BBC Home Service!) on FM, so gotta execute an emergency changeover, right now. From Crystal Palace to Wrotham, or the other way around. It wasn't like this in the 1950s, or the 1960s, 1970s, 1980s, 1990s, 2000s, 2010s. Oh well! That's progress, I guess...
At least that funny noise on R4 seems to have gone now. (See other thread!)

* OK, last summer had some very fine, warm, high pressure weather and likely there was some tunnelling in the ionosphere from the continent. But then, if only digital wasn't so GO/NO GO.

[AleisterCrowley]

I tried to tune in to station 2MT broadcasting from the Marconi Works at Writtle the other day, and couldn't get a signal.

[XFool]

I tried to tune in to station 2MT broadcasting from the Marconi Works at Writtle the other day, and couldn't get a signal.

It's still out there, somewhere!

And the way things are going, you'll soon have a better chance of hearing it than I will of hearing R4, or watching TV.

[XFool]

I tried to tune in to station 2MT broadcasting from the Marconi Works at Writtle the other day, and couldn't get a signal.

It's still out there, somewhere!

I told you!

https://www.emmatoc.org/home

[didds]

DAB is a postcode lottery - if you've got a good signal where you live, you won't ever understand why other people get hysterical about what will happen on the evil day when they eventually switch FM off.

Of course veerybody and his dog was jumping up and down about the evil day when they were going to turn the "normal" TV signal off and youd have to have extra kit to just get free to air TV.

Remember that time? When you could only get maybe 7 stations if you lived in a postcode lottery area where you could get two ITV regions and a Celtic channel to augment your otherwsie 5 terestrial stations? And then that eveil freeview changeover requiring that extra piece of kit mneant you could get several hundren channels of drivel instead?

How long ago was that now? Did that time even exist ?

didds