Green Interference!!!

[ZL1RS]

Philips CFLs (two different styles) and Philips LEDs (bayonet and Edison screw according to the light fittings) ... all quiet as far as I can tell.

73,

[VK4CZ]

Slowly converting house to Philips LEDs and no issues so far (probably 20% done) but all the ALDI LEDs 'bulbs' have all been thrown out now

[VK7ZGK]

entire house uses Philips LED lamps and there is no trace of interference at all. cheers all

[VK2FLR]

I tried LED lights purchased cheaply at a Wyong field day some years ago to replace halogen 50w lights running off 12 volt iron cored transformers. S9 hash everywhere of course. Capacitors across the pins of each LED made no apparent improvement.

After some trial and error testing I now use Philips LED MR 6 5.5w 3000K which are almost inaudible on 10 metres and inaudible on 2 metres. They cost a bit more but do the job in RF silence.

[VK5TM]

Anyone had trouble with the 12v Philips one's dying?

I've got two, one died after 3 months and the other one keeps flickering.

Can't tell what the power supply is (other than 12v), as I have to lift the roof to get to it (horrible flat roofed house design).

[VK4TIM]

What's the best store to get the Philips LED downlights? are these the ones that can be found at Wooloworths and Coles or lighting places, electrical wholesalers or Bunnings?

Also, on this, what are the best 240-12V "Transformers"to use with the LED lights, ones that don't radiate crap.

Have got some 7W LED lights in the kitchen and dining room/lounge, one light still uses a good old iron cored transformer (no noise), but if the kitchen light is on, then it's S9 noise floor.

Should we collectively list the manufacturers/parts of commonly available LED lights, that people have found to be OK, to share for each other's information?

[ZL2BKC]

entire house uses Philips LED lamps and there is no trace of interference at all. cheers all

The Phillps ones are good, at least the ones that I have tested.

Several months ago I setup a LISN and measured a number of GU10 lights. Screen shots were taken and if anyone is interested Im happy to post for a reference.
Over the years I had accumulated various lights from China (eBay, Banggood, aliexpress) while outfitting the house so I had several test candidates on hand. Basically all but one of them met the domestic EMC standards. Pulling them apart the worst offenders used only a few transistors (2??) for the switching function.
The better ones used an IC, but the smarts inside the IC used spread spectrum techniques to "modulate" the PWM frequency to move the noise from a single carrier to a "wideband" noise floor about 10-15dB down. This is a common trick used these days to meet EMC regulations.

Given the size constraints of GU10 I thought the 12V LEDS would be better with more room for EMC compliance details in the 240V to 12V converters, so 12V downlights would be lower noise. I was wrong (by many dB!) - the loop area of the 12V supply is larger (ie. 1 foot long) with 20 times the RMS current. To be dimmer compatible the transformers PWM modulate the output based on leading/trailing edge which creates large rise fall times... and that is not pleasing to hams nearby

The absolute winners were the Phillips and "Click" brand 4W GU10 lights. Instead of a complex switchmode regulator they were completely passive inside. These are completly sealed plastic units which I have not taken apart yet, but I suspect it uses a series capacitor circuit. ie. http://www.marcspages.co.uk/tech/6103.htm

Turns out that the LED bulbs with the switchmode guts are dimmer compatible which lots of RF noise. Do away with the dimmers and choose the passive LED lights and it will be as quiet as Edison had intended.

The Click brand is available from Bunnings - make sure it is the 4W plastic version as they have a higher wattage version which is still switchmode.

The Phillips bulbs are expensive, so since I needed to help fund the LISN part of the science project I have outfitted the house with the click brand of lights. HF bands are now usable but there is still room for improvement. Next step is to talk to the neighbours

Note I did try various techniques to sort out the common mode noise with inline filters, X2 + Y2 Mains caps (which were missing in the lights) and soon gave up as the next step involved an eddystone die cast box, which would defeat the LED's intended purpose.

73,
Wayne ZL2BKC