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#11
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Dave,
Thanks for the info. In my case, the source seems to be a bank of 4 transformers on a pole about 300 feet away. Weirdest thing I had was S9 white noise from about 40 to 55 MHz with about 50% amplitude modulation at around 50 KHz. Turned out to be a 60 amp cartridge fuse in my fuse box about to go bad. I think the 50 KHz was a mechanical resonance in the fuse. I don't know about the 746, but my 756 has dual watch capability, which lets you listen to two frequencies at the same time. It would be interesting if they would let you vary the phase of the secondary channel.. Tam/WB2TT "Dave Shrader" wrote in message et... My ANC-4 is sitting on top of the ICOM 746. I have a short piece of coax, 7 to 8 feet, to a doublet with a total length of 8 feet on the floor against an outside wall. Works Great! I've used the ANC-4 for almost two years. While in Massachusetts the QTH was 100 meters from the New England Power Grid with three sets of high tension [ 67,000 volts] three phase power lines [nine wires total]. The power lines were generally quite quiet but during summer humidity and/or thunderstorms they would get 'noisy'. The ANC-4 reduced the noise to S1 typical levels. Here in New Hampshire, my local noise source is the local LAN where the router is four feet from my receiver. Similar results with the ANC-4. BTW, it was given to me as a gift by W1KSZ who picked it up on e-bay for about $60.00. Thanks many times over, Dick. DD, W1MCE |
#12
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Dave,
Thanks for the info. In my case, the source seems to be a bank of 4 transformers on a pole about 300 feet away. Weirdest thing I had was S9 white noise from about 40 to 55 MHz with about 50% amplitude modulation at around 50 KHz. Turned out to be a 60 amp cartridge fuse in my fuse box about to go bad. I think the 50 KHz was a mechanical resonance in the fuse. I don't know about the 746, but my 756 has dual watch capability, which lets you listen to two frequencies at the same time. It would be interesting if they would let you vary the phase of the secondary channel.. Tam/WB2TT "Dave Shrader" wrote in message et... My ANC-4 is sitting on top of the ICOM 746. I have a short piece of coax, 7 to 8 feet, to a doublet with a total length of 8 feet on the floor against an outside wall. Works Great! I've used the ANC-4 for almost two years. While in Massachusetts the QTH was 100 meters from the New England Power Grid with three sets of high tension [ 67,000 volts] three phase power lines [nine wires total]. The power lines were generally quite quiet but during summer humidity and/or thunderstorms they would get 'noisy'. The ANC-4 reduced the noise to S1 typical levels. Here in New Hampshire, my local noise source is the local LAN where the router is four feet from my receiver. Similar results with the ANC-4. BTW, it was given to me as a gift by W1KSZ who picked it up on e-bay for about $60.00. Thanks many times over, Dick. DD, W1MCE |
#13
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Tarmo Tammaru wrote:
Dave, Thanks for the info. In my case, the source seems to be a bank of 4 transformers on a pole about 300 feet away. Weirdest thing I had was S9 white noise from about 40 to 55 MHz with about 50% amplitude modulation at around 50 KHz. Turned out to be a 60 amp cartridge fuse in my fuse box about to go bad. I think the 50 KHz was a mechanical resonance in the fuse. ... There are lots of weird noise sources. As a kid in the 40s, I was part of a family visit to an old farm west of Bethlehem Pa., in what was definitely "fringe area" TV reception. The man of the house was telling my father about the strong zig-zag pattern that sometimes showed up on the screen, blanking out the video and often lousing up vertical synch. He wanted to know if the FCC would track down the interference; he thought it was a ham about half a mile away. Just then, the interference started, and right after, his son came downstairs to join us. A little while later, his daughter went upstairs, and the interference cleared when she got to the top. Without saying anything, I went over to the stairway switch and turned it on and off a few times. "On" caused the interference. When we swapped the bulb with one in a floor lamp, the floor lamp caused the same interference. It has been one of my enduring regrets that I didn't ask to keep the bulb. It was probably thrown out. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ |
#14
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Tarmo Tammaru wrote:
Dave, Thanks for the info. In my case, the source seems to be a bank of 4 transformers on a pole about 300 feet away. Weirdest thing I had was S9 white noise from about 40 to 55 MHz with about 50% amplitude modulation at around 50 KHz. Turned out to be a 60 amp cartridge fuse in my fuse box about to go bad. I think the 50 KHz was a mechanical resonance in the fuse. ... There are lots of weird noise sources. As a kid in the 40s, I was part of a family visit to an old farm west of Bethlehem Pa., in what was definitely "fringe area" TV reception. The man of the house was telling my father about the strong zig-zag pattern that sometimes showed up on the screen, blanking out the video and often lousing up vertical synch. He wanted to know if the FCC would track down the interference; he thought it was a ham about half a mile away. Just then, the interference started, and right after, his son came downstairs to join us. A little while later, his daughter went upstairs, and the interference cleared when she got to the top. Without saying anything, I went over to the stairway switch and turned it on and off a few times. "On" caused the interference. When we swapped the bulb with one in a floor lamp, the floor lamp caused the same interference. It has been one of my enduring regrets that I didn't ask to keep the bulb. It was probably thrown out. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ |
#15
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Tam- never had much luck with one got (also 6 meter op), but , also, BEWARE
if into weak signal stuff - has 6 dB LOSS on recieve (DC bands, who cared, background noise worse than that, but at VHF ???) If you want one, make you good deal! Jim NN7K Tam wrote: Randy, Thanks for your response. The obvious thing you would like to do is to have the software be smart enough to distinguish between signal and noise. But then the hardware becomes moot, and you have invented a better DSP noise reduction circuit. BTW, I am considering getting an ANC4 to get rid of power line noise on 6 meters. Fortunately, the noise is coming from the North, a very seldom used beam heading. Tam/WB2TT |
#16
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Tam- never had much luck with one got (also 6 meter op), but , also, BEWARE
if into weak signal stuff - has 6 dB LOSS on recieve (DC bands, who cared, background noise worse than that, but at VHF ???) If you want one, make you good deal! Jim NN7K Tam wrote: Randy, Thanks for your response. The obvious thing you would like to do is to have the software be smart enough to distinguish between signal and noise. But then the hardware becomes moot, and you have invented a better DSP noise reduction circuit. BTW, I am considering getting an ANC4 to get rid of power line noise on 6 meters. Fortunately, the noise is coming from the North, a very seldom used beam heading. Tam/WB2TT |
#17
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On Fri, 08 Aug 2003 13:31:25 -0400, Jerry Avins wrote:
Tarmo Tammaru wrote: Dave, Thanks for the info. In my case, the source seems to be a bank of 4 transformers on a pole about 300 feet away. Weirdest thing I had was S9 white noise from about 40 to 55 MHz with about 50% amplitude modulation at around 50 KHz. Turned out to be a 60 amp cartridge fuse in my fuse box about to go bad. I think the 50 KHz was a mechanical resonance in the fuse. ... There are lots of weird noise sources. As a kid in the 40s, I was part of a family visit to an old farm west of Bethlehem Pa., in what was definitely "fringe area" TV reception. The man of the house was telling my father about the strong zig-zag pattern that sometimes showed up on the screen, blanking out the video and often lousing up vertical synch. He wanted to know if the FCC would track down the interference; he thought it was a ham about half a mile away. Just then, the interference started, and right after, his son came downstairs to join us. A little while later, his daughter went upstairs, and the interference cleared when she got to the top. Without saying anything, I went over to the stairway switch and turned it on and off a few times. "On" caused the interference. When we swapped the bulb with one in a floor lamp, the floor lamp caused the same interference. It has been one of my enduring regrets that I didn't ask to keep the bulb. It was probably thrown out. Jerry I think that one may have been intended for an embassy somewhere... Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org |
#18
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On Fri, 08 Aug 2003 13:31:25 -0400, Jerry Avins wrote:
Tarmo Tammaru wrote: Dave, Thanks for the info. In my case, the source seems to be a bank of 4 transformers on a pole about 300 feet away. Weirdest thing I had was S9 white noise from about 40 to 55 MHz with about 50% amplitude modulation at around 50 KHz. Turned out to be a 60 amp cartridge fuse in my fuse box about to go bad. I think the 50 KHz was a mechanical resonance in the fuse. ... There are lots of weird noise sources. As a kid in the 40s, I was part of a family visit to an old farm west of Bethlehem Pa., in what was definitely "fringe area" TV reception. The man of the house was telling my father about the strong zig-zag pattern that sometimes showed up on the screen, blanking out the video and often lousing up vertical synch. He wanted to know if the FCC would track down the interference; he thought it was a ham about half a mile away. Just then, the interference started, and right after, his son came downstairs to join us. A little while later, his daughter went upstairs, and the interference cleared when she got to the top. Without saying anything, I went over to the stairway switch and turned it on and off a few times. "On" caused the interference. When we swapped the bulb with one in a floor lamp, the floor lamp caused the same interference. It has been one of my enduring regrets that I didn't ask to keep the bulb. It was probably thrown out. Jerry I think that one may have been intended for an embassy somewhere... Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org |
#19
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![]() Without saying anything, I went over to the stairway switch and turned it on and off a few times. "On" caused the interference. When we swapped the bulb with one in a floor lamp, the floor lamp caused the same interference. It has been one of my enduring regrets that I didn't ask to keep the bulb. It was probably thrown out. ================ That bulb was probably an old coiled 'Edison' type . They were /are known to form a tuned circuit resonating in the old TV band 1 ( about 48 - 62 MHz) acting as a TX when power is applied. Frank GM0CSZ / KN6WH |
#20
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![]() Without saying anything, I went over to the stairway switch and turned it on and off a few times. "On" caused the interference. When we swapped the bulb with one in a floor lamp, the floor lamp caused the same interference. It has been one of my enduring regrets that I didn't ask to keep the bulb. It was probably thrown out. ================ That bulb was probably an old coiled 'Edison' type . They were /are known to form a tuned circuit resonating in the old TV band 1 ( about 48 - 62 MHz) acting as a TX when power is applied. Frank GM0CSZ / KN6WH |
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Automatic RF noise cancellation and audio noise measurement | Antenna |