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#1
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While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB
mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug |
#2
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![]() "DougSlug" wrote in message ... While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug The horizontal sweep of television sets is 15750 Hz. Switch mode power supplies operate anywhere from 10 kHz to 100 kHz. It is not uncommon for either of them to ring and generate harmonics in HF. -- rb |
#3
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On Mar 8, 3:03 am, "Ron Baker, Pluralitas!"
wrote: "DougSlug" wrote in message ... While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug The horizontal sweep of television sets is 15750 Hz. Switch mode power supplies operate anywhere from 10 kHz to 100 kHz. It is not uncommon for either of them to ring and generate harmonics in HF. -- rb least you know the rx's working :-) |
#4
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![]() "Edmund H. Ramm" wrote in message ... In "Ron Baker, Pluralitas!" writes: "DougSlug" wrote in message ... While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug The horizontal sweep of television sets is 15750 Hz. Switch mode power supplies operate anywhere from 10 kHz to 100 kHz. It is not uncommon for either of them to ring and generate harmonics in HF. In the case of switch mode power supplies the spikes IMO would be 120Hz apart (100Hz where I live). And most of the rf energy is spilled from abt. 1 to 7 MHz, with almost nothing left to be found on 28MHz. 73, Eddi ._._. -- e-mail: dk3uz AT darc DOT de | AMPRNET: If replying to a Usenet article, please use above e-mail address. Linux/m68k, the best U**x ever to hit an Atari! The mains frequency has little to do with the noise that a switcher can generate. A switcher rectifies and filters the mains to DC then uses a switching transistor to drive a transformer at a much higher frequency. Tens of kHz typically. The higher frequency allows the "magnetics", i.e. the tranformer, to be much smaller physically than a 60 (50) Hz transformer. That plus the on-off and not linear nature of the switch allows switching power supplies to be smaller and more efficient than linear supplies. It is the switching, with sharp edges, that generates high frequency components. I've seen poorly designed switchers generate harmonics into the hundreds of MHz. -- rb |
#5
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"Ron Baker, Pluralitas!" wrote in message
... "Edmund H. Ramm" wrote in message ... In "Ron Baker, Pluralitas!" writes: "DougSlug" wrote in message ... While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug The horizontal sweep of television sets is 15750 Hz. Switch mode power supplies operate anywhere from 10 kHz to 100 kHz. It is not uncommon for either of them to ring and generate harmonics in HF. In the case of switch mode power supplies the spikes IMO would be 120Hz apart (100Hz where I live). And most of the rf energy is spilled from abt. 1 to 7 MHz, with almost nothing left to be found on 28MHz. 73, Eddi ._._. -- e-mail: dk3uz AT darc DOT de | AMPRNET: If replying to a Usenet article, please use above e-mail address. Linux/m68k, the best U**x ever to hit an Atari! The mains frequency has little to do with the noise that a switcher can generate. A switcher rectifies and filters the mains to DC then uses a switching transistor to drive a transformer at a much higher frequency. Tens of kHz typically. The higher frequency allows the "magnetics", i.e. the tranformer, to be much smaller physically than a 60 (50) Hz transformer. That plus the on-off and not linear nature of the switch allows switching power supplies to be smaller and more efficient than linear supplies. It is the switching, with sharp edges, that generates high frequency components. I've seen poorly designed switchers generate harmonics into the hundreds of MHz. -- rb I understand about the noise and harmonics a switcher can generate, but the thing is that my antenna is mounted outside on a mast 25 feet up. All the wiring in my neighborhood is underground. It's not clear to me how I could be getting such strong interference in this case. What about harmonics from wireless routers? Could that explain this interference pattern? - Doug |
#6
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![]() "DougSlug" wrote in message ... "Ron Baker, Pluralitas!" wrote in message ... "Edmund H. Ramm" wrote in message ... In "Ron Baker, Pluralitas!" writes: "DougSlug" wrote in message ... While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug The horizontal sweep of television sets is 15750 Hz. Switch mode power supplies operate anywhere from 10 kHz to 100 kHz. It is not uncommon for either of them to ring and generate harmonics in HF. In the case of switch mode power supplies the spikes IMO would be 120Hz apart (100Hz where I live). And most of the rf energy is spilled from abt. 1 to 7 MHz, with almost nothing left to be found on 28MHz. 73, Eddi ._._. -- e-mail: dk3uz AT darc DOT de | AMPRNET: If replying to a Usenet article, please use above e-mail address. Linux/m68k, the best U**x ever to hit an Atari! The mains frequency has little to do with the noise that a switcher can generate. A switcher rectifies and filters the mains to DC then uses a switching transistor to drive a transformer at a much higher frequency. Tens of kHz typically. The higher frequency allows the "magnetics", i.e. the tranformer, to be much smaller physically than a 60 (50) Hz transformer. That plus the on-off and not linear nature of the switch allows switching power supplies to be smaller and more efficient than linear supplies. It is the switching, with sharp edges, that generates high frequency components. I've seen poorly designed switchers generate harmonics into the hundreds of MHz. -- rb I understand about the noise and harmonics a switcher can generate, but the thing is that my antenna is mounted outside on a mast 25 feet up. All the wiring in my neighborhood is underground. It's not clear to me how I could be getting such strong interference in this case. What about harmonics from wireless routers? Could that explain this interference pattern? - Doug It seems very unlikely to me. That stuff is up in the GHz. They don't tend to make subharmonics. My computer monitor has a 62 kHz horizontal sweep. There are various places on HF that I pick up "carriers" evenly spaced at 62 kHz. (Antenna is outside, connected with coax.) When I switch off the monitor the "carriers" disappear. One thing to try is to remove power from everything in the house. You can't just turn them off, you have to disconnect the power. I have a Sony stereo that makes RF noise if it is just plugged in. You can switch off all the circuit breakers to everything but the radio. (And unplug anything left on the live circuit.) Or if you can power the radio with batteries then switch off all or the main breaker. See how much noise goes away then. -- rb |
#7
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What about harmonics from wireless routers? Could that explain this
interference pattern? - Doug It seems very unlikely to me. That stuff is up in the GHz. They don't tend to make subharmonics. The carrier frequency is around 2.4 GHz, sure, but the data bursts are quite a bit slower. What I don't know about is whether wireless routers broadcast data bursts at regular intervals that somehow may be getting demodulated in my receiver. My computer monitor has a 62 kHz horizontal sweep. There are various places on HF that I pick up "carriers" evenly spaced at 62 kHz. (Antenna is outside, connected with coax.) When I switch off the monitor the "carriers" disappear. I use an LCD panel. Turning that off makes no difference, as expected. One thing to try is to remove power from everything in the house. You can't just turn them off, you have to disconnect the power. I have a Sony stereo that makes RF noise if it is just plugged in. You can switch off all the circuit breakers to everything but the radio. (And unplug anything left on the live circuit.) Or if you can power the radio with batteries then switch off all or the main breaker. See how much noise goes away then. I've gone through this process when chasing down a nasty buzz in the AM and SW broadcast bands. I found that the light dimmers on my outdoor spotlights caused a nasty buzz all across the bands, not at any kind of regularly spaced frequencies. That sound was also quite different than what I am getting now. I'll have to explore that idea some more. Thanks, and keep the ideas coming...hopefully we'll figure it out. - Doug |
#8
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![]() ----- Original Message ----- From: "DougSlug" Newsgroups: rec.radio.scanner,alt.radio.scanner,alt.ham-radio.hf Sent: Saturday, March 10, 2007 7:08 PM Subject: Carrier tones every 15 kHz in 10m band What about harmonics from wireless routers? Could that explain this interference pattern? - Doug It seems very unlikely to me. That stuff is up in the GHz. They don't tend to make subharmonics. The carrier frequency is around 2.4 GHz, sure, but the data bursts are quite a bit slower. What I don't know about is whether wireless routers broadcast data bursts at regular intervals that somehow may be getting demodulated in my receiver. It is the wireless router, a NetGear WGR614. I don't know why the hell I didn't try that earlier. It does the exact same thing to my Icom IC-R20. Maybe the power supply in the router? Or is it a wireless signal phenomenon? - Doug |
#9
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wireless router what at 2.4ghz!!
try killing the power to your house while running the RX'er from a battery or car. that should give you agood idea if its you or not mike "DougSlug" wrote in message ... "Ron Baker, Pluralitas!" wrote in message ... "Edmund H. Ramm" wrote in message ... In "Ron Baker, Pluralitas!" writes: "DougSlug" wrote in message ... While tuning through the 28.3 to 28.5 MHz portion of the 10m band in USB mode, I get what sound like carrier tones very evenly spaced every 15 kHz starting at about 28.3 MHz. I am using an AOR AR8600MkII receiver with an AOR SA7000 antenna mounted on a mast outside. I am located in central NJ in the Princeton/Trenton area. What is the source of these tones? Thanks, Doug The horizontal sweep of television sets is 15750 Hz. Switch mode power supplies operate anywhere from 10 kHz to 100 kHz. It is not uncommon for either of them to ring and generate harmonics in HF. In the case of switch mode power supplies the spikes IMO would be 120Hz apart (100Hz where I live). And most of the rf energy is spilled from abt. 1 to 7 MHz, with almost nothing left to be found on 28MHz. 73, Eddi ._._. -- e-mail: dk3uz AT darc DOT de | AMPRNET: If replying to a Usenet article, please use above e-mail address. Linux/m68k, the best U**x ever to hit an Atari! The mains frequency has little to do with the noise that a switcher can generate. A switcher rectifies and filters the mains to DC then uses a switching transistor to drive a transformer at a much higher frequency. Tens of kHz typically. The higher frequency allows the "magnetics", i.e. the tranformer, to be much smaller physically than a 60 (50) Hz transformer. That plus the on-off and not linear nature of the switch allows switching power supplies to be smaller and more efficient than linear supplies. It is the switching, with sharp edges, that generates high frequency components. I've seen poorly designed switchers generate harmonics into the hundreds of MHz. -- rb I understand about the noise and harmonics a switcher can generate, but the thing is that my antenna is mounted outside on a mast 25 feet up. All the wiring in my neighborhood is underground. It's not clear to me how I could be getting such strong interference in this case. What about harmonics from wireless routers? Could that explain this interference pattern? - Doug |
#10
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weird!!!!!
psu then or xlal osc inside for baud rate etc. try it on a battery mike "DougSlug" wrote in message ... ----- Original Message ----- From: "DougSlug" Newsgroups: rec.radio.scanner,alt.radio.scanner,alt.ham-radio.hf Sent: Saturday, March 10, 2007 7:08 PM Subject: Carrier tones every 15 kHz in 10m band What about harmonics from wireless routers? Could that explain this interference pattern? - Doug It seems very unlikely to me. That stuff is up in the GHz. They don't tend to make subharmonics. The carrier frequency is around 2.4 GHz, sure, but the data bursts are quite a bit slower. What I don't know about is whether wireless routers broadcast data bursts at regular intervals that somehow may be getting demodulated in my receiver. It is the wireless router, a NetGear WGR614. I don't know why the hell I didn't try that earlier. It does the exact same thing to my Icom IC-R20. Maybe the power supply in the router? Or is it a wireless signal phenomenon? - Doug |
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