How can I eliminate TV interference on shortwave?
 

When my neighbors turn their TVs on, I have to turn off my shortwave
radio because I get a terrible buzzing interference over most of the
shortwave band. I can't hear a thing. I also get a similar problem
when my wife turns on a florescent light in the kitchen. Is there
anyway to reduce or eliminate this kind of interference?

Rob KC7BUM
Portland, Oregon

On 14 Oct 2003 21:18:24 -0700, (Robert Williams)
wrote:

When my neighbors turn their TVs on, I have to turn off my shortwave
radio because I get a terrible buzzing interference over most of the
shortwave band. I can't hear a thing. I also get a similar problem
when my wife turns on a florescent light in the kitchen. Is there
anyway to reduce or eliminate this kind of interference?

Rob KC7BUM
Portland, Oregon

Hi Rob,

There's one of two possibilities, and possibly both.

1. You need to make your antenna remote from living spaces and
connect to it with a choked coaxial transmission line. Choking can be
accomplished using 1:1 BalUns or simply winding 6 to 8 loops of line
in 6 to 8 inch loops near the antenna connection. This will aid in
over-the-air interference if that is the problem (TVs and lights don't
usually bother one beyond 20-40 feet).

2. You need to isolate your radio's power source from power lines
that have noise arriving from these TVs or lights. Sometimes this can
be accomplished by merely plugging into a different AC outlet, or a
different one in a different room. The plan here is to move away from
a breaker that has noisy electronics on it. This will aid in
conduction noise reduction which seems to be more likely, but odd that
neighbors are involved (unless you are in an apartment situation). An
even simpler test is to disconnect all ground connections (this comes
in through the outlet in one form or another) and running off battery
power. This means that the antenna connection has to be free of a
ground connection too (and no wall-warts charging your batteries while
trying this either, nor having your audio-out plugged into your home
entertainment system or hi-fi). This is a shared ground problem if it
is indeed the source of noise.

73's
Richard Clark, KB7QHC

Robert,

If you ever buy a new SW radio, make sure it has a noise blanker. It won't
completely eliminate the noise, but pulse type noise can easily be reduced
by 20 db or more.

You should be able to fix the florescent light problem. First, I would
replace the starter. On the TVs, get the neighbors to put ferrite beads on
the TV power cords. If they use outdoor antennas, they might need those on
the antenna leadins also.

And, of course, as Richard told you, get the antenna as far removed from all
noise as you can.

Tam/WB2TT
"Robert Williams" wrote in message
om...
When my neighbors turn their TVs on, I have to turn off my shortwave
radio because I get a terrible buzzing interference over most of the
shortwave band. I can't hear a thing. I also get a similar problem
when my wife turns on a florescent light in the kitchen. Is there
anyway to reduce or eliminate this kind of interference?

Rob KC7BUM
Portland, Oregon

What make and model?

As for your next door TV. It is either old and the flyback is arcing, newer
and the tripler is cracked and arcing or they have big bucks and it's
PLASMA. There should be no other reason to be getting noise from a TV next
door.

Some one already suggested the 1st thing I would do with the lighting is to
change out the starter. If you SW Radio has batteries, try it on batteries.
If the noise is still there from the lights, it is the starter. If you are
using AC, try a circuit not shared by the lighting.

If it does use batteries, take it for a walk and see where the noise is the
worse and work from there.

JD


"Robert Williams" wrote in message
om...
When my neighbors turn their TVs on, I have to turn off my shortwave
radio because I get a terrible buzzing interference over most of the
shortwave band. I can't hear a thing. I also get a similar problem
when my wife turns on a florescent light in the kitchen. Is there
anyway to reduce or eliminate this kind of interference?

Rob KC7BUM
Portland, Oregon

Robert Williams wrote:

When my neighbors turn their TVs on, I have to turn off my shortwave
radio because I get a terrible buzzing interference over most of the
shortwave band. I can't hear a thing. I also get a similar problem
when my wife turns on a florescent light in the kitchen. Is there
anyway to reduce or eliminate this kind of interference?

Rob KC7BUM
Portland, Oregon

Simple things first. If your receiver doesn't have a polarized ac plug,
try turning it around -- sometimes that can make a difference. especially
if it is coming through the ac lines.

Hope this helps -- its quick and simple.

Irv VE6BP
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