[Boatanchors] Low Noise (RFI) LED lightbulbs, an update.

Mon Dec 28 19:31:01 EST 2015

Sounds like a winner.

I buy my LED lighting by the reel.  $11 for 16.5 feet of high intensity hot white (6k) LEDs spaced about 1/4 inch center to center, stick on backing, runs off 12 volts DC.  Dimable with a standard pot.  Completely noise free forever. 

On Mon, 28 Dec 2015 19:57:39 +0000
Phil <ko6bb1 at gmail.com> wrote:

> OK, rather than clutter up the list with what to many would be OT posts, 
> I decided to wait until I'd bought and tried one (or more) before updating.
> 
> Thanks goes out to all who answered my questions.
> 
> Recap:  I had a 60W equivalent CFL in the floor lamp directly over my 
> operating position.  I'd tried a 100)W equiv one but it was extremely  
> noisy!  Also a couple CFLs in the ceiling lamp.
> 
> This is a floor lamp with a crookneck at the top and a triangular metal 
> shade reminiscent of the old style desk lamps, bulb is horiz to the 
> floor.  I've used it for years and like it because it places the light 
> directly over the operating position work area (keyboard, radios etc).  
> The actual bulb was about 4.5 inches from the front of the Softrock SDR 
> receiver (in a plastic case), with the base of the lamp (where the 
> electronics are) about 7.5 inches (somebody asked about the distances).
> 
> This coupled a LOT of RFI directly into the SDR, visible on the 
> waterfall.  For best results when recording and having the light on I'd 
> slip a 60W incandescent lamp in place of the CFL.  The lamp is also 
> about 16 inches above the operating table, and when listening to ANY 
> portable radio on the table, if it was in the AM or Longwave band and 
> using the built in loopstick antenna got a LOT of RFI from the lamp 
> (unless the lamp was off ;-)
> 
> So today I went down to Lowes (we have a Costco, but I don't have a 
> card) and looked at their LED lamp offerings.  As I expected they had a 
> large variety of them, from a low cost 3 pack for ~$9.00 for 60W units 
> to about $18.00 or so each (Sylvania).  From what I read here I wanted 
> to avoid the REALLY cheap ones as some reported them to be 'noisy'.  
> Also, I wanted to put a 75W equivalent unit in the one over the 
> operating position, and a pair of 100W equivalent units in the ceiling 
> lamp. All three had CFLs, and if I walked around the radio room with a 
> portable radio and the ceiling lamp on I could hear it's 'hash' anywhere 
> in the room. . .
> 
> The ones I settled on were a brand I'd never heard of, "UtiliTech Pro" 
> soft white.  75W for the bench and 2 100W ones for the ceiling.  They 
> were what I'd call "mid-priced", $8.98 for the 75W and $9.98 for the 
> 100W ones.
> Specs:
> 75 W one draws 12W and gives 1100 Lumens.
> 100W one draws 16.5W and gives 1600 Lumens (the pair in the ceiling 
> should then be 3200 Lumens if I calculated right).
> 
> How low is the RFI to my Radios?
> 
> 75W one over the bench:
>    NO trace from the lamp electronics visible in the SDR waterfall at 
> all.  With a portable radio on the bench-top, NO audible RFI. Put a 
> portable radio up to the "bulb" part (light area) and with no station 
> tuned in can't hear ANY RFI.  Move the portable to the base area of the 
> lamps there is SOME RFI, but I won't be putting the radio that close to 
> the lamp, move it a couple inches away and the noise disappears.
> 
> 100W ones in the ceiling lamp, NO audible RFI in the portable when 
> walking around the room, RFI just barely perceptible right next to the 
> light wall switch that turns the lamp on, again, audible IF I put the 
> radio right up to the base of the lamps, not a likely real-world scenario!
> 
> Upshot?  Based on the sample of three that I bought and the almost 
> non-existant RFI from them I'd consider the UtiliTech Pro lamps to be a 
> good product and suitable for use in the radio room.  I consider them 
> good value for the ~$30.00 I spent for three.
> 
> -- 
> 73 de Phil,  KO6BB
> http://www.qsl.net/ko6bb/  (Web Page)
> 
> PRESENT RADIOS:
> Grundigs:    S-350 (~2006), G6 (2011) & S450DLX (2014).
> HOMEBREW:    7 Tube+Rect Regenerative RX for LF (built 2015)
> Icom:        IC-735 Transceiver (~1990).
> Icom:        R-75 With Cascaded 250 & 125Hz CW Filters. (~2005)
> Icom:        IC-7200 Transceiver (~2015).
> Radio Shack: DX-380 digital portable (~1990).
> SDR:         Softrock Ensemble II LF (built from a kit 2015).
> Zenith:      Royal-7000 Transoceanic Portable (~1968).
> 
> ACCESSORIES: HOMEBREW LF-MF Pre-Amp, MFJ-993B HF Auto-Tuner.
>               HOMEBREW 8 Hz Audio Filter.
> 
> ANTENNAS:  88 foot Long Ladder-line fed dipole at 35 feet AGL for MW/SW.
>             HOMEBREW Active Mini-Whip at 36 Feet AGL for LF/MW/SW.
>             HOMEBREW 37 foot "Low Noise Vertical" at 11 feet AGL for LF/MW/SW.
> 
> Merced, Central California, 37, 18, 37N   120, 30, 6W CM97rh
> 
> 
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-- 
73,  Frank