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C. Crane's Twin Ferrite Antenna
I bought this antenna on a 30 day trial, and just got it about 12 hours ago.
So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. The antenna consists of three parts: a 600-1800 KHz control dial, a ferrite antenna and something called the antenna element. The latter is about 8" long by 3" by 1.5" (high). The idea is that one puts the ferrite antenna very near the radio and the antenna element in some other spot, then adjusts the control dial to the max strength. I detect zero change in any AM signal from the (C. Crane) radio anywhere on the dial. The antenna element can be grounded. I modestly did this by hooking a wire (alligator clips) from the element to the ground socket of an AC outlet (nail in the socket). No change. BTW, when I was doing the experiment last evening, the signal was pretty decent during that period. In fact, quite listenable. All this without the device though. I'll continue to experiment, but so far not so good. Comments? -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
On Tue, 29 Nov 2005 11:36:09 GMT, "W. Watson"
wrote: excerpted... I'll continue to experiment, but so far not so good. Comments? You've already got an 8" ferrite bar antenna in the C.Crane radio; perhaps the twin-doozie deal just doesn't add that much. bob k5qwg |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. Why do you think that's a radio problem? :-) -- 73, Cecil http://www.qsl.net/w5dxp |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. The antenna consists of three parts: a 600-1800 KHz control dial, a ferrite antenna and something called the antenna element. The latter is about 8" long by 3" by 1.5" (high). The idea is that one puts the ferrite antenna very near the radio and the antenna element in some other spot, then adjusts the control dial to the max strength. I detect zero change in any AM signal from the (C. Crane) radio anywhere on the dial. The antenna element can be grounded. I modestly did this by hooking a wire (alligator clips) from the element to the ground socket of an AC outlet (nail in the socket). No change. BTW, when I was doing the experiment last evening, the signal was pretty decent during that period. In fact, quite listenable. All this without the device though. I'll continue to experiment, but so far not so good. Comments? I'd change the power supply to a better brand. Generally if you have atmospheric or man-made noise increasing the antenna efficiency is just going to increase the noise along with the signal. You could try to make a directional antenna; this would increase your desired signal more than your noise. The antenna would have to be big, however. The wavelength at 800kHz is somewhere around 370 meters and you'd need to use around 1/4 of this. You could try to feed power supply noise to the radio antenna at just the right amplitude and phase to null it out. This would be a good subject for an undergraduate or even a Master's thesis in EE but probably not a good thing to do in practice. You could attempt to shield it. Rat Shack has some clamp-on ferrites, you could put one of these on your power cord close to the end that plugs into the power supply. You could also make sure that the PC case is well shielded. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
C. Crane's Twin Ferrite Antenna
On Tue, 29 Nov 2005 11:36:09 GMT, W. Watson wrote:
I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. The 'noise' is _also_ a signal -- just one that nobody wants to receive. The "C. Crane's Twin Ferrite Antenna" happily 'improves' the reception of the noise -- in addition to the signal(s) you desire. Let me guess: That PSU was "Made in China". Jonesy -- Marvin L Jones | jonz | W3DHJ | linux Pueblo, Colorado | @ | Jonesy | OS/2 __ 38.24N 104.55W | config.com | DM78rf | SK |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. Any rf noise put out by the computer ps is going to be picked up by your antenna as well as the radio station you are trying to hear. So a better antenna (if your new one is indeed better) wil just pick up stronger power supply noise. It's moslty a null situation. What you need to do is get that power supply fixed or replaced - 73 de Mike KB3EIA - |
C. Crane's Twin Ferrite Antenna
"Tim Wescott" bravely wrote to "All" (29 Nov 05 09:16:58)
--- on the heady topic of " C. Crane's Twin Ferrite Antenna" TW From: Tim Wescott TW Xref: core-easynews rec.radio.amateur.antenna:220543 [,,,] TW Generally if you have atmospheric or man-made noise increasing the TW antenna efficiency is just going to increase the noise along with the TW signal. TW You could try to make a directional antenna; this would increase your TW desired signal more than your noise. [,,,] I wonder if it would help putting up a short vertical and summing its signal with such polarity that it cancels the noise from the main directive antenna? This on the theory that most man-made noise is by its nature vertically polarized. A*s*i*m*o*v .... If you're not making waves, you're not rowing the boat |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
I'll continue to experiment, but so far not so good. Comments? As others have said, you should try to attenuate the noise at its source. If it is radiated, you need a better PSU. If it is coming out on the PCs AC line, line filters might help. If the PC and KGO are not in the same direction, some sort of directional antenna might help. Of course, the ultimate solution would be to move to SF and get a really big signal. But there are problems with that, too: I live abt 3-4 miles west of KNX (50 KW, 1070 KHz) and my problem is avoiding it, not making it stonger :) Phil |
C. Crane's Twin Ferrite Antenna
"Tim Wescott" wrote in message ... W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. The antenna consists of three parts: a 600-1800 KHz control dial, a ferrite antenna and something called the antenna element. The latter is about 8" long by 3" by 1.5" (high). The idea is that one puts the ferrite antenna very near the radio and the antenna element in some other spot, then adjusts the control dial to the max strength. I detect zero change in any AM signal from the (C. Crane) radio anywhere on the dial. The antenna element can be grounded. I modestly did this by hooking a wire (alligator clips) from the element to the ground socket of an AC outlet (nail in the socket). No change. BTW, when I was doing the experiment last evening, the signal was pretty decent during that period. In fact, quite listenable. All this without the device though. I'll continue to experiment, but so far not so good. Comments? I'd change the power supply to a better brand. Generally if you have atmospheric or man-made noise increasing the antenna efficiency is just going to increase the noise along with the signal. You could try to make a directional antenna; this would increase your desired signal more than your noise. The antenna would have to be big, however. The wavelength at 800kHz is somewhere around 370 meters and you'd need to use around 1/4 of this. The ferrite antennas are already directional. That is one of their advantages. You could try to feed power supply noise to the radio antenna at just the right amplitude and phase to null it out. This would be a good subject for an undergraduate or even a Master's thesis in EE but probably not a good thing to do in practice. These devices are well known and sold at least by 2 ham manufacturers- MFJ and Timewave(?). Dale W4OP |
C. Crane's Twin Ferrite Antenna
Cecil Moore wrote:
W. Watson wrote: Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. Why do you think that's a radio problem? :-) When I turn the computer off, the radio station noise drops dramatically. It doesn't matter if I use AC or DC. I can detect the large noise change in my car from the garage. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
Tim Wescott wrote:
W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles .... snip during that period. In fact, quite listenable. All this without the device though. I'll continue to experiment, but so far not so good. Comments? I'd change the power supply to a better brand. Generally if you have atmospheric or man-made noise increasing the antenna efficiency is just going to increase the noise along with the signal. You could try to make a directional antenna; this would increase your desired signal more than your noise. The antenna would have to be big, however. The wavelength at 800kHz is somewhere around 370 meters and you'd need to use around 1/4 of this. You could try to feed power supply noise to the radio antenna at just the right amplitude and phase to null it out. This would be a good subject for an undergraduate or even a Master's thesis in EE but probably not a good thing to do in practice. You could attempt to shield it. Rat Shack has some clamp-on ferrites, you could put one of these on your power cord close to the end that plugs into the power supply. You could also make sure that the PC case is well shielded. I tried the RS ferrites and they made no change. I even took barbell weights and put them on the AC line of the PC. Zippo. If I hadn't already spent $60 for the new PSU six weeks ago, I might think of buying a much better one. In some way this may be circuit dependent. I do believe I plugged in my other PC to the same socket and had the same experience; however, when it's plugged into its normal socket, there is no noticeable change. Interestingly, bad weather moved in yesterday and today, and reception from the station has been quite good with the normal antenna. This stuff can get pretty strange. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
Allodoxaphobia wrote:
On Tue, 29 Nov 2005 11:36:09 GMT, W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. The 'noise' is _also_ a signal -- just one that nobody wants to receive. The "C. Crane's Twin Ferrite Antenna" happily 'improves' the reception of the noise -- in addition to the signal(s) you desire. Let me guess: That PSU was "Made in China". Jonesy Yes, you absolutely guessed the right country. I called the tech support and they were less than useful. I asked about a circuit diagram. Sorry, we don't have one to give out. The trick here is that I see absolutely no change at all. One would think maybe the volume might increase, but nay. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
Michael Coslo wrote:
W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. Any rf noise put out by the computer ps is going to be picked up by your antenna as well as the radio station you are trying to hear. So a better antenna (if your new one is indeed better) wil just pick up stronger power supply noise. It's moslty a null situation. What you need to do is get that power supply fixed or replaced - 73 de Mike KB3EIA - I think the only solutions to the PSU problem is to buy a much better one. As I mention above, that's probably a losing proposition. I doubt after 6 weeks they would take it back. It might be worth a try though. Note my comment above to someone a few moments ago that this seems to be a household circuit dependent problem. Another PC in the same room works fine until I plug it into the socket that I first noticed the problem. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
Phil Wheeler wrote:
W. Watson wrote: I'll continue to experiment, but so far not so good. Comments? As others have said, you should try to attenuate the noise at its source. If it is radiated, you need a better PSU. If it is coming out on the PCs AC line, line filters might help. If the PC and KGO are not in the same direction, some sort of directional antenna might help. Of course, the ultimate solution would be to move to SF and get a really big signal. But there are problems with that, too: I live abt 3-4 miles west of KNX (50 KW, 1070 KHz) and my problem is avoiding it, not making it stonger :) Phil Yes, I've had that experience with close stations. You can probably listen to it through the bed springs. :-) Attempts to shield the AC with the RS ferrite block and a barbell weight failed. See comment about household circuit dependency in my just posted responses above yours. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
In some way this may be circuit dependent. I do believe I plugged in my other PC to the same socket and had the same experience; however, when it's plugged into its normal socket, there is no noticeable change. Grounding issue? |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
Phil Wheeler wrote: W. Watson wrote: I'll continue to experiment, but so far not so good. Comments? As others have said, you should try to attenuate the noise at its source. If it is radiated, you need a better PSU. If it is coming out on the PCs AC line, line filters might help. If the PC and KGO are not in the same direction, some sort of directional antenna might help. Of course, the ultimate solution would be to move to SF and get a really big signal. But there are problems with that, too: I live abt 3-4 miles west of KNX (50 KW, 1070 KHz) and my problem is avoiding it, not making it stonger :) Phil Yes, I've had that experience with close stations. You can probably listen to it through the bed springs. :-) I hope not: Still use a water bed :) Attempts to shield the AC with the RS ferrite block and a barbell weight failed. See comment about household circuit dependency in my just posted responses above yours. Got it! |
C. Crane's Twin Ferrite Antenna
On Wed, 30 Nov 2005 02:54:34 GMT, "W. Watson"
wrote: Interestingly, bad weather moved in yesterday and today, and reception from the station has been quite good with the normal antenna. This stuff can get pretty strange. Classic indication of a bad ground, or a ground loop. 73's Richard Clark, KB7QHC |
C. Crane's Twin Ferrite Antenna
In article t,
W. Watson wrote: I tried the RS ferrites and they made no change. I even took barbell weights and put them on the AC line of the PC. Zippo. If I hadn't already spent $60 for the new PSU six weeks ago, I might think of buying a much better one. Ferrites clamped around the power cable will help with common-mode RF noise. They won't do anything to help cancel out differential-mode noise. It'd probably be beneficial for you to try to get a robust powerline noise filter. These will filter out both common-mode noise, and differential noise as well. Unfortunately, it's possible that the new power supply is radiating RF directly, rather than feeding it back into the mains. If so, nothing other than replacing it, or switching to a PC case with better shielding, is likely to help the problem. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
C. Crane's Twin Ferrite Antenna
Richard Clark wrote:
On Wed, 30 Nov 2005 02:54:34 GMT, "W. Watson" wrote: Interestingly, bad weather moved in yesterday and today, and reception from the station has been quite good with the normal antenna. This stuff can get pretty strange. Classic indication of a bad ground, or a ground loop. 73's Richard Clark, KB7QHC If so, how do I track it down? -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
Michael Coslo wrote: W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. Any rf noise put out by the computer ps is going to be picked up by your antenna as well as the radio station you are trying to hear. So a better antenna (if your new one is indeed better) wil just pick up stronger power supply noise. It's moslty a null situation. What you need to do is get that power supply fixed or replaced - 73 de Mike KB3EIA - I think the only solutions to the PSU problem is to buy a much better one. As I mention above, that's probably a losing proposition. I doubt after 6 weeks they would take it back. It might be worth a try though. Note my comment above to someone a few moments ago that this seems to be a household circuit dependent problem. Another PC in the same room works fine until I plug it into the socket that I first noticed the problem. Hmmm, just maybe, you might be able to ditch it as a warranty item. Dunno tho' as it will depend on the outfit that sold it to you. I don't know if you are a Ham or not, but if you are, you might play the part 15 card, as they are required to not interfere. I suspect that a 160 meter rig might catch the same interference. It is kind of a drag though, since IIRC a noisy switcher Power supply is hard to fix. Good luck! - 73 de Mike KB3EIA - |
C. Crane's Twin Ferrite Antenna
On Wed, 30 Nov 2005 03:02:10 GMT, "W. Watson"
wrote: Phil Wheeler wrote: W. Watson wrote: I'll continue to experiment, but so far not so good. Comments? As others have said, you should try to attenuate the noise at its source. If it is radiated, you need a better PSU. If it is coming out on the PCs AC line, line filters might help. If the PC and KGO are not in the same direction, some sort of directional antenna might help. Of course, the ultimate solution would be to move to SF and get a really big signal. But there are problems with that, too: I live abt 3-4 miles west of KNX (50 KW, 1070 KHz) and my problem is avoiding it, not making it stonger :) Phil Yes, I've had that experience with close stations. You can probably listen to it through the bed springs. :-) Attempts to shield the AC with the RS ferrite block and a barbell weight failed. See comment about household circuit dependency in my just posted responses above yours. Wayne, You may wish to get one of those $5 circuit analyzers from your local Lowe's/Home Depot/Tools R Us (yes, I realize this probably means a drive to Grass Valley) and check for open ground connections on all your sockets. I had grounding issues at my home and after getting a shock while adjusting the hot water in the shower brought in an electrician. He found many problems such as the hot and return shorting on the bathtub (behind the wall of course where it can't be seen) and most of my outlets did not have a ground. Had the house re-wired and it got a bit more RF friendly - hope you find your issue and don't have to rewire the house. BTW, Nevada City is a nice place to call home - if you bump into Mayor Arnett tell him that Howard from LA says hi. Howard |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
Cecil Moore wrote: Why do you think that's a radio problem? :-) When I turn the computer off, the radio station noise drops dramatically. It doesn't matter if I use AC or DC. I can detect the large noise change in my car from the garage. That sounds like a computer problem, not a radio problem. What am I missing? -- 73, Cecil http://www.qsl.net/w5dxp |
C. Crane's Twin Ferrite Antenna
Dave Platt wrote:
In article t, W. Watson wrote: I tried the RS ferrites and they made no change. I even took barbell weights and put them on the AC line of the PC. Zippo. If I hadn't already spent $60 for the new PSU six weeks ago, I might think of buying a much better one. Ferrites clamped around the power cable will help with common-mode RF noise. They won't do anything to help cancel out differential-mode noise. Differential mode radiation is almost never a problem in situations like this. The differential mode component of the noise, by definition, is from equal and opposite noise currents on the two conductors (of the power line, for example). For this mode, the conductors comprise a transmission line, and radiation will be extremely small because the fields from the two very close and parallel conductors are equal in magnitude and opposite in direction. Ferrites are a good suggestion, but the ones commonly used for RFI suppression are of a ferrite type which doesn't have an awful lot of attenuation as low as the AM broadcast band. Best would be some Fair-Rite 70 series, or other ferrite with an initial permeability of several thousand. Best would be to get a large core and wrap multiple turns on it with the power cord, as close to the PC as possible. This way, you get a lot more impedance than clamping cores onto the wire, since the impedance is proportional to the square of the number of turns. That is, 10 turns on a single core gives you the same impedance as 100 of the same cores clamped onto the cable. It'd probably be beneficial for you to try to get a robust powerline noise filter. These will filter out both common-mode noise, and differential noise as well. A good power line filter isn't a bad idea, but differential mode filtering won't make any appreciable difference. Unfortunately, it's possible that the new power supply is radiating RF directly, rather than feeding it back into the mains. If so, nothing other than replacing it, or switching to a PC case with better shielding, is likely to help the problem. To radiate any significant amount of energy requires some sort of antenna, so a power supply won't radiate much on its own. The trick, then, is to prevent the noise from getting from its source to the antenna. The most likely antenna is the power line, but any other wires connected to the computer can also serve this function. I'd start by disconnecting everything from the computer except the power line, getting the noise down with ferrites or a power line filter, then connecting one thing at a time and applying ferrites to the other wires as required. If wires inside the computer are acting as the antenna, the computer box should contain the noise to a high degree -- if you still have noise with only the power line connected and filtered, check the integrity of the computer case. Look for any seams that don't have good metal-to-metal contact between pieces. Roy Lewallen, W7EL |
C. Crane's Twin Ferrite Antenna
On Wed, 30 Nov 2005 03:44:17 GMT, "W. Watson"
wrote: If so, how do I track it down? Hi OM, You have already related other experience where you shared the same circuit as a noisy source (sharing the same circuit is easily identifiable as being on the same breaker). Moving to another circuit can be a solution. If it provides relief, then noise was coming by conduction (through the wires) rather than radiation (over the air). Insofar as your specific weather related symptoms, this is usually related to a loose and corroded ground connection. The first place to start is with your panel's service ground. If you have other ground rods, then check them and INSURE they are also connected to the service ground. In your shack, do not daisy-chain grounds - use a star configuration. However, you will probably still have mixed grounds with equipment interconnections (and some of them are obvious and in your face and are still invisible). That is OK if you also have the individual equipments grounded in that star configuration. One of those invisible gotchas is the equipment interface to a computer, with a dial-up modem, its connection to the phone line and its own ground (if in fact it exists). This ground path is one you stare at every day and never see - unless lightning is looking for ground in through it and into your shack. To "track it down" requires that you pull every plug, break every breaker and listen (you will need a battery powered, ungrounded receiver that exhibits the problem to do this). Replace each one at a time until you re-achieve your problem - take one step back and focus there. 73's Richard Clark, KB7QHC |
C. Crane's Twin Ferrite Antenna
Mike Coslo wrote:
W. Watson wrote: Michael Coslo wrote: W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. Any rf noise put out by the computer ps is going to be picked up by your antenna as well as the radio station you are trying to hear. So a better antenna (if your new one is indeed better) wil just pick up stronger power supply noise. It's moslty a null situation. What you need to do is get that power supply fixed or replaced - 73 de Mike KB3EIA - I think the only solutions to the PSU problem is to buy a much better one. As I mention above, that's probably a losing proposition. I doubt after 6 weeks they would take it back. It might be worth a try though. Note my comment above to someone a few moments ago that this seems to be a household circuit dependent problem. Another PC in the same room works fine until I plug it into the socket that I first noticed the problem. Hmmm, just maybe, you might be able to ditch it as a warranty item. Dunno tho' as it will depend on the outfit that sold it to you. I don't know if you are a Ham or not, but if you are, you might play the part 15 card, as they are required to not interfere. I suspect that a 160 meter rig might catch the same interference. It is kind of a drag though, since IIRC a noisy switcher Power supply is hard to fix. Good luck! - 73 de Mike KB3EIA - I'm tempted, but somehow your message gave me another idea. I think I'm going to take the PC to an entirely different location miles from here and see if get the same problem. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
Howard wrote:
On Wed, 30 Nov 2005 03:02:10 GMT, "W. Watson" wrote: Phil Wheeler wrote: W. Watson wrote: I'll continue to experiment, but so far not so good. Comments? As others have said, you should try to attenuate the noise at its source. If it is radiated, you need a better PSU. If it is coming out on the PCs AC line, line filters might help. If the PC and KGO are not in the same direction, some sort of directional antenna might help. Of course, the ultimate solution would be to move to SF and get a really big signal. But there are problems with that, too: I live abt 3-4 miles west of KNX (50 KW, 1070 KHz) and my problem is avoiding it, not making it stonger :) Phil Yes, I've had that experience with close stations. You can probably listen to it through the bed springs. :-) Attempts to shield the AC with the RS ferrite block and a barbell weight failed. See comment about household circuit dependency in my just posted responses above yours. Wayne, You may wish to get one of those $5 circuit analyzers from your local Lowe's/Home Depot/Tools R Us (yes, I realize this probably means a drive to Grass Valley) and check for open ground connections on all your sockets. I had grounding issues at my home and after getting a shock while adjusting the hot water in the shower brought in an electrician. He found many problems such as the hot and return shorting on the bathtub (behind the wall of course where it can't be seen) and most of my outlets did not have a ground. Had the house re-wired and it got a bit more RF friendly - hope you find your issue and don't have to rewire the house. BTW, Nevada City is a nice place to call home - if you bump into Mayor Arnett tell him that Howard from LA says hi. Howard Ah, you know about us. I'm not a ham, but I will be speaking to our local club in January about radio astronomy. I used to have my hair cut by the former mayor. I'll have to ask my present barber if he frequents her shop. Maybe he attends the ham meetings. I only go to them when I want to promote RA, which has been 3 times. Although I went a few weeks ago to find out if anyone had a Icom R7000 rcvr. No luck. However, my opportunity to buy one disappeared within a few days of that meeting. I may have one of those analyzers here somewhere. Lowe's is a long way from here, but we have one very good hardware store that would be a good candidate. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
Cecil Moore wrote:
W. Watson wrote: Cecil Moore wrote: Why do you think that's a radio problem? :-) When I turn the computer off, the radio station noise drops dramatically. It doesn't matter if I use AC or DC. I can detect the large noise change in my car from the garage. That sounds like a computer problem, not a radio problem. What am I missing? Probably nothing. However, I'd be willing to bet that I wouldn't have this problem if I were 100 miles closer to the radio station. The Crane device has been so ineffective its baffling as an issue aside from the one about my radio. I built an FM signal booster when I was 14 that showed more promise. Well, I've got 28 more days to return it. If it shows nothing more, I will be out about $7.00 for return postage--rental fee? -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
W. Watson wrote:
Cecil Moore wrote: W. Watson wrote: Cecil Moore wrote: Why do you think that's a radio problem? :-) When I turn the computer off, the radio station noise drops dramatically. It doesn't matter if I use AC or DC. I can detect the large noise change in my car from the garage. That sounds like a computer problem, not a radio problem. What am I missing? Probably nothing. However, I'd be willing to bet that I wouldn't have this problem if I were 100 miles closer to the radio station. Absolutely. If the station signal is relatively stronger than the computer noise, the computer's RFI will not be so much an issue. Right now, they are about the same strength. Moving the computer will probably help a lot. Just out of curiosity, what is the frequency of the station you are trying to recieve? And while we are at it, is the noise on the radio in just one spot, or is it on pretty much the whole band? - 73 de Mike KB3EIA - |
C. Crane's Twin Ferrite Antenna
On Wed, 30 Nov 2005 13:26:37 GMT, "W. Watson"
wrote: W. Watson wrote: I'll continue to experiment, but so far not so good. Comments? I would like to relate my experience. As you did, I carefully selected a new computer case and power supply from the stock at redacted, paying careful attention to the FCC logo on the power supply. After moving the mother board over and turning it on, it completely wiped out reception of the local 5kW station on 550 kHz. Fortunately, I had picked up a couple of surplus Corcom line filters (Model # 10ESK7)at a local hamfest three years earlier (it pays to collect junk). I spliced it into the computer power cord and it cured the problem completely. I don't have any experience with the Radio Shack line filter (Catalog # 15-1111), but it looks like it might do the job for you. 73, Jim, K7JEB |
C. Crane's Twin Ferrite Antenna
Michael Coslo wrote:
W. Watson wrote: Cecil Moore wrote: W. Watson wrote: Cecil Moore wrote: Why do you think that's a radio problem? :-) When I turn the computer off, the radio station noise drops dramatically. It doesn't matter if I use AC or DC. I can detect the large noise change in my car from the garage. That sounds like a computer problem, not a radio problem. What am I missing? Probably nothing. However, I'd be willing to bet that I wouldn't have this problem if I were 100 miles closer to the radio station. Absolutely. If the station signal is relatively stronger than the computer noise, the computer's RFI will not be so much an issue. Right now, they are about the same strength. Moving the computer will probably help a lot. Just out of curiosity, what is the frequency of the station you are trying to recieve? And while we are at it, is the noise on the radio in just one spot, or is it on pretty much the whole band? - 73 de Mike KB3EIA - 810 AM, KGO. Good question about the width of noise. Let me check ... I just took the radio out near the PC, and operated it on battery. With the PC on, and moving in steps of 10KH from 700 to 900: noise almost everywhere execpt at 830, which is about 3 miles from my house and over a hill. With the PC off, some noise everywhere, but 710 (station and somewhat noisyg), 740 (station and somewhat noisy but not bad-- KCBS inSF, CA), 810 (clean), 840 (station and somewhat noisy). In other words things improved quite a bit. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
K7JEB wrote:
On Wed, 30 Nov 2005 13:26:37 GMT, "W. Watson" wrote: W. Watson wrote: I'll continue to experiment, but so far not so good. Comments? I would like to relate my experience. As you did, I carefully selected a new computer case and power supply from the stock at redacted, paying careful attention to the FCC logo on the power supply. After moving the mother board over and turning it on, it completely wiped out reception of the local 5kW station on 550 kHz. Fortunately, I had picked up a couple of surplus Corcom line filters (Model # 10ESK7)at a local hamfest three years earlier (it pays to collect junk). I spliced it into the computer power cord and it cured the problem completely. I don't have any experience with the Radio Shack line filter (Catalog # 15-1111), but it looks like it might do the job for you. 73, Jim, K7JEB The RShk ferrite rectangles didn't help. Interesting about the Corcom filters. I'm going down to a radio shop on Friday, HSC in Sacramento. Maybe I can find something there. I just checked Google with "Corcom line filters Model # 10ESK7" and found some hits. Look like maybe they are $5.00. Interesting finding about the width of the noise on a msg I just posted a few minutes ago. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
On Thu, 01 Dec 2005 00:20:41 GMT, "W. Watson"
wrote: I don't have any experience with the Radio Shack line filter (Catalog # 15-1111), but it looks like it might do the job for you. The RShk ferrite rectangles didn't help. Interesting about the Corcom filters. I'm going down to a radio shop on Friday, HSC in Sacramento. Maybe I can find something there. Take a look at the 15-1111 on www.radioshack.com. It is NOT a clamp-on ferrite choke, but rather a filter like the Corcom. I just thought it might be a bit more accessible. But if you can find a 10-amp Corcom, go for it! (Actually, a 3-amp model should work). Anyway, your problem is definitely solvable, and for relatively little $$$. Jim, K7JEB |
C. Crane's Twin Ferrite Antenna
Computers and computer components are regulated by the FCC.
They MUST NOT cause interferance to licenced radio services. (like the radio stations you are trying to tune in.) Make that clear to the vendor you got the power supply from! KD5RPO W. Watson wrote: Michael Coslo wrote: W. Watson wrote: I bought this antenna on a 30 day trial, and just got it about 12 hours ago. So far I'm not at all impressed. I live about 150 miles from an AM station, at 810, in the SF/SJ Bay Area, which has a marginal signal, but usually listenable. Putting a new PSU in a PC about a month ago increased the noise in AM radios 70-100' from the PC to an almost unacceptable level. I had hoped the antenna would boost the signal enough to knock down the noise. There are times when I can get a good signal from the station, but certainly less frequently than before. Any rf noise put out by the computer ps is going to be picked up by your antenna as well as the radio station you are trying to hear. So a better antenna (if your new one is indeed better) wil just pick up stronger power supply noise. It's moslty a null situation. What you need to do is get that power supply fixed or replaced - 73 de Mike KB3EIA - I think the only solutions to the PSU problem is to buy a much better one. As I mention above, that's probably a losing proposition. I doubt after 6 weeks they would take it back. It might be worth a try though. Note my comment above to someone a few moments ago that this seems to be a household circuit dependent problem. Another PC in the same room works fine until I plug it into the socket that I first noticed the problem. |
C. Crane's Twin Ferrite Antenna
BKR wrote:
Computers and computer components are regulated by the FCC. They MUST NOT cause interferance to licenced radio services. (like the radio stations you are trying to tune in.) Make that clear to the vendor you got the power supply from! Interesting thought but impractical. It could be the installation (e.g., grounding) vs. the supply itself. Event if the PSU itself, proving it would be a chore. |
C. Crane's Twin Ferrite Antenna
"Phil Wheeler" bravely wrote to "All" (01 Dec 05 09:53:08)
--- on the heady topic of " C. Crane's Twin Ferrite Antenna" PW From: Phil Wheeler PW Xref: core-easynews rec.radio.amateur.antenna:220688 PW BKR wrote: Computers and computer components are regulated by the FCC. They MUST NOT cause interferance to licenced radio services. (like the radio stations you are trying to tune in.) Make that clear to the vendor you got the power supply from! PW Interesting thought but impractical. It could be the installation PW (e.g., grounding) vs. the supply itself. Event if the PSU itself, PW proving it would be a chore. Especially since most of the off-shore stuff may have all the right stickers but be complete fakes of the real thing. A*s*i*m*o*v .... We're young, rich, and full of sugar, what do we do? |
C. Crane's Twin Ferrite Antenna
K7JEB wrote:
On Thu, 01 Dec 2005 00:20:41 GMT, "W. Watson" wrote: I don't have any experience with the Radio Shack line filter (Catalog # 15-1111), but it looks like it might do the job for you. The RShk ferrite rectangles didn't help. Interesting about the Corcom filters. I'm going down to a radio shop on Friday, HSC in Sacramento. Maybe I can find something there. Take a look at the 15-1111 on www.radioshack.com. It is NOT a clamp-on ferrite choke, but rather a filter like the Corcom. I just thought it might be a bit more accessible. But if you can find a 10-amp Corcom, go for it! (Actually, a 3-amp model should work). Anyway, your problem is definitely solvable, and for relatively little $$$. Jim, K7JEB Good. Thanks. I'll try RS tomorrow. Sometimes they don't have to stock them. I'll be going by Fry's Electronics tomorrow in Sacramento. They stock one heck of a lot of electronics stuff. I think I'll call down first or try there web site for the corcom. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in arid or desert country? Check your boots well to see if you have a scorpion in them. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
On 1-Dec-2005, Phil Wheeler wrote: Xref: number1.nntp.dca.giganews.com rec.radio.amateur.antenna:253561 BKR wrote: Computers and computer components are regulated by the FCC. They MUST NOT cause interferance to licenced radio services. (like the radio stations you are trying to tune in.) Make that clear to the vendor you got the power supply from! Interesting thought but impractical. It could be the installation (e.g., grounding) vs. the supply itself. Event if the PSU itself, proving it would be a chore. The noise from PC Power Supplies is usually radiated from the power cord and the house wiring. The cause is often that the manufacturers cut cost by leaving out the L and C components of the line filter. Usually you will find the place on the PSU circuit board to mount a bi-filar choke and two or three capacitors. The capacitors are missing and the pads for the choke are jumpered. If you can find an older junk PSU which has the components, just unsolder them from the junk board and install them in your PSU. Sometimes the PSU's in Monitors have the filter components. When I installed the filter in my old Pentium, the switch mode hash on broadcast band stations went down by 30 db. Installing line filters outside the CPU Case had very little effect. -ken- |
C. Crane's Twin Ferrite Antenna
Ken Fowler wrote:
On 1-Dec-2005, Phil Wheeler wrote: Xref: number1.nntp.dca.giganews.com rec.radio.amateur.antenna:253561 BKR wrote: Computers and computer components are regulated by the FCC. They MUST NOT cause interferance to licenced radio services. (like the radio stations you are trying to tune in.) Make that clear to the vendor you got the power supply from! Interesting thought but impractical. It could be the installation (e.g., grounding) vs. the supply itself. Event if the PSU itself, proving it would be a chore. The noise from PC Power Supplies is usually radiated from the power cord and the house wiring. The cause is often that the manufacturers cut cost by leaving out the L and C components of the line filter. Usually you will find the place on the PSU circuit board to mount a bi-filar choke and two or three capacitors. The capacitors are missing and the pads for the choke are jumpered. If you can find an older junk PSU which has the components, just unsolder them from the junk board and install them in your PSU. Sometimes the PSU's in Monitors have the filter components. When I installed the filter in my old Pentium, the switch mode hash on broadcast band stations went down by 30 db. Installing line filters outside the CPU Case had very little effect. -ken- I was in the HSC store in Sacramento and discovered some filters that were inside the AC switch. I decided against them, since I wasn't sure about the amperage. I would think though the chassis builder might include such devices, but haven't checked. Tomorrow I'll order the corcom filter 10ek7 10 amps that someone suggested from a place in San Jose, CA. $5.00. I'll give that a whirl. Looks like I'll have to cut the cord to put it in the line. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in arid or desert country? Check your boots well to see if you have a scorpion in them. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
This is really weird. The noise stopped! There's no question that when I
first noticed this some weeks ago that it was linked to turning the PC on, and would disappear when I turned it off. I haven't changed anything. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in arid or desert country? Check your boots well to see if you have a scorpion in them. -- Survivorman, Discovery (SCI) Channel Web Page: home.earthlink.net/~mtnviews |
C. Crane's Twin Ferrite Antenna
This is really weird. The noise stopped! There's no question that when I first noticed this some weeks ago that it was linked to turning the PC on, and would disappear when I turned it off. I haven't changed anything. Evil spirits on vacation ......??????? I presently have a severe noise problem on HF ...... every year at this time ....... Chi-Com Christmas displays ?????? I hope your noise stays away for good .. Merry Christmas all ..... 73 Tom KI3R Belle Vernon PA |
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