Posts Tagged ‘LED lights’

LED Lights In The Shack

The following blog was originally published in 2016 but is still relevant today.

Utilitech Pro Soft White LED Bulb

A recent posting by Phil, KO6BB, to Yahoo Group's ndblist, described his recent search for some LED lamps to replace the CFL's in his shack / radio workbench area. If you have been wondering how much RFI that LED lamps might be producing, you may find Phil's findings of some value.








"Recap  

I had a 60W equivalent CFL in the floor lamp directly over my operating position. I'd tried a 100W 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-existent 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."

If you have tested anything similar (other brands / models), please let me know and I will add it to Phil's helpful information.

KO6BB's website can be found here, along with some of his homebrew equipment.

A Second West Coast Lightwave Adventure

51km Path courtesy: https://www.google.ca/maps

Toby, VE7CNF, successfully inaugurated his lightwave station earlier this week, on Monday night, completing a nice two-way CW contact between West Vancouver (CN89) and Mayne Island (CN88). The distance spanned was approximately 51km (32 miles), crossing atop the western edges of Vancouver and then across the Strait of Georgia, the body of water separating mainland BC from Vancouver Island.


The details of Toby's homebrew lightwave equipment are described on his web site here and are similar to the station at this end ... also described in earlier blogs. This was the same path covered in my two previous lightwave QSO's with Markus, VE7CA, described here.

Monday evening's weather was clear and calm but at this time of the year, true darkness is a long time coming. With a full-moon just a few nights away, the sky never did get very dark it seemed. I set up my end of the path late in the afternoon, just in front of the house.


            VE7CNF/7 end showing the busy-looking site in operation.



Accompanying Toby to the mountain lookout location were VA7MM, his YL VA7MAY and Markus, VE7CA who initially scouted out and found this nice site for our original lightwave contacts. Thanks to Markus who snapped a picture of the diehard lightwave crew!

VA7MM, VA7MAY and VE7CNF
One thing that I noticed on Monday night was the very loud QRM coming from the sodium vapor lighting used on the ski hills just above Toby's location. The resolution of my Fresnel lens was just not sharp enough to be able to isolate Toby clearly without also being saturated with the lighting noise ... from my end, the ski-hill lighting appeared just above his deep-red LED.

Although Toby's signal was very strong, the lighting hum was strong enough to cause some receiver front-end desensing and slightly modulate Toby's CW signal with a touch of AC ripple. I did not notice this hum when working VE7CA at the same location a couple of years ago. It's possible that there was no snow on the ski-hill at the time and the lights were not turned on.


Moving the receiver just a few degrees to the west made a huge difference, as the hummy background noise level returned to the quiet hush of a dark sky.

Toby's recording of my signal is much cleaner as there are no bright lights when looking towards Mayne Island. It is really interesting to hear the rapid fading, almost a flutter, on my CW signal, as the light passes through various levels of ever-changing haze above the water.


Midway through our one hour QSO, Toby reported that my signal had dropped measurably as had his signal on my end. Although I could see no obvious clouds in the path, I did notice a red glow out in the Strait that had not been there earlier. When I turned off my transmitter, the glow disappeared, indicating that there was indeed some low level haze that had crept up on us, and enough to cause some signal absorption on the path. Thankfully signal levels returned to normal, and actually were a bit stronger, about fifteen minutes later, when the haze thinned and the skies had grown a little darker.

Towards the end of our QSO, I had the chance to test out my #2 receiver. It was built so that I could do some NLOS cloudbounce testing here on the island, without having to separate my main system's transmitter/receiver pairing. At the time, there were no lenses available from the overseas manufacturer, so my quest for a suitable lens led me to a local 'bargain style' hardware importer (Princess Auto), who had a good supply of $5 lenses. The lens seemed to function well in my local tests but it had never been put side-by-side with the higher quality lens in my main transceiver. As it turned out, the $5 lens worked very well, easily detecting the 51km signal although it didn't sound quite as loud since the receiver I built for it was intended to interface with my laptop and lacked the additional audio amp I had built for the main system.

A final interesting observation was made, when on a whim, I placed a large cardboard shield over the bottom quarter of the transceiver's receiver lens. The signal strength didn't appear to change at all. I gradually blocked more and more of the lens but astonishingly, was still able to copy Toby's CW with all but a 1" strip of the lens completely covered! This would tend to indicate that we would be able to communicate with a very much smaller Fresnel or optical glass lens, such as a 4" or even a 2" inch magnifier. As I commented to Toby on CW, the possibilities for experimentation are endless.

All-in-all it was a very successful evening and the mountain-top gang seemed to enjoy the outing as much as I did, and ... the QSL is in the mail.


Hopefully there are other VE7's in or around Vancouver that might be interested in throwing a signal over this way some night ... I'll leave the light on for ya!

LED Lights In The Shack

Utilitech Pro Soft White LED Bulb


A recent posting by Phil, KO6BB, to Yahoo Group's ndblist, described his recent search for some LED lamps to replace the CFL's in his shack / radio workbench area. If you have been wondering how much RFI that LED lamps might be producing, you may find Phil's findings of some value.






"Recap  

I had a 60W equivalent CFL in the floor lamp directly over my operating position. I'd tried a 100W 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-existent 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."

I don't see these being sold here in Canada but I may be mistaken. If you have tested anything similar (other brands / models), please let me know and I will add it to Phil's helpful information.

KO6BB's website can be found here, along with some of his homebrew equipment.

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