RE: [AMRadio] "Magic" lamp QRM
Slightly off topic: My neighbor has it all. Touch lamps, cordless phones, wireless keypads/mouses, and of course TVs. I get into all of it! Fortunately I can demonstrate NO INTERFERENCE AT MY QTH on anything (filters, toroids etc...). When I handed him printed info on "the how and whys" of RF interference and volunteered to help solve it... He threw the papers to the ground, started to call me &@&@$# and everything else in the book! At that point I stepped back from him and realized that I did not have to (or want to) help him at all. I told him that he could fix it himself and that I'm not legally obligated in any way... especially as long as he acts like that. After his performance, I said: "It's your problem, not mine. I hope you enjoy my conversations." Case closed. However, I did mail him all the info "certified receipt" with his signature so he could do it him self since I will never step into his house again. Fortunately I do not hear any of his crap on my receivers (quad loops help?). Actually... I'm glad he acted like that. Now I know I will not get any more complaints, or have to spend the time with the jerk. George AB2KC 1KW AM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Ed Sieb Sent: Sunday, October 06, 2002 12:48 AM To: amradio@mailman.qth.net Subject: RE: [AMRadio] "Magic" lamp QRM Those lamps are quite sensitive to RF fields. One of my neighbors has one of those wretched things. When he decides to use it, I just fire up the 100W rig, and key up a few random carriers in sequence. That sequences his lamp in varying brightness, and he eventually unplugs the thing in frustration. All my neighbors run RF trash producing junk. I have a contant +20dB over 9 roar of buzzies, warbles, farts and raspy hum all over HF. When ever I key up a nice carrier, I can hear all these signals shift around and settle back to their natural frequencies, when I unkey. It's quite amusing. Sending CW must cause quite some kind of disruption around my neighborhood. I can't wait untill I get my big 1KW big rig online. maybe that'll just blow up all that junk, once and for all. Ed, VA3ES ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] "Magic" lamp QRM
Don, My brother (KAØVEL) has two of those touch lamps. He bought them over 15 years ago and I am surprised they are still sold. We just figured they had SCR's in them. We never tried to suppress the noise, it was easier just to shut them off. We experienced similar noise from the little remote control modules too. John - Original Message - From: "Donald Chester" <[EMAIL PROTECTED]> To: Sent: Saturday, October 05, 2002 5:05 PM Subject: [AMRadio] "Magic" lamp QRM > > I recently noticed a very rough, broad signal that wipes out 30-kc portions > of the spectrum from the middle of the broadcast > band through 10 m. It is especially bad on 160 and 80m. I did a little > sniffing with a portable radio and found the source to be a > table lamp my daughter just bought. The thing doesn't have a conventional > switch, but a metal base, and you turn in on and off > by touching the base with your hand. The thing must have some sort of > oscillator somewhere in the 450 kc range, and works by > detuning the oscillator when you touch it. What kind of rubbish is someone > going to think of next to garbage up the radio > spectrum! > > I have never seen one of these things before. Is this a novelty or > speciality item, or is this the way all table lamps are made these > days? (This was probably the first time in over 20 years since anyone here > brought home a new table lamp.) Surely, this must fall under Part 15, so I > wonder why the FCC even allows those things to be sold on the market. The > noise is far worse than the hash from my computer monitor, and I thought > that was already bad enough. I'm surprised the AM broadcast industry isn't > raising bloody hell about stuff like this. I can't imagine polluting the rf > spectrum with rubbish because someone might be too lazy to flip a switch on > a table lamp. > > I'm wondering if anyone else has had problems with interference from those > things, and what might be the simplest solution. I tried an in-line rf > filter, but it made no improvement whatever. Unless there is something > simple to by-pass, the only solution I can think of is to go into the thing, > rip out the electronics, and mount a conventional swith with a knob on the > base. I'd like to hear form anyone who has successfully fixed one of these > things some way other than clip-leading the power cord across the HV > terminals of the plate transformer and throwing the big switch. > > Don K4KYV > > _ > MSN Photos is the easiest way to share and print your photos: > http://photos.msn.com/support/worldwide.aspx > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] "Magic" lamp QRM
Here ya go Don, for what it's worth, by doing a Google search. Also check the ARRL web page, http://www.arrl.org/tis/info/touchlamp.html for real great info on touch lamp problems, radiation, cures, etc. Pete Also several explanations off the web: How does a "touch lamp" work? -- LAM, Enosburg Falls, VT A touch lamp detects your touch by looking for changes in the electric properties of the lamp's surfaces. It monitors these properties by putting a fluctuating electric charge on them. As electric current flows toward the bulb through the lamp's wires, it passes through an electronic device that places a high frequency (about 60 kHz) alternating current onto those wires. This added current causes the lamp's surfaces to take on a small fluctuating electric charge--first positive, then negative, then positive, over and over again. This surface charging involves electrostatic forces, which extend long distances between charged objects, and occurs even though the lamp's surfaces aren't directly connected to the lamp's wires. The more surface the lamp has, the more easily it can hold that electric charge--the greater the lamp's electric capacitance. When you plug the lamp in, the electronic device uses its fluctuating charge to determine how easy it is to add or subtract charge from the lamp's surfaces. In other words, it measures the lamp's capacitance. It then begins to look for changes in that capacitance. When you touch the lamp, or even come close to its surfaces, your body effectively adds to the lamp's surface and its capacitance increases significantly. The electronic device detects this increase in capacitance and switches the lamp's state from on to off or from off to on. The fact that you don't have to touch the lamp to affect its capacitance means that a touch lamp can have insulating paint on its metal surfaces yet still detect your touch. You can also buy touch lamp modules that plug into the wall and turn the lamp that's connected to them into a touch lamp. These modules are so sensitive to capacitance changes in the lamp that you can trigger them just by touching the lamp cord. Date: Tue Apr 21 15:11:47 1998 Posted By: William Beaty, Electrical Engineer / Physics explainer / K-6 science textbook content provider Area of science: Engineering ID: 891020878.Eg Message: Hi Luke! Touch-lamps are misleading because they seem so simple, but the electronic circuitry inside them is pretty complicated. It's not as complex as a television or computer, its something like an inexpensive radio. Get ready, because the explanation isnt going to be brief! (grin!) The touch lamp has several main parts: A metal antenna touch-sense circuitry flip-flop memory bit low-voltage power supply high-voltage electronic switch Light bulb A touch-lamp is interesting because it uses a combination of "static electricity" and electric current to sense your touch. Antenna The metal shell of the lamp is the antenna. The touch-sense circuitry works by giving the antenna a positive charge imbalance and then a negative one. It does this over and over very rapidly, so positive and negative voltages appear on the metal shell of the lamp. In other words, the outside of the lamp has vibrating static electricity on its surface. ( Its not "static" and unmoving. Yet its the same stuff as "static electricity.") The vibrating charge is very feeble, its far too weak to make sparks. But it can be measured. As the touch-sense circuitry moves charge into and out of the antenna, it measures the tiny flow of charge in the conductor leading to the antenna. As long as nobody is touching the antenna, this flow of charge always is less than a particular value. (It's probably a few microamperes of alternating current, millionths of amps.) If you touch the metal lamp shell with your finger, the touch-sense circuitry has to work harder. It isnt just sending charge in and out of the metal lamp anymore. Now it has to electrify your whole body too. Your body has a much larger surface than the lamp, so it takes a much larger amount of charge. When you touch the lamp, the circuitry detects the higher current going to the anteanna. It then sends a signal to the memory circuit below, which causes the lamp to switch from off to on (or vice versa.) Memory bit The lamp contains a pair of electronic switches which control each other. Their function is to "remember" whether the lamp is supposed to stay on or off. Together they are called a binary flip flop, and they act as a single memory bit just like that in a computer. When the touch-sense circuitry gives them a signal, they "flip" one way and send a signal to turn the light bulb on. When the touch-sense circuitry gives them a second signal, they "flip" the other way and tell the light bulb to turn off. High voltage, High current switch The lamp has one big transistor in it which controls the light bulb. This electronic switch can withstand dangerous amounts of voltage (120volts from th
RE: [AMRadio] "Magic" lamp QRM
From: "Ed Sieb" <[EMAIL PROTECTED]> ... One of my neighbors has one of those wretched things. When he decides to use it, I just fire up the 100W rig, and key up a few random carriers in sequence. That sequences his lamp in varying brightness, and he eventually unplugs the thing in frustration. Ours emits noise even when it is turned off! The only way to kill it is to unplug it. Don _ Send and receive Hotmail on your mobile device: http://mobile.msn.com
RE: [AMRadio] "Magic" lamp QRM
Those lamps are quite sensitive to RF fields. One of my neighbors has one of those wretched things. When he decides to use it, I just fire up the 100W rig, and key up a few random carriers in sequence. That sequences his lamp in varying brightness, and he eventually unplugs the thing in frustration. All my neighbors run RF trash producing junk. I have a contant +20dB over 9 roar of buzzies, warbles, farts and raspy hum all over HF. When ever I key up a nice carrier, I can hear all these signals shift around and settle back to their natural frequencies, when I unkey. It's quite amusing. Sending CW must cause quite some kind of disruption around my neighborhood. I can't wait untill I get my big 1KW big rig online. maybe that'll just blow up all that junk, once and for all. Ed, VA3ES
Re: [AMRadio] "Magic" lamp QRM
Don: I remember several years ago about some company that designed a lamp like that, but don't remember all the particulars. Back in the 80's I had a friend that had a lamp that the switch was touch sensitive, and if my memory serves right it was an add in device that screwed into the base of the lamp then the bulb screwed into the device. You would leave the switch turned on and it sensed the touch of your hand to the base of the lamp. There was also some company that developed a bulb that ran in the 14 meg region. Could this lamp be something one of the companies shelved years ago and now has redesigned and/or reintroduced or do you have any additional information about it? It seems the price of the lamp that had that kind of switch integrated was so expensive that they didn't sell many so it disappeared from the shelves. I don't remember the frequency of the thing but thought it was higher than you reported. Again if I remember right, the cap effect of your hand on the lamp base changed frequency of the oscillator in it which caused the lamp to go off/on. Sorry I don't remember who built or sold them, sadly it has been too many years. 73 Jim de W5JO > > I recently noticed a very rough, broad signal that wipes out 30-kc portions > of the spectrum from the middle of the broadcast > band through 10 m. It is especially bad on 160 and 80m. I did a little > sniffing with a portable radio and found the source to be a > table lamp my daughter just bought. The thing doesn't have a conventional > switch, but a metal base, and you turn in on and off > by touching the base with your hand. The thing must have some sort of > oscillator somewhere in the 450 kc range, and works by > detuning the oscillator when you touch it. What kind of rubbish is someone > going to think of next to garbage up the radio > spectrum! > > I have never seen one of these things before. Is this a novelty or > speciality item, or is this the way all table lamps are made these > days? (This was probably the first time in over 20 years since anyone here > brought home a new table lamp.) Surely, this must fall under Part 15, so I > wonder why the FCC even allows those things to be sold on the market. The > noise is far worse than the hash from my computer monitor, and I thought > that was already bad enough. I'm surprised the AM broadcast industry isn't > raising bloody hell about stuff like this. I can't imagine polluting the rf > spectrum with rubbish because someone might be too lazy to flip a switch on > a table lamp. > > I'm wondering if anyone else has had problems with interference from those > things, and what might be the simplest solution. I tried an in-line rf > filter, but it made no improvement whatever. Unless there is something > simple to by-pass, the only solution I can think of is to go into the thing, > rip out the electronics, and mount a conventional swith with a knob on the > base. I'd like to hear form anyone who has successfully fixed one of these > things some way other than clip-leading the power cord across the HV > terminals of the plate transformer and throwing the big switch. > > Don K4KYV
