Recently this situation has resulted to running some Tuesday night UKAC events by the light of a (non LED) bedside lamp, with all other lights off!
I was told LED lights had got better in the intervening years, interferencewise, so I bought some more LED samples from Tesco, B&Q and recent samples from Homebase to see if they had. The Tesco ones were the best of the collection, but still produced a noise floor increase.
It was at this point that Roger G4BVY posted to the MHRAC reflector that he had bought some Phillips 4.5W LED in twin packs for 9.99 from Wickes from which he could detect no interference and they were quite bright. Off to Wickes in Worcester to buy a couple:-
|The GOOD LED Lights|
Installed them in the stairs lights listened on 144MHz turned the lights on...Nothing! The noise floor did not increase at all!
I was intrigued how much the noise floor increased on 2m for each type, so I needed a calibrated receiver. The easiest option was to use the SDRIQ in continuum mode with my Nacton transverter for 144MHz. The increase in noise floor could be easily seen in dB.
|The effect of turning on the Homebase lamp on the 2m noise floor|
The overall results were Interesting:-
Homebase 6W (2012) 24dB
TCP 5W (Homebase) 26dB
TCP 4W (B&Q) 18dB
Tesco 5W 8dB
Phillips 4.5W 0dB
The Phillips was by far the best. Interestingly Homebase don't actually sell their own brand any more, they only sell TCP so I got one of their 5W ones. haven't improved their version, It was returned as "unfit for purpose"! I was so impressed by the Phillips I went back to Wickes to get replacements for all the other Homebase lights. Before fitting the new ones I decided to see how the Homebase LED interference varied with frequency. This time I used the SDRIQ with external Nacton transverters for 6, 4 and 2m. The noise floor increase was as follows:-
As a check, I also measured the results using my ANAN-10 as the receiver. The results were within +-1dB
The remainder of the Phillips LED were fitted. For the record the twin packs have the UPC 8718291789994. I looked on all the frequencies I had (even 136kHz) but couldn't find a noise floor increase. Good news all around; lower noise, decreased power consumption and Meg says that, unlike the previous LEDS the increased brightness will even support her sewing! Thanks Roger.