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

"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

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 :-)

"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

"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

"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

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

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

Folks, be awared of that flatscreens (PLASMA) is a highly annoying
"jammer" noicetransmitter on the whole HF-band.
As that is NOT for the LCD.



mikeFNB wrote:
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

Someone in my neighbourhood got a new toy for Christmas, and when they play
with it I get a noise repeating precisely every 200 kHz from about 4 MHz
though to 30 MHz - some places worse than others - i.e. around 8 and 15 MHz
they exceed S9. I have sent audio and spectrum recordings to a specialist in
RFI, who was able to determine that it is a switcing power supply, but just
which one and for what is still unknown.

All wiring in my subdivision, including telephone and cable TV is
underground. Other than satellite TV antennas the only visible antennas or
feedlines within at least half a mile are mine. When spring comes I'll try
to localise it with a portable receiver. It is definitely none of my
immediate, within 200 feet, neighbours. I suspect a plasma TV.

In the meantime I just have to avoid multiples of 200 kHz when whatever it
is is being used.

Dave

"Edmund H. Ramm" wrote in message
...
In "DougSlug"
writes:

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.

The neighbours' tv aerials are also underground? The neighbours'
inhouse mains wiring is underground?

It's not clear to me how I could be getting such strong interference
in this case.

The rf energy creeps up the coax' braid and along the mains wiring and
is radiated from there.

My neighbour once had a switch mode psu which pegged my rx' s-meter
on 80m and was still about S5 1km away (spikes 100Hz apart).

QRM from el cheapo switching psus can possibly be cured on a one by
one basis, as hopefully there aren't too many of them. As all and sundry
have at least one tv set at home, QRM from the line output stages has to
be endured or somehow be reduced at the receiving end (notch filter et
al).
If it's any consolation to you, the latter type of QRM will gradually fade
away as more and more flat-screen tv sets enter homes, and will be
replaced
by a much more horrible QRM when said flat-screen is of the plasma
variety.

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!