It is back interference from the modern switching power supplies. We used to
use Transformers to render different voltages for the radio/television etc.,
but since the early 90s, we use fancy transistors to chop up the line
voltage into little time segments to get lower voltage. The noise we get is
from those transistors which generate incredible peaks, valleys, and
harmonics. Some of the signal comes back down the plug and wire and some of
it is radiated. So it's always a challenge to damp it out. There a good
thing, however, or wall warts and laptop power cables would have to be a lot
bigger and heavier.
There are things called line chokes which are comprised of a ferrous metal
hoop through which you can wind a line cord and it will help to dampen down
interference coming back up the power cable. They're not very expensive.
Geoff
-----Original Message-----
From: Steve Jacobson
Sent: Saturday, August 01, 2020 1:04 PM
To: all-audio@groups.io
Subject: Re: [all-audio] Maybe for this group or if not...where
Tom,
Agreed completely. I had a sudden increase perhaps a month ago in the
interference I am getting on the AM band from my DSL service. The phone
company must have changed something either with the phone lines outside or
with the DSL settings. While I know there is always DSl interference along
the wires carrying the DSL signal, it is also getting radiated from the AC
lines as well. I can't figure out how it is getting into those circuits.
I have a tuner with one of those little square loops and I made a larger
loop on a piece of cardboard and added a length of cable so I could move it
around more. That really helped me escape some interference until this new
DSL problem started. I still like to look for long distance AM reception
especially during the winter evenings, and this interference really
decreases my ability to do that.
Best regards,
Steve Jacobson
-----Original Message-----
From: all-audio@groups.io <all-audio@groups.io> On Behalf Of Tom Kaufman
Sent: Saturday, August 1, 2020 11:36 AM
To: all-audio@groups.io
Subject: Re: [all-audio] Maybe for this group or if not...where
Steve and list: It's amazing to think of just how many things we have
around the house that generate noise; things that we "have" to have to help
us function, such as our phones (cordless or otherwise) chargers,
modems...etc.! My cable modem really reeks habic with my AM radio; my
stereo system is back here; so is my modem! So there's not a lot I can do
about that! Problem is that this modem definitely does create noise on the
AM band! So since I can't pick up and move my stereo, there's just not a
lot I can do about it! I can position that little antenna that is hooked
into my stereo and hold it there with my hand, thus, it does help with the
noise! Problem is, as soon as I remove my hand, then it goes right back to
the position where it picks up the noise, so there's just no real "getting
away from it!"
Tom Kaufman
-----Original Message-----
From: all-audio@groups.io [mailto:all-audio@groups.io] On Behalf Of Steve
Jacobson
Sent: Saturday, August 01, 2020 12:18 PM
To: all-audio@groups.io
Subject: Re: [all-audio] Maybe for this group or if not...where
Georgina,
If I take my cordless phone and put it near an AM radio, I find that it
generates a good bit of digital noise across the entire AM band, but there
are oscillations that occur here and there that are stronger than the
general noise. I would guess that on his system, one of those stronger
oscillations happens to hit WBBM. Unfortunately, it is all a bunch of
guesswork on my part and there is a lot we don't know about his system. I
might be totally wrong. I am struggling with a problem with noise and
interference on the AM band in my house which is very hard to track down, so
there might be something more to this problem as well.
Best regards,
Steve Jacobson
-----Original Message-----
From: all-audio@groups.io <all-audio@groups.io> On Behalf Of Georgina Joyce
Sent: Friday, July 31, 2020 12:08 PM
To: all-audio@groups.io
Subject: Re: [all-audio] Maybe for this group or if not...where
Hello Steve,
URRRRR, shows you how long since I listened and took note of the AM band.
Whoops. At least someone is there to put me right. Found it interesting that
other radio stations perhaps not on AM did not suffer in the same way.
Regards,
On 31 Jul 2020, at 16:55, Steve Jacobson <steve.jacob...@outlook.com>
wrote:
Since the radio station is 780 KHZ, it is likely that the interference is
not caused by the frequency used by the phone, but that it is getting
interference from the digital circuits in the phone. Usually this happens
if your radio is close to the answering system or that you have placed the
wireless headphones near your radio. If neither is the case, check to see
if the cords running to the answer machine might be passing close to your
radio. Gina is right that an external antenna probably would correct this,
but moving the answering machine or making sure your headphones are not near
the radio should help. If you keep your headphones in a charger when they
are not being used, check to be sure the cord to the charger does not run
close to the radio. Making sure the radio is plugged into a different
outlet from the answering machine or any headphone chargers might be worth
trying as well. If your radio has a separate square loop antenna, moving
that around can make a big difference as well.
I live in Minnesota but listen to WBBM occasionally, and I have heard them
announce that they are also on FM on 105.9. You might be able to avoid this
by trying the FM frequency instead. I do not know if the coverage of the FM
frequency reaches you, though, but it might be worth checking.
Best regards,
Steve Jacobson
On 31 Jul 2020, at 03:47, Morey Worthington <worthing...@wi.rr.com
<mailto:worthing...@wi.rr.com>> wrote:
Evening all.
This is a audio related question, but has to do with a certain radio
station and a wireless cell phone.
I live North of Chicago Il. and listen to a ceertain powerful all news
station on AM (WBBM 780). We have a phone answering system with 3 wireless
headsets.
If If I am listening to the Chicago station and the phone starts ringing,
usually for the wife, a loud whisteling noise happens and stays there till
the call is finished. This only happens on this one station . I have tried
unplugging radio, the phone system, but no change. If I change the radio
station to another, all is well. I have tried moving the direction of radio,
it is a digital one, with nothing any different.
I am really sorry to ask this group about my issue, but it is audio
related. If not for this group, can someone , maybe, give me direction on
where to turn??
Thanks,
Morey Worthington
Georgina
Call: M0EBP
DMR ID: 2346259
Allstar: 52178
Locater: IO83PS
Georgina
Call: M0EBP
DMR ID: 2346259
Allstar: 52178
Locater: IO83PS
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