Inline Isolators for RFI reduction ?
bpnjensen
well on RX? Such as those sold by Radioworks?
Thanks,
Bruce Jensen
dave
That is complete overkill for receive only.
These are great folks. Whether you buy a half dozen or a pallet, they
treat you right.
http://www.minicircuits.com/cgi-bin/modelsearch?model=T1.18-3-X65%2B&search_type=model
John Smith
Yes, amateurs have been rolling their own for a long time, most often
referred to as "traps" on an amateur antenna. Allows operation over
multiple bands when wire lengths are cut and tuned correctly ...
Regards,
JS
RHF
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.radio.shortwave/msg/735cc467b35a70d5
.
.
bpnjensen
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.
bpnjensen
Thanks, Dave, but I am afraid I don't even know what these devices are
or how they'd be used.
bpnjensen
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.
John Smith
> ...
> 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-antenna-traps-work,88
Regards,
JS
dave
You gotta build a loop.
dave
A tuned loop will give you a fighting chance. I think Ace's bud in
Chitown has one. Peter somebody...
John Smith
> ...
> 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
bpnjensen
Sorry - I know what a trap is - but the thingies Dave linked to do not
look like anything in my experience.
bpnjensen
Maybe so. Know of any good plans for something that will fit on a
pinhead?
bpnjensen
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.
RHF
- 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/antennashop/index.php?route=product/product&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.
.
BpnJ,
We All Live in 'Circles-of-RF-Noise' -so- Think of
"The Distance Away" from Sources-of-Noise
as being your Friend
http://groups.google.com/group/rec.radio.shortwave/msg/b7e9d8e03bb28897
.
BpnJ,
It's A noisy, Noisy. NOISY ! - RF World We Live In . . .
http://groups.google.com/group/rec.radio.shortwave/msg/490a1d5f0791d309
.
.
arthr...@webtv.net
>
> - 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 ?
bpnjensen
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.
John Smith
>> ...
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
arthr...@webtv.net
That could be a really atrocious scenario, indeed.
arthr...@webtv.net
>
> - Show quoted text -
Have you tried using a 12v battery as a power source ? This may clear
things up.
bpnjensen
Good question. I would not be a bit surprised. We have 1950's era
aerial power.
bpnjensen
Not yet, and as RHF also suggested. Maybe worth a try.
RHF
- 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).
BpnJ -First-
Buy a simple to use AC Outlet/Receptacle Tester
http://en.wikipedia.org/wiki/Receptacle_tester
for 3-Wire Outlets : Has 3-Lights to Show Proper
& Improper Wiring of each and every Outlet that
you Test in the House : Do them One-at-aTime
& One Room at a Time : One Room per Day by
the End of Two Weeks 14-Days you should be
Done.
* AC Outlet/Receptacle Tester
http://www.amazon.com/dp/B002LZTKIA
* AC Outlet/Receptacle Tester
http://www.tripplite.com/en/products/model.cfm?txtModelID=3941
* AC Outlet/Receptacle Tester
http://www.acehardware.com/product/index.jsp?productId=3099774
BpnJ -Second-
Next Question : Do You Have 110/120 Volts AC ?
* How to Test for AC Outlet Voltage
http://www.ehow.com/how_2072916_test-ac-voltage.html
* How To Test AC Outlet Voltage
http://www.acmehowto.com/howto/homemaintenance/electrical/outletvoltage.php
* 120 Volts? Usually but not always...
http://www.rocketroberts.com/techart/power.htm
-TIP- The Outlet/Receptacle could be Wired
Right -but- You could have Bad Wiring to the
Outlet and a Voltage Drop down to 85~105 Volts
Another way of doing this is with a Power Strip
http://en.wikipedia.org/wiki/Power_strip
* 6-Outlet Power Strip with 4 Foot Cord
http://www.amazon.com/dp/B00006L4F1
Plug two (2) 100 Watt Incandescent Light Bulbs
in to it using two (2) of these Plug-In Light
Socket Outlet Adapters
http://www.amazon.com/dp/B000VL4CFC
Now you can Check the Voltage at the Outlet
with a 2 Amp Load on it to see if there are any
High Resistance Connections causing a Voltage
Drop.
BpnJ -Third-
LAST : Once all this is Tested and Fixed : You
only have one thing left : Your Service Entrance
Ground. For this Test and Repair you should
Call a Licensed Electrician to do the Work.
http://www.cdc.gov/nceh/publications/books/housing/figure_cha11.htm
-Safety- If the Electrical Service Entrance Ground
is not *R*I*G*H*T* :Then potentially the whole
Electrical System of the House is Unsafe.
-Conclusion-
Once this is all done : You will have the Knowledge
and the Confidence in Knowing that your House's
Electrical System is Wired Correctly and Properly
Grounded. -in-a-word-'safe'-:o)-
The First Rule of Shortwave Radio Listeners [SWLs]
using Outside SWL Antennas is "SAFETY" [.]
hope this helps - iane ~ RHF
.
RHF
- - On Jan 16, 10:05 pm, arthrny...@webtv.net wrote:
- - Have you tried using a 12v battery as a power source ?
- - This may clear things up.
- Not yet, and as RHF also suggested.
- Maybe worth a try.
12 VDC BATTERY POWER [+1 AH] FOR A PORTABLE AM/FM
SHORTWAVE RADIO A/O SOLID-STATE HF RECEIVER :
{DIY & Keeping Under $100} --- Buy One (1) Each :
* 12V 1A Sealed Lead Acid Battery Charger Dual Stage
http://cgi.ebay.com/370421368126
Regular Charge with a Trickle Charge
* @ +1 AH -use- 12V 12AH Sealed Lead Acid {SLA} Battery
http://cgi.ebay.com/380184942669
-or- @ +1.5 AH -use- 12V 18AH Sealed Lead Acid {SLA} Battery
http://cgi.ebay.com/270661501864
-or- +2AH -use- 12V 26AH Sealed Lead Acid {SLA} Battery
http://cgi.ebay.com/220694638387
NOTE : Anything more/beyond this +2 AH Rating
-and- IMHO you should start looking at 12V Motorcycle
Batteries and 12V Car Chargers.
-as-a-lower-cost-alternative-
* DPDT Knife Switch
http://cgi.ebay.com/290523172495
* 6-Outlet Switched Power Strip with 6 Foot Cord
* Plastic Tube or Wooden Box [1 Foot Cube] to put it all in.
This should run your Icom IC-R75 for ~8 Hours :
Charging for 16 Hours with 8 Hour Run Time at +1 AH.
-also- Runs the Grundig Satellit 800M Radio
for around the same time.
Wiring the DPDT Knife Switch :
Center 'Blades' is the 12 VDC Battery
One-Side Prongs is AC Charger {Charging}
Other-Side Prongs is Radio "ON*" {In-Use}
* When Knife Blade is 'switched' to Radio "ON"
Turn the AC Power Strip "Off" -or- Un-Plug
the AC Power Strip from the Wall Outlet.
Powering "UP" the Radio [Turning "On" Steps] :
First : AC Switch "Off"
Second : Knife Switch to Radio
Third [LAST] : Turn "On" the Radio/Receiver
NOTE : Reverse the Steps to Power "Down"
the Radio [Turning "Off"]
Going Way 'Over-Board' :
# 1 - Put a Three (3) Clamp-On Ferrite Cores*
on the AC Power Strip Cord at each end
of the Cord and in the Middle too.
# 2 - Put a Two (2) Clamp-On Ferrite Cores
on the DC Power Cord Going to the Radio
at each end of the Cord.
# 3 - Put One Each Clamp-On Ferrite Core on
both the Negative(-) and Positive(+) DC Power
Cord Lines {Wires} about an Inch or two from
the Battery Going to the Radio.
* Clamp-On Ferrite Cores
http://www.amazon.com/dp/B0002MQGE0
Over-Board-R-Us : Yes I Did All Three ;;-}} ~ RHF
There is one more Advantage of this 12 VDC
Battery Power System :Solar Charging with a
12 VDC {18 VDC} Solar Panel. :o)
.
.
D. Peter Maus
Your wire is likely pulling noise out of your house. If you can't
move the wire away from the house, then you do have a bit of a
challenge. And isolator will only produce a cleaner path for the
radiated noise picked up by your antenna to follow to your receiver.
That said, the isolator you're looking at is far more expense
than performance for your application. You can do as much with a 9:1
transformer, either prepackaged from Mini-Circuits, or home made by
winding around an Amidon toroid worked against an earth ground. Or
you could pickup the RF Systems Magnetic Longwire Balun. Also more
expense than you need, but it's a good match for what you're trying
to achieve, and durable in construction if you're not comfortable
growing your own. Anything you want to do, though, will require a
good earth ground.
Something like the Wellbrook Loop would also be a good choice.
Costly, of course. Solid performance, though. And unobtrusive. Or,
if you can get away with it, an RF Systems MTA. Now, I have one, and
I use it regularly. In a high noise environment, it's very
effective. But, man made noise, radiated from the electronics and
other appliances in the home...it's not so effective against that.
MTA, like the Wellbrook, or the isolation systems you're
considering, will be most effective against high levels of
atmospheric noise. Less so with man made noise radiated into your
antenna space.
dave
I linked to transformers, which was the original subject (Radiowavs
Isolators). Minicircuit transformers are a fraction of the cost of
BalUns, UnUns, etc. and all you have to do is build an enclosure out of
a damn Sucrets tin.
dave
http://www.frontiernet.net/~jadale/Loop.htm
The cool thing about loops is that they come in all sizes. If you are
just receiving the possibilities are virtually endless. I assume you've
already tried phased antennas.
dave
Have you tried clamp-on ferrite beads on your AC Mains, right at the
meter? They have to be the right ferrite mix for low HF and you may need
to use more than 1 per leg. That will get all the dimmer buzz and
switchmode whistles from the power lines off your home AC.
I can vouch for these two papers as being very informative without
getting too academic:
http://www.audiosystemsgroup.com/RFI-Ham.pdf
http://www.audiosystemsgroup.com/SAC0305Ferrites.pdf
RHF
Here is a 1:1 Line Isolator
52 Ohms : Unbalanced Input -to- Unbalanced Output
SO239 -to- SO239 for 1.5 to 55 MHz
http://www.packetradio.com/catalog/index.php?main_page=product_info&cPath=11&products_id=2234
.
.
dave
>
> Here is a 1:1 Line Isolator
> 52 Ohms : Unbalanced Input -to- Unbalanced Output
> SO239 -to- SO239 for 1.5 to 55 MHz
> http://www.packetradio.com/catalog/index.php?main_page=product_info&cPath=11&products_id=2234
> .
> .
hmmmmm
dxAce
will be solved by getting your local power officials to resolve issues with
the power lines in your area.
John Smith
ROFLOL ...
I thought it was bad when I seen those confused by the difference of rf
transformers to baluns/unun (TLTs) ... now we have a third term thrown
in that must mean "Isolation Transformer."
No wonder there is so much confusion out there ... so now we have rf
transformers, baluns, ununs, isolation transformers, transmission line
transformers and auto-transformers all being covered by the term "line
isolator."
It is going to fun watching two separate people talking about "line
isolators" ... ROFLOL
Regards,
JS
John Smith
> I don't think that your RFI issues are going to be solved by isolators. They
> will be solved by getting your local power officials to resolve issues with
> the power lines in your area.
>
> bpnjensen wrote:
>
I do believe if his antenna is resonate he will increase the signal(s)
which are resonate to the background noise ... you post is very
deceiving ...
Regards,
JS
dxAce
John Smith wrote:
k00k
John Smith
> ...
> ROFLOL ...
>
> I thought it was bad when I seen those confused by the difference of rf
> transformers to baluns/unun (TLTs) ... now we have a third term thrown
> in that must mean "Isolation Transformer."
>
> No wonder there is so much confusion out there ... so now we have rf
> transformers, baluns, ununs, isolation transformers, transmission line
> transformers and auto-transformers all being covered by the term "line
> isolator."
>
> It is going to fun watching two separate people talking about "line
> isolators" ... ROFLOL
>
> Regards,
> JS
Oh yeah, and I forgot about "antenna traps", you can toss them in with
line isolators also ...
Regards,
JS
bpnjensen
I use phased antennas, and they work to a point.
bpnjensen
> On Jan 16, 10:39 pm, bpnjensen <bpnjen...@yahoo.com> wrote:
>
> - - On Jan 16, 10:05 pm, arthrny...@webtv.net wrote:
> - - Have you tried using a 12v battery as a power source ?
> - - This may clear things up.
>
> - Not yet, and as RHF also suggested.
> - Maybe worth a try.
>
> 12 VDC BATTERY POWER [+1 AH] FOR A PORTABLE AM/FM
> SHORTWAVE RADIO A/O SOLID-STATE HF RECEIVER :
> {DIY & Keeping Under $100} --- Buy One (1) Each :
>
> Regular Charge with a Trickle Charge
>
> -or- @ +1.5 AH -use- 12V 18AH Sealed Lead Acid {SLA} Batteryhttp://cgi.ebay.com/270661501864
> -or- +2AH -use- 12V 26AH Sealed Lead Acid {SLA} Batteryhttp://cgi.ebay.com/220694638387
>
> NOTE : Anything more/beyond this +2 AH Rating
> -and- IMHO you should start looking at 12V Motorcycle
> Batteries and 12V Car Chargers.
> -as-a-lower-cost-alternative-
>
>
> Over-Board-R-Us : Yes I Did All Three ;;-}} ~ RHF
>
> There is one more Advantage of this 12 VDC
> Battery Power System :Solar Charging with a
> 12 VDC {18 VDC} Solar Panel. :o)
> .
> .
Thanks - I will look into this...
bpnjensen
Thanks - I will look into these.
bpnjensen
> .
> .
Thanks - this is, in fact, quite close to what I have been looking at.
bpnjensen
Well, that's possible too. Placing the radio on a 12v battery at
least will tell for certain whether the bulk of the noise is coming
through the wires or through the antenna.
Joe from Kokomo
> Well, that's possible too. Placing the radio on a 12v battery at
> least will tell for certain whether the bulk of the noise is coming
> through the wires or through the antenna.
Not sure if anyone mentioned this or not...but while you are operating
the radio on 12 volts, kill ALL the AC power to your house at the panel.
This will eliminate the possibility that the enemy is you. Or tell you
that you -do- have a problem on your property.
If your house is clean, try driving around the neighborhood to search
for the noise source, using a portable radio, preferably shortwave,
tuned to the frequency where you are experiencing the problem.
Otherwise, a plain old AM transistor radio will work.
RHF
JS,
But it is 'by-design' a "Non-Resonate" Broadband
Shortwave Radio Listener's [SWL] Antenna using
a Broadbanded* 9:1 Matching Transformer. ~ RHF
* Frequency Range : 500kHz to 30 MHz
Five Basic Steps to Better Shortwave Radio Listening [SWL] :
1 - Build the Best Antenna and Ground System you can.
{Given Your Location, Conditions and Circumstances}
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.radio.shortwave/msg/735cc467b35a70d5
.
2 - Best 'Radio Shack' {Radio Room} Electrical System
and Grounding that you can achieve.
-or- 12 VDC Battery Power [1 AH] for a 'portable' AM/FM
Shortwave Radio a/o Solid-State HF Receiver
http://groups.google.com/group/rec.radio.shortwave/msg/7c122d57f21c667c
.
3 - Resolve the Electrical and RF Noise Issues
in your House and on your property.
-read- Ensuring You House's Electrical System
is Wired Correctly and Properly Grounded
http://groups.google.com/group/rec.radio.shortwave/msg/1062dc8426d197b8
.
4 - Work 'with' Your Immediate Neighbors to Clean-Up
Their RF Noise Issues.
5 - Deal with the Power Company with Identified RF
Noise Sources -if- You can find them.
it ain't easy -but- it is doable - iane ~ RHF
.
.
RHF
> On 1/17/2011 1:27 PM, dave wrote:
>
> > On 01/17/2011 01:15 PM, RHF wrote:
>
> >> Here is a 1:1 Line Isolator
> >> 52 Ohms : Unbalanced Input -to- Unbalanced Output
> >> SO239 -to- SO239 for 1.5 to 55 MHz
>
> >> .
> >> .
> > hmmmmm
>
> ROFLOL ...
>
> I thought it was bad when I seen those confused by the difference of rf
> transformers to baluns/unun (TLTs) ... now we have a third term thrown
> in that must mean "Isolation Transformer."
>
> No wonder there is so much confusion out there ... so now we have rf
> transformers, baluns, ununs, isolation transformers, transmission line
> transformers and auto-transformers all being covered by the term "line
> isolator."
>
> It is going to fun watching two separate people talking about "line
> isolators" ... ROFLOL
>
> Regards,
> JS
JS,
To Sell the Steak : It's Got To Have SIZZLE !
With most commercial products : It's about Marketing
and Distinguishing your Product in the Market Place.
-hence- MLB = Magnetic Longwire Balun
http://www.rf-systems.nl/direct/home_2.htm
http://www.palomar-engineers.com/MLB-1/mlb-1.html
-and- UMB = Universal Magnetic Balun
http://www.wellbrook.uk.com/antennashop/index.php?route=product/product&product_id=55
-also- LIM = Longwire Impedance Matcher
http://www.durhamradio.com/lim-longwire-impedance-matcher-ontario-canada.html
-one-more- LWA = Long Wire Antenna Adapter
http://www.grove-ent.com/WR0130.html
.
Magnetic Longwire Balun [MLB] : Not Really A 'Balun'
http://www.hard-core-dx.com/nordicdx/antenna/feed/magbal2.html
.
-the-acronym-name-game- ~ RHF
.
.
John Smith
> ...
> But it is 'by-design' a "Non-Resonate" Broadband
> Shortwave Radio Listener's [SWL] Antenna using
> a Broadbanded* 9:1 Matching Transformer. ~ RHF
> * Frequency Range : 500kHz to 30 MHz
> ...
I don't know what antenna you are speaking of. But, the original bent
of this thread started out with "line isolators", actually traps meant
to resonate a single antenna on multiple bands ... usually a dipole,
however, can be used on monopoles also ...
Regards,
JS
RHF
> On 1/18/2011 6:56 AM, RHF wrote:
>
> > ...
> > But it is 'by-design' a "Non-Resonate" Broadband
> > Shortwave Radio Listener's [SWL] Antenna using
> > a Broadbanded* 9:1 Matching Transformer. ~ RHF
> > * Frequency Range : 500kHz to 30 MHz
> > ...
Five Basic Steps to Better Shortwave Radio Listening [SWL]
.
- I don't know what antenna you are speaking of.
- But, the original bent of this thread started out
- with "line isolators", actually traps
- meant to resonate a single antenna on multiple bands
- ... usually a dipole,
- however, can be used on monopoles also ...
-
- Regards,
- JS
* * * Here is the 'Original' Post * * *
Inline Isolators for RFI Reduction ? -by- bpnjensen
http://groups.google.com/group/rec.radio.shortwave/msg/c5226b3b6ab4ead7
-wrt- Radioworks "Line Isolator"
http://www.radioworks.com/
CLICK-ON : "Line Isolators" [Button] and
Read what Radioworks has to say -wrt-
* The Ground Loop Solution
* Line Isolator
* How it works
.
.
A One-to-One [1:1] in-line Transformer* to reduce
'common mode' RF Noise migration out from the
House's AC Mains to the Antenna; and from the
the Antenna back into the Radio/Receiver as Noise.
* -aka- Common Mode Choke
http://en.wikipedia.org/wiki/Choke_%28electronics%29
.
=WRT= Common Mode Noise Isolation
http://www.w8ji.com/common-mode_noise.htm
.
-read- Grounding is Key to Good Reception
-by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/ground/ground2.html
.
A Ham's Guide to RFI, Ferrites, Baluns, and Audio Interfacing
-by- Jim Brown [K9YC]
http://www.audiosystemsgroup.com/RFI-Ham.pdf
=Source=©= Audio Systems Group, Inc.
http://audiosystemsgroup.com
hope this helps - iane ~ RHF
.
.
Just for BpnJ : here is another Common-Mode 'Choke'
{RF Noise Isolator} for Antenna Feed-in-Lines [$50]
WinRadio WR-CMC-30 Common-Mode Choke
http://www.winradio.com/home/cmc-30.htm
-source-
https://robogroup.com/winradio/cgi-bin/wrshop.cgi?antacc!Antenna%20accessories
.
.
John Smith
> ...
Well, you are correct, I just looked at the line isolators on the
radioworks page ... they show 3 of them in line ... when I had first
read some of their "snake oil pitches" and talking about mulitple units,
I interpreted the description as "traps." The diagram on their pages
makes it clear they are either rf transformers or baluns/ununs ...
I stand corrected ...
Regards,
JS
bpnjensen
Actually, no, and I am sorry if there was a misunderstanding - I meant
an inline (in the coax) RFI reduction system.
bpnjensen
> bpnjensen wrote:
> >Placing the radio on a 12v battery at
> >least will tell for certain whether the bulk of the noise is coming
> >through the wires or through the antenna.
>
> easier than coming up with a battery.
Well - actually I have done this before. The radio gets VERY quiet
when I do this. A good sign, perhaps?
John Smith
> ...
> Actually, no, and I am sorry if there was a misunderstanding - I meant
> an inline (in the coax) RFI reduction system.
Baluns/ununs really are NOT an RFI reduction system. They provide
proper impedance matching between antenna and feedline. Coax, with an
rf choke (can be a balun/unun) allows the feedline to run though noisy
areas and not pick up the noise there, such as when it enters a house
with noise present.
Baluns/ununs/rf-transformers, because of the use in gaining a superior
match (transfer of signal energy) improves signal to noise ratio, in
most instances, and this can appear to be functioning as a "RFI
reduction system."
Some useful links:
http://users.belgacom.net/hamradio/schemas/Magnetic%20Longwire%20Balun_MLB.htm
http://www.qsl.net/ta1dx/amator/broadband_baluns.htm
http://www.k3hkr.com/Baluns101.html
http://vk5ajl.com/projects/baluns.php
http://g4oep.atspace.com/balun/balun.htm
Regards,
JS
dave
No such thing. Those isolators just keep hum away. Hum is not your
problem. You are likely hearing triac noise (dimmer buzz, halogen
torchieres, waterbed heaters, etc.) over the air. It is coming in or
power lines and RF chokes on those lines will stop it at the electrical
box. But because you have overhead mains that probably won't help
enough. You may be able to reduce it enough to get better results from
your phase canceller. I'm peabrainstorming here...
John Smith
> ...
> No such thing. Those isolators just keep hum away. Hum is not your
> problem. You are likely hearing triac noise (dimmer buzz, halogen
> torchieres, waterbed heaters, etc.) over the air. It is coming in or
> power lines and RF chokes on those lines will stop it at the electrical
> box. But because you have overhead mains that probably won't help
> enough. You may be able to reduce it enough to get better results from
> your phase canceller. I'm peabrainstorming here...
What dave was attempting to describe is common mode noise. This is
probably at least a portion of your noise, best for you to decide:
http://www.w8ji.com/common-mode_noise.htm
http://www.dxengineering.com/TechArticles.asp?ID={3F341778-BFE9-4988-AD87-142FD1E04EB2}
http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf
http://www.hard-core-dx.com/nordicdx/antenna/feed/balun3.html
The links and scientific/technical papers on Common Mode Noise are
simply without end. Feel free to use a search engine and find material
which is easy for you to digest ...
Regards,
JS
bpnjensen
> On 1/18/2011 10:44 AM, bpnjensen wrote:
>
> > ...
> > Actually, no, and I am sorry if there was a misunderstanding - I meant
> > an inline (in the coax) RFI reduction system.
>
> Baluns/ununs really are NOT an RFI reduction system. They provide
> proper impedance matching between antenna and feedline. Coax, with an
> rf choke (can be a balun/unun) allows the feedline to run though noisy
> areas and not pick up the noise there, such as when it enters a house
> with noise present.
>
> Baluns/ununs/rf-transformers, because of the use in gaining a superior
> match (transfer of signal energy) improves signal to noise ratio, in
> most instances, and this can appear to be functioning as a "RFI
> reduction system."
>
>
> Regards,
> JS
OK, understood, but I have always thought (based on what I have read)
that one of these matching transformers, properly deisgned and
grounded, can bleed off some noise to ground. Am I misled?
bpnjensen
>
> - Show quoted text -
OK, good info. Do you think a magnetic loop could diminish reception
of the RFI from the overheads? Like, as Peter M. suggests, a
Wellbrook?
D. Peter Maus
Local environmental noise, and static, yes. Man made noise, or
noise radiated into the antenna space, not so much, no.
A properly designed matching transformer will improve the
transfer of antenna output to the receiver. And it will help drain
off static buildup on the antenna, and help reduce the noise floor.
But, if noise is being radiated into the air, as from powerlines,
digital toys, and dimmers and similar sources, and your antenna is
picking that up, it will depend on the antenna's ability to
discriminate between desired and undesired frequencies whether or
not you see a reduction in undesired signals.
It sounds as though much of your noise problem is related to your
connection to the mains. Mains borne noise is a big problem in radio
hobbycraft. Most of the noise in my own area is brought in through
the mains. The remainder is radiated from the hundreds of devices
throughout the neighborhood.
It's possible, though a PITA to do so, to bypass the mains with
safety caps between .1 - .01mfd (safety caps are essential, here,
for fire prevention) to reduce the irregular impulses on the line.
And isolation transformer, balanced to ground will also produce
significant results in reducing your noise, but that can be expensive.
Your least difficult path may be in isolating your radios from
the mains, entirely, and move to battery power.
John Smith
> ...
> OK, understood, but I have always thought (based on what I have read)
> that one of these matching transformers, properly deisgned and
> grounded, can bleed off some noise to ground. Am I misled?
NO, you are not mislead. They are death on common mode noise. If your
problem is common mode noise they work like a miracle ... the signal to
noise boost the match ain't bad either ...
Regards,
JS
dave
I have heard amazing things. That model is pricey. You can build an
experimental loop for the price of a variable capacitor from MFJ and
some scrap coax.
dave
series with your mains. Shunt caps are scary. MOVs, sure.
bpnjensen
> On 1/18/11 16:05 , bpnjensen wrote:
>
>
>
>
>
>
>
>
>
> > On Jan 18, 10:57 am, John Smith<assemblywiz...@gmail.com> wrote:
> >> On 1/18/2011 10:44 AM, bpnjensen wrote:
>
> >>> ...
> >>> Actually, no, and I am sorry if there was a misunderstanding - I meant
> >>> an inline (in the coax) RFI reduction system.
>
> >> Baluns/ununs really are NOT an RFI reduction system. They provide
> >> proper impedance matching between antenna and feedline. Coax, with an
> >> rf choke (can be a balun/unun) allows the feedline to run though noisy
> >> areas and not pick up the noise there, such as when it enters a house
> >> with noise present.
>
> >> Baluns/ununs/rf-transformers, because of the use in gaining a superior
> >> match (transfer of signal energy) improves signal to noise ratio, in
> >> most instances, and this can appear to be functioning as a "RFI
> >> reduction system."
>
> >> Some useful links:http://users.belgacom.net/hamradio/schemas/Magnetic%20Longwire%20Balu...
>
Thanks, Peter - This may be all true - but for the record, with the
radios plugged in, I disconnected the antennas and kept the grounds
connected. The radios got very quiet; based on this, I don't think
it's the mains.
FWIW, I have an RFI filter on the 115 VAC - this item:
ICE:
http://www.iceradioproducts.com/images/QSTACfiltersarticle.pdf
The difference between using it and not using it is slight, but
noticeable.
bpnjensen
> of the noise entry point to the radio.
> At least you know it's not a defective radio,
> as much as a challenging listening location.
> I live in an inner-city area and my best listening comes
> when I take the portable to a local park
> away from the commercial establishments around here.
>
> Eton - E1 with:
> Grundig AN-200 tunable loop for AMBCB
> 27 foot Radio Shack reel antenna for HF/SWL
> Built in internal telescoping whip for FMBCB.
> It all fits in a padded laptop case I got at a thrift store.
> ...and no coohoo, it wasn't 'goodwill'.
Yeah, not surprised Bob. My radios are all good, I am quite certain.
Being able to get them away from this RF mess to a quite location.
Maybe I'll try to match up the astronomy sessions with the radios.
bpnjensen
> On 01/18/2011 02:17 PM, D. Peter Maus wrote:
>
>
>
>
>
>
>
> > On 1/18/11 16:05 , bpnjensen wrote:
> >> On Jan 18, 10:57 am, John Smith<assemblywiz...@gmail.com> wrote:
> >>> On 1/18/2011 10:44 AM, bpnjensen wrote:
>
> >>>> ...
> >>>> Actually, no, and I am sorry if there was a misunderstanding - I meant
> >>>> an inline (in the coax) RFI reduction system.
>
> >>> Baluns/ununs really are NOT an RFI reduction system. They provide
> >>> proper impedance matching between antenna and feedline. Coax, with an
> >>> rf choke (can be a balun/unun) allows the feedline to run though noisy
> >>> areas and not pick up the noise there, such as when it enters a house
> >>> with noise present.
>
> >>> Baluns/ununs/rf-transformers, because of the use in gaining a superior
> >>> match (transfer of signal energy) improves signal to noise ratio, in
> >>> most instances, and this can appear to be functioning as a "RFI
> >>> reduction system."
>
> >>> Some useful
> >>> links:http://users.belgacom.net/hamradio/schemas/Magnetic%20Longwire%20Balu...
>
Thanks - Maybe, but I think ferrites on the RF cables might be more
critical than on the power cables. The radios are nice and quite when
I disconnect the antennae; no noise level at all even with the
multiple preamps all the way up.
D. Peter Maus
I had a noise I couldn't get rid of, a few years ago. Everything
pointed to some radiated phenomenon. Tried disconnecting the antenna.
Things got very quiet. Finally tracked it down with a Zenith transistor
radio. It was, in fact, noise on the mains, radiated into the antenna
space. Filtered the line and modded an offending device that was putting
the spike on the line. Cleaned it right up.
A transitor radio can be useful in tracking down the source. Follow
the noise, turn off each implement one at a time, and you'll find the
source or sources of noise.
You sound like you're living in the noise equivalent of the Little
Big Horn.
>
> FWIW, I have an RFI filter on the 115 VAC - this item:
>
> ICE:
>
> http://www.iceradioproducts.com/images/QSTACfiltersarticle.pdf
>
> The difference between using it and not using it is slight, but
> noticeable.
Such a device is best used as close to the source as practical.
John Smith
>> ...
GAWD!
And, I thought I had it bad ...
Regards,
JS
bpnjensen
This one is plugged into the wall between the radio and the socket.
Can you get any closer than that?
I also know factually that a MW radio brought near things like wall
switches and plugs results in a 60 Hz hum on the radio. It is really
noticeable with a little loop antenna swiveled around - whenever it
points to the wall switch, you hear that hum. The hum is not apparent
on the SW bands at all; but on powerhouse MW stations like KGO locally
here, the hum is solidly behind the audio.
bpnjensen
> bpnjensen wrote:
> >Maybe I'll try to match up the astronomy sessions with the radios.
>
> up to the local mountains or over to the desert for an evening
> of various activities, astronomy included.
> We would routinely take a load of optical gear plus star charts,
> GPS units plus topo charts, amateur radio gear for tactical coordination,
> as well as a few firearms, pyrotechnical devices, night vision viewers,
> and so on. We had met through mutual interest in scanner/SWL activities.
BIG sigh - that sounds wonderful!
bpnjensen
> D. Peter Maus wrote:
>
> > You sound like you're living in the noise equivalent of the Little
> >Big Horn.
>
> Or so it seemedhttp://img.myph.us/Ar9.jpg
> From the left is a Butternut 80/40 vertical then an Imax 2000 (CB antenna)
> for 10, 12, 15 and also mounted on the back porch a Diamond V2000 for
> 6, 2, 440. then on the roof is a discone plus some UHF WX transponders.
> In addition to Cox and Ma Bell were 4kv, 12kv distribution feeders,
> and above that a 138kv tie line (not visible in pic). All of that wire either
> radiated its own noise or parasitically re-radiated noise of the others
> so it was often, but not always, difficult to get a precise source to use in the
> phase noise canceler (ANC-4).
> The TV antenna was useful to get OTA LA stations like KCAL9,
> SoCal's premier car chase station. <g>
This looks bad, worse than my situation. I just have the local
residential feeder out front, probably 12 kv, and a set of parallel
feeders in back that probably range up to 138 kv that serves the
industrial park 500 feet west of me. I can often reduce noise from
one source with my MFJ-1026 (similar to the ANC-4), but just the one.
I hate the idea of piling up multiple MFJs and antennae to try to
catch all of the sources.
There are some high-tension lines out about 1/2 mile west or so, but
they are pretty far. They audibly crackle and snap all the time,
though, whenever I ride my bike past them.
arthr...@webtv.net
> >Big Horn.
>
> Or so it seemedhttp://img.myph.us/Ar9.jpg
> From the left is a Butternut 80/40 vertical then an Imax 2000 (CB antenna)
> for 10, 12, 15 and also mounted on the back porch a Diamond V2000 for
> 6, 2, 440. then on the roof is a discone plus some UHF WX transponders.
> In addition to Cox and Ma Bell were 4kv, 12kv distribution feeders,
> and above that a 138kv tie line (not visible in pic). All of that wire either
> radiated its own noise or parasitically re-radiated noise of the others
> so it was often, but not always, difficult to get a precise source to use in the
> phase noise canceler (ANC-4).
> The TV antenna was useful to get OTA LA stations like KCAL9,
> SoCal's premier car chase station. <g>
Oh,that's why some people started using alumium siding ! It is almost
a Faraday cage...
Karl Mauritania
bpnjensen wrote:
You need to flee your present location.
Karl Knows
dave
> Thanks, Peter - This may be all true - but for the record, with the
> radios plugged in, I disconnected the antennas and kept the grounds
> connected. The radios got very quiet; based on this, I don't think
> it's the mains.
>
> FWIW, I have an RFI filter on the 115 VAC - this item:
>
> ICE:
>
> http://www.iceradioproducts.com/images/QSTACfiltersarticle.pdf
>
> The difference between using it and not using it is slight, but
> noticeable.
http://www.radioshack.com/product/index.jsp?productId=2103222
[read reviews]
dave
>
> Thanks - Maybe, but I think ferrites on the RF cables might be more
> critical than on the power cables. The radios are nice and quite when
> I disconnect the antennae; no noise level at all even with the
> multiple preamps all the way up.
Maybe you should just use 50 Ohm resistors in lieu of antennas. Very low
VSWR; should work great.
dave
> The TV antenna was useful to get OTA LA stations like KCAL9,
> SoCal's premier car chase station.<g>
KCAL is where KCBS puts all their ghetto stuff.
dave
>
> Oh,that's why some people started using alumium siding ! It is almost
> a Faraday cage...
Around here all the houses are stucco, with steel lath. Nothing
penetrates below about 400 MHz, when the windows start admitting
electrical fields.
RHF
- siding ! It is almost a Faraday cage...
A Faraday Cage {Copper Kettle} works both ways.
.
RHF
> On Jan 18, 10:57 am, John Smith <assemblywiz...@gmail.com> wrote:
>
>
>
> > On 1/18/2011 10:44 AM, bpnjensen wrote:
>
> > > ...
> > > Actually, no, and I am sorry if there was a misunderstanding - I meant
> > > an inline (in the coax) RFI reduction system.
>
> > Baluns/ununs really are NOT an RFI reduction system. They provide
> > proper impedance matching between antenna and feedline. Coax, with an
> > rf choke (can be a balun/unun) allows the feedline to run though noisy
> > areas and not pick up the noise there, such as when it enters a house
> > with noise present.
>
> > Baluns/ununs/rf-transformers, because of the use in gaining a superior
> > match (transfer of signal energy) improves signal to noise ratio, in
> > most instances, and this can appear to be functioning as a "RFI
> > reduction system."
>
> > Some useful links:http://users.belgacom.net/hamradio/schemas/Magnetic%20Longwire%20Balu...
>
> > Regards,
> > JS
>
> OK, understood, but I have always thought (based on what I have read)
> that one of these matching transformers, properly deisgned and
> grounded, can bleed off some noise to ground. Am I misled?
The 'concept' is that the Feed-in-Line "Inline Isolator"
[1:1 Transformer] is in the Radio Shack -or- at the point
the Feed-in-Line enters the House/Building.
Mount the "Inline Isolator" directly on a Ground Rod
right outside the Radio Shack Window.
http://www.wellbrook.uk.com/longwire.html
Placement at this point prevents the AC Line Noise
and other RFI Noises in the House from 'migrating' out
along the Coax to the Antenna|End; and then ?reflecting?
back from the Antenna along the Coax back into the
Radio Shack and into the Radio/Receiver.
iane ~ RHF
.
.
D Peter Maus
It needs to be closer to the noise source...the device that's putting
the noise on the lines. That may be difficult.
>
> I also know factually that a MW radio brought near things like wall
> switches and plugs results in a 60 Hz hum on the radio. It is really
> noticeable with a little loop antenna swiveled around - whenever it
> points to the wall switch, you hear that hum. The hum is not apparent
> on the SW bands at all; but on powerhouse MW stations like KGO locally
> here, the hum is solidly behind the audio.
That sounds like it's not just an A/C borne problem. That sounds like
you've got some RF in there, as well, mixing with other signals.
Probably rectified through a poor mechanical connection between metal
components of a nearby structure, or your house. A local FM would create
this collection of symptoms, too.
How far is KGO from your property?
bpnjensen
wrote:
>
> - Show quoted text -
If only I could.
bpnjensen
>
> - Show quoted text -
KGO's 50 kW transmitter is about 5-6 miles, along the bay shore. That
is not all - I also have two additional 50 kW xmtrs within 2 miles of
the house, also along the bay shore. Their signals are potent, to say
the least. I hear them pretty easily with no antenna attached and the
preamps off.
To be clear - the KGO signal I refer to is on their normal frequency
of 810 kHz. As far as I can tell, I get no serious harmonics from
them. WRT to the other two stations, well - harmonics out the ying-
yang...plus a few mixing products. As far as I know, we have no local
FM xmtrs.
bpnjensen
Thanks - I have a few of those on already - maybe I need more. I'd
buy a batch of 100 if they were not so pricey and put them on
everything.
bpnjensen
>
> Placement at this point prevents the AC Line Noise
> and other RFI Noises in the House from 'migrating' out
> along the Coax to the Antenna|End; and then ?reflecting?
> back from the Antenna along the Coax back into the
> Radio Shack and into the Radio/Receiver.
>
> iane ~ RHF
> .
>
> - Show quoted text -
Yepp, that seems to be the theory. Might be worth a shot.
dxAce
bpnjensen wrote:
I understand.
D. Peter Maus
You don't need harmonics for 810 to be a problem. It sounds like
you're getting mix products into your radio. It also sounds like
you're getting RF into your radio through something other than your
antennna. In such an RF field of such intensity, that's not
surprising. I've got a 5000w local AM about 7 miles from me. That
creates enough chaos.
Ferrite cores will help to attenuate some of the leakage into
your radio. A core at the radio end, and at the far end will go
along way to eliminating the hum you describe.
But mix products are difficult to track down, let alone
eliminate. You'll need to find, and isolate the point at which
rectification is taking place, and that could be ANYWHERE...wherever
metal components in any structure touch, you can get rectification,
which will product mix products from the environmental RF. It took
me a couple of years to finally track down and eliminate the mix
products being generated on my property. Padding down the antenna
input also helped.
You really ARE in the Little Big Horn for noise and interference.
John Smith
> Question to those who may have used one - Do inline isolators work
> well on RX? Such as those sold by Radioworks?
>
> Thanks,
> Bruce Jensen
>
It sounds like, if you use an outdoor antenna, you need a 9:1 balun/unun
(depending on antenna design/length) at the point where the feed line
feeds the antenna, with the shield grounded at this point to a good
earth ground.
Next, a 1:1 unun (50 to 50, or 75 to 75, ohm) between the coax and the
receiver, with a good earth ground on the receiver.
This should remove any common mode noise on the shield of the coax.
This is what I use ...
If you use a balanced antenna, you need a balun at the feedline where it
feeds the antenna, if you use a longwire/unbalanced-antenna, you need a
unun at this point.
Regards,
JS
dave
>
> But mix products are difficult to track down, let alone eliminate.
> You'll need to find, and isolate the point at which rectification is
> taking place, and that could be ANYWHERE...wherever metal components in
> any structure touch, you can get rectification, which will product mix
> products from the environmental RF. It took me a couple of years to
> finally track down and eliminate the mix products being generated on my
> property. Padding down the antenna input also helped.
>
> You really ARE in the Little Big Horn for noise and interference.
>
A 20 dB pad will help the swamping. Have you tried an MFJ-956 preselector?
RHF
> On Jan 19, 5:57 am, dave <d...@dave.dave> wrote:
>
>
>
> > On 01/18/2011 07:59 PM, bpnjensen wrote:
>
> > > Thanks, Peter - This may be all true - but for the record, with the
> > > radios plugged in, I disconnected the antennas and kept the grounds
> > > connected. The radios got very quiet; based on this, I don't think
> > > it's the mains.
>
> > > FWIW, I have an RFI filter on the 115 VAC - this item:
>
> > > ICE:
>
> > >http://www.iceradioproducts.com/images/QSTACfiltersarticle.pdf
>
> > > The difference between using it and not using it is slight, but
> > > noticeable.
>
> >http://www.radioshack.com/product/index.jsp?productId=2103222
>
> > [read reviews]
>
- buy a batch of 100 if they were not so pricey and put them on
- everything.
BpnJ - Take a look for 'Ferrite Core' on eBay :
Here is a LOT of Twenty with Two Lots left
20 Clamp-On Ferrite EMI-RFI Suppressors
http://cgi.ebay.com/330519446693
Prices out to about $1.50 Each
Here is a LOT of Ten with Ten Lots left
10x TDK Filter Ferrite Core 9 mm Clip On
http://cgi.ebay.com/310273949954
Prices out to about $1.30 Each
Here is a LOT of Ten with Ten Lots left
10 Ferrite Snap-On EMI Noise Core Filter
in 3 Sizes {Fits All}
http://cgi.ebay.com/160403444626
Prices out to about $1.50 Each
hope this helps - iane ~ RHF
.
.
RHF
>
>
>
> > On 01/18/2011 07:59 PM, bpnjensen wrote:
>
> > > Thanks, Peter - This may be all true - but for the record, with the
> > > radios plugged in, I disconnected the antennas and kept the grounds
> > > connected. The radios got very quiet; based on this, I don't think
> > > it's the mains.
>
> > > FWIW, I have an RFI filter on the 115 VAC - this item:
>
> > > ICE:
>
> > >http://www.iceradioproducts.com/images/QSTACfiltersarticle.pdf
>
> > > The difference between using it and not using it is slight, but
> > > noticeable.
>
> >http://www.radioshack.com/product/index.jsp?productId=2103222
>
> > [read reviews]
- Thanks - I have a few of those on already
- maybe I need more.
- I'd buy a batch of 100 if they were not so pricey
- and put them on everything.
BpnJ : Silencing the Electrical Path from your AC Mains
to your Radio Shack Room.
PHASE ONE : -Turn-Off-The-AC-Main-Breakers-
The Harder Work would be to Turn-Off you AC Main
Breaker to the House and Install a Ferrite Core on
the Wire {Line} coming from the Circuit Breakers that
Services your Radio Shack AC Plugs and Lights.
Note : First you have to Identify those 2~3 Circuit
Breakers in the Service Panel and the Lines {Wires}
connected to them.
PHASE TWO : -Turn-Off-The-Circuit-Breakers-
Also not easy is to find the Branch Boxes in the
http://ecmweb.com/nec/crowded_codewatchweb.jpg
House's Wiring that are in the Circuit Path from the
Service Panel to your Radio Shack.
Either in the Attic or in the Basement / Crawl-Space.
This is Dirty Work in a Hot Summer Attic
-or- Wet & Muddy in the Winter in a Crawl-Space
with an Earth Floor.
-so-dress-appropriately-as-needed-
Open-up the Branch Boxes and install the Install a
Ferrite Core on all 2~3 Wires.
* If you have new Wiring which uses the Twist-On
Wire Connectors :
https://www.hardwareworld.com/files/pi/l0/5/C443.jpg
You may be able to use something like these
Slide-On Ferrite Cores of the Right Size for your
Wires. Use 2~3 Ferrites Per Wire.
Ferrite Core 6.6mm x 9.5mm 1/4"W x 3/8"L
Round EMI Suppressor (40 LOT)
http://cgi.ebay.com/380306728593
* However if you have older House Wiring that has
Soldered Joints the Clamp-On Ferrites will do.
PHASE THREE : -Turn-Off-The-Circuit-Breakers-
The Wall Receptacles Duplex-Outlets all around
the Radio Shack Room.
Install 2~3 Slide-On Ferrite Cores on each of the
2~3 Wires connected to each Duplex-Outlet.
* Older Wiring may only have a 2-Prong Outlet
with Two Wires White and Black
* Newer Wiring may have a 3-Prong Outlet with
Two Wires White and Black and a Green or Bare
Copper/AL Wire for Ground.
http://www.electricalwire.biz/images/Romex_wire.jpg
http://www.skycraftsurplus.com/images/view.aspx?productId=828
This may have all three Wires going to the Duplex-Outlet
-or- Two Wires going to the Duplex-Outlet and the
Green or Bare Copper/AL Ground Wire going to the
Metal Box.
Either way Install 2~3 Slide-On Ferrite Cores on
the Green or Bare Copper/AL Ground Wire too.
*Next* the Ceiling Lights : Do the same Install
2~3 Slide-On Ferrite Cores on each of the 2~3
Wires in the Ceiling Light's Electrical Box.
*Then* the Wall Switches : Do the same Install
2~3 Slide-On Ferrite Cores on each of the 2~3
Wires in the Wall Switch Electrical Box.
NOTE : This is the Time when you are doing this
Work to : Clean the Bare Wire Ends and Securely
Re-Fasten {Screw} the Wires to the Duplex-Outlets;
Light Fixtures; and Wall Switches.
-cause-age-and oxidation-make-for-bad-connections-
Same Basic Three Wire Electric Cables
http://www.hardwarestore.com/pop-print/larger-image.aspx?prodNo=64511
http://www.hardwarestore.com/pop-print/larger-image.aspx?prodNo=49272
=OR= Start in the Radio Shack Room with Phase Three
and work back to Phase Two and Phase One.
dave
> hope this helps - iane ~ RHF
> .
> .
You need mix #43 for HF
bpnjensen
Not yet, but I've been thinking about a preselector. Does the MFJ
work well?
dxAce
bpnjensen wrote:
Save your money until you find out definitively whether your RFI is actually
coming in internally or externally, and if it is external, the ONLY way to
resolve that issue is trying to get something done with your local power
provider.
Elsewise... flee
dave
Yes. It's a real preselector. You have to have real 50 Ohms in. If you
use wire antennas they have an active model for about $20 more. eham
reviews may be helpful. I used my 956 for my Lowe HF-150.
dave
bpnjensen
>
> - Show quoted text -
I don't disagree - but it may be that the only way to determine
whether the problem is internal vs. external is by spending at least a
few $$. I can do this.
bpnjensen
> Question to those who may have used one - Do inline isolators work
> well on RX? Such as those sold by Radioworks?
>
> Thanks,
> Bruce Jensen
I do wish to say at this point that I greatly appreciate the interest
and information on this thread. I feel like I may be able to make some
headway, even if toward nothing else than a better understanding of
the local problems. Thanks to everyone...
BJ
John Smith
Are they current ununs or voltage ununs?
Current "baluns" should be fine ...
Regards,
JS