GU10 LED electromagnetic interference

Good grief, what about us poor short wave fans and radio hams, is this yet another domestic device that does not pass the specs but nobody could give a monkeys?

Brian

This is an interesting report but there are other factors here that have to be at play rather than just the LED bulbs.

I think your coax cable may be missing a proper ground connection somewhere close to the point where you take your measurements. The LEDs are just not large enough of a load to create such big issues as to completely bring cable TV service down, even if you were to wrap your cable a couple of times around each bulb (I assume this is not the case).

How far is the cable from the LEDs anyway? Is the coax terminated in the same (properly rated) shared wall mounting box with the dimmer switch or otherwise close to it? If that's the case, the dimmer switch itself, not the dimmable LEDs, would be my best guess.

You will get a better feel for what is going on by listening to a radio on a clear frequency on LW and MW. To be fair, the interference might not be due to the bulbs per se, but more the way the dimmer is working when lightly loaded with just a few watts. Cue are resident expert Mr Gabriel.

Nobody could give a monkeys about newsgroup etiquette?

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re close to the point where you take your measurements. The LEDs are just n= ot large enough of a load to create such big issues as to completely bring = cable TV service down, even if you were to wrap your cable a couple of time= s around each bulb (I assume this is not the case).

The original post didn't mention cable TV. The broadband connection is probably ADSL over twisted pair telephone wire. No coax would be involved!

It is quite possible that the internal telephone wiring is running next to mains cables, so such interference could easily happen. If it is an ADSL service the best way to help overcome it would be to fit a "faceplate filter" to the telephone master socket and plug the modem/ router directly into this. Disconnecting the bell wire from the internal wiring can also be useful as doing so preserves the electrical balance of the telephone wiring, thereby reducing interference pickup, and with most phones does not cause a problem.

John

If you are complaining about top posting, then Brian has an agreed exemption in this newsgroup, as he is blind and it makes it easier for him.

SteveW

If you bypass the dimmer, is the interference still there?

Quite. I've had dimmers with tungsten wipe out a dial up connection. ;-)

The stupid BT three wire system is effectively unbalanced, so should really be in screened cable.

Hi, just to confirm some of the observations.

I do not have cable, I have ADSL.

The bulbs are dimmable models, but there are no dimmers used.

The internal extension wiring routed to my ADSL Router is not screened and does have three wires.

Paul R

The best way would be to site the router at the main BT socket, replacing that if not already done with a filter type. Then run to your computer using CAT5 cable. This is balanced and screened so much less prone to picking up interference.

Putting a 0.1uF cap across the LED as close to it as poss might also make a real difference.

NT

Cat5 or Cat5e is not normally screened it's just 4 twisted pairs (different pitch for each pair and far more twists per inch than Cat3 (aka CW1308, telephone cable).

You can get screened Cat5/Cat5e but the vast majority of stuff out there isn't screened.

responding to

Best Wishes John M0JAV

Paul R wrote:

dimmable light

dimmer and an interaction is set

which causes high

these dimmable units?

Hi, just to restate - whilst the bubls were dimmable, there was no dimmer involved, just a straight switch.

Paul R