6 ms·

speaking about interference : moved my home office to a new spot in the house the other day ago - which has 3 LED light bulbs for light in the space. Turned on

speaking about interference : moved my home office to a new spot in the house the other day ago - which has 3 LED light bulbs for light in the space. Turned on the ham radio - in scan mode - picked up someone talking, but noticed a bunch of static also being picked up. Didn't think much of it until I turned off the lights and the static went away. radio antenna was about 4 feet away from 2 diff bulbs (!). These things are noisy ..thinking about trying a few diff brands to see if there is a difference. also thinking about borrowing a buddy's spectrum analyzer to see if I can isolate the frequencies of the noise, might be able to put a a filter on the antenna.

Scoundreller 8y ago
I recall seeing a garage door manufacturer selling LED bulbs for $15 or $20 that don’t interfere with openers. Personally, I’d just cover the bulb in a few layers of grounded chicken wire. But I’m cheap like that.
- topspin 8y ago
  "Personally, I’d just cover the bulb in a few layers of grounded chicken wire. But I’m cheap like that." Shielding the bulb won't help when the switching PS in the bulb is making the house wiring resonate. RFI problems frequently fail to yield to silver bullet solutions.
  - Florin_Andrei 8y ago
    You may try to wind a few rounds of the AC wires to the LED bulb on a ferrite core. That may (or may not) reduce RF bleed through AC. (shrug) RF is hard.
robdachshund 8y ago
Pretty sure LED bulbs have a little rectifier and a switching regulator to get 5v dc. Most of the noise would be from the switching regulator, so I doubt there will be a difference between brands.
topspin 8y ago
There are serious RF interference problems with some LED, CFL lights and dimmer products. Even low power (5W) lights can swamp the spectrum badly enough to jam out DAB and FM radio receivers. [1] http://www.ledbenchmark.com/faq/LED-interference-issues.html http://www.ledbenchmark.com/faq/LED-interference-issues.html
- xxpor 8y ago
  I wish the FCC would crack down. These devices are in violation of Part 15.
- tzs 8y ago
  Also from some monitors and TVs. My Samsung monitor spews all across the 1.25 meter ham band. The form of the interference is a serious of regularly spaced narrow spikes across the whole band.
  - topspin 8y ago
    You might try adding snap-on ferrite beads to the power cord. If the monitor has an external switching power supply you could try replacing it; some of those are noisy. Otherwise, if it's an older monitor, the noise is probably coming from the CCFL power inverter (an internal AC power supply that powers the fluorescent backlight.) New monitors usually use LED backlighting.
- oh_sigh 8y ago
  Yes, I just installed new LED headlights in my car[0], and my FM radio gets staticy when I turn them on. [0] https://www.amazon.com/gp/product/B07D3H1HWL https://www.amazon.com/gp/product/B07D3H1HWL
  - topspin 8y ago
    There is a lot of information available about this problem and how to solve it. Read this for starters [1]. The cause is the LED "driver" (power supply) and power cables; the PWM supply is making your LED power cables radiate RF energy. [1] https://betterautomotivelighting.com/2014/12/31/how-to-remove-radio-interference-using-ferrite-coils-for-hid-and-led-headlights/ https://betterautomotivelighting.com/2014/12/31/how-to-remov...
semi-extrinsic 8y ago
For a room where you have radio equipment, I'd either install regular old incandescent bulbs, or DIY some LED strips driven by a constant-current linear voltage regulator (efficiency of the latter kinda negates the point of having LEDs though).
Florin_Andrei 8y ago
Yeah, my big plasma TV makes a heck of a lot of noise in the 70 cm band. I need to keep the rubberducky antenna far from it if I want to be able to receive anything. Also, I've replaced the headlights on my car with LEDs. Much better visibility now, but the FM radio performs much worse. I'll have to figure something out, it's annoying.

Scoundreller 8y ago

I recall seeing a garage door manufacturer selling LED bulbs for $15 or $20 that don’t interfere with openers. Personally, I’d just cover the bulb in a few layers of grounded chicken wire. But I’m cheap like that.

topspin 8y ago
"Personally, I’d just cover the bulb in a few layers of grounded chicken wire. But I’m cheap like that." Shielding the bulb won't help when the switching PS in the bulb is making the house wiring resonate. RFI problems frequently fail to yield to silver bullet solutions.
- Florin_Andrei 8y ago
  You may try to wind a few rounds of the AC wires to the LED bulb on a ferrite core. That may (or may not) reduce RF bleed through AC. (shrug) RF is hard.

robdachshund 8y ago

Pretty sure LED bulbs have a little rectifier and a switching regulator to get 5v dc. Most of the noise would be from the switching regulator, so I doubt there will be a difference between brands.

topspin 8y ago

There are serious RF interference problems with some LED, CFL lights and dimmer products. Even low power (5W) lights can swamp the spectrum badly enough to jam out DAB and FM radio receivers. [1] http://www.ledbenchmark.com/faq/LED-interference-issues.html http://www.ledbenchmark.com/faq/LED-interference-issues.html

xxpor 8y ago
I wish the FCC would crack down. These devices are in violation of Part 15.
tzs 8y ago
Also from some monitors and TVs. My Samsung monitor spews all across the 1.25 meter ham band. The form of the interference is a serious of regularly spaced narrow spikes across the whole band.
- topspin 8y ago
  You might try adding snap-on ferrite beads to the power cord. If the monitor has an external switching power supply you could try replacing it; some of those are noisy. Otherwise, if it's an older monitor, the noise is probably coming from the CCFL power inverter (an internal AC power supply that powers the fluorescent backlight.) New monitors usually use LED backlighting.
oh_sigh 8y ago
Yes, I just installed new LED headlights in my car[0], and my FM radio gets staticy when I turn them on. [0] https://www.amazon.com/gp/product/B07D3H1HWL https://www.amazon.com/gp/product/B07D3H1HWL
- topspin 8y ago
  There is a lot of information available about this problem and how to solve it. Read this for starters [1]. The cause is the LED "driver" (power supply) and power cables; the PWM supply is making your LED power cables radiate RF energy. [1] https://betterautomotivelighting.com/2014/12/31/how-to-remove-radio-interference-using-ferrite-coils-for-hid-and-led-headlights/ https://betterautomotivelighting.com/2014/12/31/how-to-remov...

semi-extrinsic 8y ago

For a room where you have radio equipment, I'd either install regular old incandescent bulbs, or DIY some LED strips driven by a constant-current linear voltage regulator (efficiency of the latter kinda negates the point of having LEDs though).

Florin_Andrei 8y ago

Yeah, my big plasma TV makes a heck of a lot of noise in the 70 cm band. I need to keep the rubberducky antenna far from it if I want to be able to receive anything. Also, I've replaced the headlights on my car with LEDs. Much better visibility now, but the FM radio performs much worse. I'll have to figure something out, it's annoying.