Electronics & Radio - Reducing the noise from my camper's LED lights.

Ditch the diodes. Once conducting, they are a short-circuit for RF. Replace them with a pair of high-current inductors of a few mH followed by a 1uF capacitor between the wires to the battery. That will provide a high impedance path for the RF and the remaining bit is shorted by the cap. Do not use a common mode choke because the RF from the LED is differential mode.

 

Take 2 ferrites and call CQ in the morning.

 

Ummmmmm....Not quite sure exactly how to ask this but...

Where do you solder these caps on an XYL?

 

NO!

THE FERRETS INEVITABLY CHEW THROUGH THE WIRES BONNIE!

Come on girl! Keep up!

 

FCC Title 47 CFR, Part 15 governs Radio Frequency Devices... If the LED lights are powered by a Switching Power Supply (an RF Device) then Part 15 Class B is applicable. If the LED lights are powered from a Battery (not an RF Device) then Part 15 Class B is not relevant; conducted and radiated emission limits for non-intentional radiators would not apply. Of course this is my opinion because I am not a Radio Law Expert (NARLE).

Are the Camper Lights in question Battery powered or powered from the mains with a Switching Power Supply? Perhaps another section of the FCC Rules and Regulations is applicable to non-RF Devices?

Dan WQ4G

 

According to FCC Title 47 CFR, Part 15, a Radio Frequency device is a device that uses Radio Frequency energy, which is defined (§15.3 sub u) as electromagnetic energy at any frequency in the radio spectrum between 9 kHz and 3,000,000 MHz. Most -if not all- LED lamps incorporate a switching regulator to convert the constant voltage of the power supply, beit a mains supply or a battery, to a constant current through the LED. Such a switching regulator uses RF in the range as specified by FCC Title 47 CFR, Part 15.

 

2 - 3 wraps of both + and - of the 12 volt power leads through a ferrite will finish off the noise. It is important that the ferrite materal be type 31 material or it won't work.

 

say what you will,
this is what I used that worked.
I tried several configurations, thats what worked.
.

 

Reading through 47 CFR, Part 15...

I agree that §15.3 sub u defines Radio Frequency Energy as electromagnetic energy at any frequency in the radio spectrum between 9 KHz and 3,000,000 MHz. And, 47 CRF Part 15 does define several 'RF Devices.' It defines Incidental Radiators, Intentional Radiators, and Unintentional Radiators among other things, but does not define 'RF Device' specifically in 15.3.

But, the rules do say 'no harmful radiation is caused.' Now, define 'harmful.'

WQ4G

 

The rules also say that even if a device is compiant with Part 15, it ca still cause harmful interference. The word "harmful" is, in my opinion, used in so many places in Part 15 that it looses meaning. Harmful cannot be measured, an absolute radiated RF level can. So I think one should read/interpret Part 15 as: "we have set absolute limits to RF interference but it cannot be quaranteed that no device will ever interfere with another. So one must accept interference as long as it isn't harmful".

 

my problem is the LED monitors I have on my desk. I have a SDR radio and the computer and monitor that operate's the radio so i cant not run them when i am on my radio unless i buy another radio . that solution is not one i can afford right now. i have talked to alot of people done alot of reading on this and still haven't found away to at-least quite it down alittle.

 

Maybe you've already tried this (or even using this) but I've found that using a balanced antenna such as a dipole/doublet or a delta loop reduces computer/screen/shack RFI over using an unbalanced antenna like a long wire or an end-fed. This is because the interference in your shack is imposed on the ground of your transceiver and thus adding to singe ended received radio signals. If you have a balanced/symmetrical antenna, the RFI on your RF ground is imposed on both antenna terminals and thus cancelling each other.

 

Practical, simple and economical solution. Thanks for the video.

José Antonio
yy5eay

 

I remember ages ago when making modifications to a Eddystone EC10 transistorized coms Rx BFO. It involved adding a Z diode regulator. This was causing noise and required adding a inductance/capacitance filter to cut this out. No mention of this in the initial circuit diagram. I found it by chance in a book "Technical Topics for Amateur Radio" 73 de John - G0WXU.

 

Try putting a larder bypass cap on it maybe a .02mf