New (October 2013) LED wingtip landings light discovered

[rocketbob]

This is the ferrite I used: http://www.mpja.com/025in-ID-Ferrite...nfo/18466%20FL

Note that this ferrite core is significantly more substantial than the radio shack ferrite.

I tried several different capacitors of varying capacitance and types and did not find much of a change.

On my santa wish list is a spectrum analyzer to determine exactly what frequencies things like these LED lights bark at.

[bullojm1]

Originally Posted by rocketbob

On my santa wish list is a spectrum analyzer to determine exactly what frequencies things like these LED lights bark at.

Bob,

Have you ever looked at using a Software Defined Radio (SDR) spectrum analyzer? I was quite impressed with using the free Windows program SDRSharp(http://sdrsharp.com/) with an inexpensive USB SDR dongle (RTL2832U & R820T). You can pick up the USB SDR Dongle for about $15 shipped on Ebay. It works quite well - I have been able to detect 978Mhz and 1090Mhz ADS-B signals, AM, FM, Digital television and APRS signals. I am sure it would be good enough to find the frequency of the noise coming off these LED's.

[Bavafa]

Originally Posted by Toobuilder

One of my EE guys suggested a .1uF capacitor between power and ground, close to the light as possible.

How about using a shielded wire for the landing light? Do you guys think that would supperss all RFI?

I used the capacitor for my HID with no effect, not to say that it may not be useful in this situation.

I really like these flashlight type for LL if I find a solution for the RFI.

[catmandu]

Originally Posted by rocketbob

This is the ferrite I used: http://www.mpja.com/025in-ID-Ferrite...nfo/18466%20FL

Note that this ferrite core is significantly more substantial than the radio shack ferrite.

That IS quite the ferrite, and good price. Think I'll order a few. In the meantime, I'll try some shielded wire tomorrow.

[rocketbob]

Originally Posted by bullojm1

Bob,

Have you ever looked at using a Software Defined Radio (SDR) spectrum analyzer? I was quite impressed with using the free Windows program SDRSharp(http://sdrsharp.com/) with an inexpensive USB SDR dongle (RTL2832U & R820T). You can pick up the USB SDR Dongle for about $15 shipped on Ebay. It works quite well - I have been able to detect 978Mhz and 1090Mhz ADS-B signals, AM, FM, Digital television and APRS signals. I am sure it would be good enough to find the frequency of the noise coming off these LED's.

Yep I have been playing around with SDR#. Very cool indeed. I have thought it could be used as a spectrum analyzer, albeit one without any filtering.

[tikicarver]

I think I can get access to a spectrum analyzer at work. If so, I'll hook my light to it and post the results.

[Toobuilder]

How about bringing it over to my house (I'm off this Friday) and we can compare the two versions of this light?

[fl-mike]

I don't have need for one of these right now, but I do have access to a anechoic EMI room and test gear. I can do a full DO-160 radiated and conducted emissions screen on one if somebody wants to drop ship one to me. I'm kind of the resident EMI "fixer", at least on the stuff I don't design...

[wirejock]

I haven't done board level radio in a long time but I did stay in a Holiday Inn last night!
Sorry, couldn't resist.
Is it possible the RFI is coming from the light itself. Wrap that thing with aluminum foil and turn it on for a few seconds. Just long enough to see. If I read correctly, it's pretty close to the antenna.

[catmandu]

Tried using shielded wire today, no change. Bummer. Might have to abandon the trustfire.