Inline Isolators for RFI reduction ?
 

On 1/16/2011 5:07 PM, bpnjensen wrote:

...
Short answer - I am getting desperate over the noise level here.
Grasping at straws.

The fellow I spoke to who makes these things said they are best used
as close to the receiver input as possible.

You will certainly need to locate the noise source and place the antenna
as far away as possible and orientate the antenna so the direction
favored by the particular antenna is pointed AWAY form the noise source.
You will probably want to use a 9:1 balun and use coax for the run
past any noise source and to provide isolation from noise sources in the
home. A GOOD GROUND on the receiver will serve you well. If possible,
would also be good to ground the coax braid at the antenna, or run a
wire down to ground as short as possible ...

Regards,
JS

Inline Isolators for RFI reduction ?
 

On Jan 16, 5:17*pm, John Smith wrote:
On 1/16/2011 5:08 PM, bpnjensen wrote:

...
Thanks, Dave, but I am afraid I don't even know what these devices are
or how they'd be used.

This might help:http://www.iw5edi.com/ham-radio/?how...-traps-work,88

Regards,
JS

Sorry - I know what a trap is - but the thingies Dave linked to do not
look like anything in my experience.

Inline Isolators for RFI reduction ?
 

On Jan 16, 5:45*pm, dave wrote:
On 01/16/2011 05:07 PM, bpnjensen wrote:









On Jan 16, 1:34 pm, *wrote:
On Jan 16, 11:24 am, *wrote:

Question to those who may have used one - Do inline isolators work
well on RX? *Such as those sold by Radioworks?

Thanks,
Bruce Jensen

BpnJ : Why are you considering an Inline Isolator ?

1st and "Inline Isolator" requires inserting something
'in-the-line' in the Antenna to Radio Feed-in-Line.

2nd the "Inline Isolator" requires two more Connections
{Joints} in the Antenna to Radio Feed-in-Line.

*If* Your Antenna to Radio Feed-in-Line is less that
150 Feet : Then most likely you do not need an
"Inline Isolator".

*If* Your Antenna to Radio Feed-in-Line is on-the-ground
or buried-under-the-ground a few inches : Then most
likely you do not need an "Inline Isolator".

However : If your Antenna to Radio Feed-in-Line is
In-the-Air {Overhead} from Tree to House : Then may
be you could use and *"Inline Isolator" at the House
entry-point with another Grounding Point/Ground Rod.

The "Correct Way" to Install a Longwire Antenna and Balun
by Wellbrook =http://www.wellbrook.uk.com/longwire.html
We have all most likely done it the wrong way more than once . . .http://groups.google.com/group/rec.r...5cc467b35a70d5
* .
* .

Short answer - I am getting desperate over the noise level here.
Grasping at straws.

The fellow I spoke to who makes these things said they are best used
as close to the receiver input as possible.

You gotta build a loop.

Maybe so. Know of any good plans for something that will fit on a
pinhead?

Inline Isolators for RFI reduction ?
 

On Jan 16, 6:09*pm, John Smith wrote:
On 1/16/2011 5:07 PM, bpnjensen wrote:

...
Short answer - I am getting desperate over the noise level here.
Grasping at straws.

The fellow I spoke to who makes these things said they are best used
as close to the receiver input as possible.

You will certainly need to locate the noise source and place the antenna
as far away as possible and orientate the antenna so the direction
favored by the particular antenna is pointed AWAY form the noise source.
* You will probably want to use a 9:1 balun and use coax for the run
past any noise source and to provide isolation from noise sources in the
home. *A GOOD GROUND on the receiver will serve you well. *If possible,
would also be good to ground the coax braid at the antenna, or run a
wire down to ground as short as possible ...

Regards,
JS

John, thanks - but my whole neighborhood is a noise source. That's no
joke. Otherwise, I know all of this already, and have already built
it to the best possible configuration, much as you've described here.

Inline Isolators for RFI reduction ?
 

On Jan 16, 5:14*pm, bpnjensen wrote:
On Jan 16, 1:34*pm, RHF wrote:



On Jan 16, 11:24*am, bpnjensen wrote:

Question to those who may have used one - Do inline isolators work
well on RX? *Such as those sold by Radioworks?

Thanks,
Bruce Jensen

BpnJ : Why are you considering an Inline Isolator ?

1st and "Inline Isolator" requires inserting something
'in-the-line' in the Antenna to Radio Feed-in-Line.

2nd the "Inline Isolator" requires two more Connections
{Joints} in the Antenna to Radio Feed-in-Line.

*If* Your Antenna to Radio Feed-in-Line is less that
150 Feet : Then most likely you do not need an
"Inline Isolator".

*If* Your Antenna to Radio Feed-in-Line is on-the-ground
or buried-under-the-ground a few inches : Then most
likely you do not need an "Inline Isolator".

However : If your Antenna to Radio Feed-in-Line is
In-the-Air {Overhead} from Tree to House : Then may
be you could use and *"Inline Isolator" at the House
entry-point with another Grounding Point/Ground Rod.

The "Correct Way" to Install a Longwire Antenna and Balun
by Wellbrook =http://www.wellbrook.uk.com/longwire.html
We have all most likely done it the wrong way more than once . . .http://groups.google.com/group/rec.r...5cc467b35a70d5
*.
*.

- Thanks - I see the Wellbrook diagrams. *Believe me, If I had the
- space, that's how I'd do it. *I have a tiny lot with the house
plopped
- right in the center, power lines fore and aft and neighbors by the
- bushel within a hundred feet. *My wire, by necessity, must go over
my
- rooftop. *In all other respects, it is built roughly as you see in
the
- "good" diagram.
-
- The isolator is a last resort.

BpnJ,
-alternative- Isolator 1:1 [UnUn] Matching Transformer
Wellbrook Antenna Feeder Isolator AFI 5030
http://www.wellbrook.uk.com/pdf/AFI5030A.pdf
http://www.wellbrook.uk.com/antennas...&product_id=56

BpnJ,
-alternative-loop-antenna-set-up-
Shortwave Listener [SWL] Loop Antenna with :
* Four Corners at/near the Lot Line; Centered
around the House.
* 21 Feet Long/Tall Top-Rail for the Four Corners
* Loop Antenna around the Four Corners
* Feed-in-Line from one of the Corners to the
House a few inches under-the-ground.
* Ground each of the pieces of Top-Rail and
place a Ground Rod at the Corner where the
Feed-in-Line comes in from.
* Matching Transformer [MT] -either-
* * MT Up-in-the-Air at the Top of the Top-Rail
* * MT On-the-Ground with 300 Ohm Twin-Lead
from the Loop Antenna Element down to the MT.

The Wire Loop Antenna Element should be 5 Foot
or more out and away from the House/Roof and help
to reduce the Noise Pick-Up from the House itself.
* 5 Foot is good
* * 10 Foot is Better {Twice as Good}
* * * * 20 Foot is GREAT {Four Times as Good}

BpnJ,
TEST : Your Present SWL Antenna when everyone
is away from the House for and overnight.
* Run your Radio/Receiver(s) on Batteries.
* Turn-Off your AC Mains : This Kills all AC Power
to the House -and- Kills all RFI coming from all
those Electrical-Electronic 'Gadgets' in the House.
* Listen to your Radio Overnight and see what you
can hear {RF Signals} and what you can not hear
{RF Noise}. All the other RF Noise is assumed to
be coming from your Next-Door Neighbors and your
nearby Neighborhood [One Block Around You].
* See 'if' you can pin-point any of these RF Noise
Sources coming from a specific Next-Door Neighbor.

Inline Isolators for RFI reduction ?
 

On Jan 16, 10:13*pm, bpnjensen wrote:
On Jan 16, 6:09*pm, John Smith wrote:





On 1/16/2011 5:07 PM, bpnjensen wrote:

...
Short answer - I am getting desperate over the noise level here.
Grasping at straws.

The fellow I spoke to who makes these things said they are best used
as close to the receiver input as possible.

You will certainly need to locate the noise source and place the antenna
as far away as possible and orientate the antenna so the direction
favored by the particular antenna is pointed AWAY form the noise source..
* You will probably want to use a 9:1 balun and use coax for the run
past any noise source and to provide isolation from noise sources in the
home. *A GOOD GROUND on the receiver will serve you well. *If possible,
would also be good to ground the coax braid at the antenna, or run a
wire down to ground as short as possible ...

Regards,
JS

John, thanks - but my whole neighborhood is a noise source. *That's no
joke. *Otherwise, I know all of this already, and have already built
it to the best possible configuration, much as you've described here.- Hide quoted text -

- Show quoted text -

Have you attempted to see if it is coming from the ac 120v outlets?
Quite often THAT is one the biggest source of noise . What
receiver(s) /antenna(s) are you using ?

Inline Isolators for RFI reduction ?
 

On Jan 16, 8:27*pm, wrote:
On Jan 16, 10:13*pm, bpnjensen wrote:









On Jan 16, 6:09*pm, John Smith wrote:

On 1/16/2011 5:07 PM, bpnjensen wrote:

...
Short answer - I am getting desperate over the noise level here.
Grasping at straws.

The fellow I spoke to who makes these things said they are best used
as close to the receiver input as possible.

You will certainly need to locate the noise source and place the antenna
as far away as possible and orientate the antenna so the direction
favored by the particular antenna is pointed AWAY form the noise source.
* You will probably want to use a 9:1 balun and use coax for the run
past any noise source and to provide isolation from noise sources in the
home. *A GOOD GROUND on the receiver will serve you well. *If possible,
would also be good to ground the coax braid at the antenna, or run a
wire down to ground as short as possible ...

Regards,
JS

John, thanks - but my whole neighborhood is a noise source. *That's no
joke. *Otherwise, I know all of this already, and have already built
it to the best possible configuration, much as you've described here.- Hide quoted text -

- Show quoted text -

Have you attempted to see if it is coming from the ac 120v outlets?
Quite often THAT is one the biggest source of noise . *What
receiver(s) /antenna(s) are you using ?

Actually, I know that my outlets/switch boxes are sources of buzzing
RF noise. When I bring an AM radio, especially one with a tunable
loop on it, toward the switches and outlets, the buzzing becomes more
audible. I believe that the house is miswired so that ground and one
hot side may be on the same path (this needs to be fixed).

I do have an RF-born noise filter that I run the 115 VAC through. I
do not get any serious amount of noise from this source (as far as I
can tell) on the radio. The radio I use primarily is an Icom R75
(also an Allied SX-190 and Realistic DX-160). Two external antennas -
the random wire with 9:1 match, and a DX-Ultra (essentially an all-
band dipole, but pretty worthyless on the tropical bands). The worst
noise, by far, is on the lower bands (7 MHz and down). At 15 MHz and
above, the noise is typically minimal and reception is quite good.
The tropical bands are a mess, with an S-7/S-9 noise level most of the
time. I can clean up some of it with my MFJ-1026, but not all.

Inline Isolators for RFI reduction ?
 

On 1/16/2011 9:41 PM, bpnjensen wrote:

...

Do you have above ground power in your area?

Is it possible you are in an area where a "ground loop" is occurring?
How often are the poles grounded? I have seen every pole grounded and
some installations where only 1 out of five poles are grounded ... this
can result in noise ... indeed, tremendous currents can circulate though
the ground ...

Regards,
JS

Inline Isolators for RFI reduction ?
 

On Jan 17, 12:56*am, John Smith wrote:
On 1/16/2011 9:41 PM, bpnjensen wrote:

* ...

Do you have above ground power in your area?

Is it possible you are in an area where a "ground loop" is occurring?
How often are the poles grounded? *I have seen every pole grounded and
some installations where only 1 out of five poles are grounded ... this
can result in noise ... indeed, tremendous currents can circulate though
the ground ...

Regards,
JS

That could be a really atrocious scenario, indeed.

Inline Isolators for RFI reduction ?
 

On Jan 17, 12:41*am, bpnjensen wrote:
On Jan 16, 8:27*pm, wrote:





On Jan 16, 10:13*pm, bpnjensen wrote:

On Jan 16, 6:09*pm, John Smith wrote:

On 1/16/2011 5:07 PM, bpnjensen wrote:

...
Short answer - I am getting desperate over the noise level here.
Grasping at straws.

The fellow I spoke to who makes these things said they are best used
as close to the receiver input as possible.

You will certainly need to locate the noise source and place the antenna
as far away as possible and orientate the antenna so the direction
favored by the particular antenna is pointed AWAY form the noise source.
* You will probably want to use a 9:1 balun and use coax for the run
past any noise source and to provide isolation from noise sources in the
home. *A GOOD GROUND on the receiver will serve you well. *If possible,
would also be good to ground the coax braid at the antenna, or run a
wire down to ground as short as possible ...

Regards,
JS

John, thanks - but my whole neighborhood is a noise source. *That's no
joke. *Otherwise, I know all of this already, and have already built
it to the best possible configuration, much as you've described here.- Hide quoted text -

- Show quoted text -

Have you attempted to see if it is coming from the ac 120v outlets?
Quite often THAT is one the biggest source of noise . *What
receiver(s) /antenna(s) are you using ?

Actually, I know that my outlets/switch boxes are sources of buzzing
RF *noise. *When *I bring an AM radio, especially one with a tunable
loop on it, toward the switches and outlets, the buzzing becomes more
audible. *I believe that the house is miswired so that ground and one
hot side may be on the same path (this needs to be fixed).

I do have an RF-born noise filter that I run the 115 VAC through. *I
do not get any serious amount of noise from this source (as far as I
can tell) on the radio. *The radio I use primarily is an Icom R75
(also an Allied SX-190 and Realistic DX-160). *Two external antennas -
the random wire with 9:1 match, and a DX-Ultra (essentially an all-
band dipole, but pretty worthyless on the tropical bands). *The worst
noise, by far, is on the lower bands (7 MHz and down). *At 15 MHz and
above, the noise is typically minimal and reception is quite good.
The tropical bands are a mess, with an S-7/S-9 noise level most of the
time. *I can clean up some of it with my MFJ-1026, but not all.- Hide quoted text -

- Show quoted text -

Have you tried using a 12v battery as a power source ? This may clear
things up.