Best antenna (preferrably wire)
 

I have a few questions and I thought that this may be the group that could
help. I have a nice sized backyard and would like to construct an antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92 feet
from the back of the house (support exists that is about 15-20 feet up) or
120 feet from the back of the house (mast anchored to the other side of a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far end of
the property. The width of the property as seen looking out the back window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep to
the attic.

-- Cable run from back of house to operating position within the attic would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw up
the wire as winter was upon me. I have been off the air for almost 10 years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with all
of my neighbors and have visited them and did testing on the bands with them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA

On Sat, 03 Jan 2004 18:38:59 GMT, "Vaughn Combs"
wrote:

I have a few questions and I thought that this may be the group that could
help. I have a nice sized backyard and would like to construct an antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92 feet
from the back of the house (support exists that is about 15-20 feet up) or
120 feet from the back of the house (mast anchored to the other side of a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far end of
the property. The width of the property as seen looking out the back window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep to
the attic.

-- Cable run from back of house to operating position within the attic would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw up
the wire as winter was upon me. I have been off the air for almost 10 years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with all
of my neighbors and have visited them and did testing on the bands with them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA


Hi Vaughn,

Your first shot is probably your best shot. You should drop a line
from the near end antenna anchor point directly down to a ground and
rely on a tuner to make up the differences. From the anchor point
(where both wires are broke out) install a 1:1 Current Balun (Choke)
between these points and the transmission line back to your rig to
eliminate some of your noise into the house, and to get rid of the 40M
instability (a classic symptom of Common Mode whose cure is in the
Choke). The "ground" lead will radiate, but that is inconsequential.
You may also experience a ground loop with it in parallel to your
rig's source of ground.

This is the blind-side of many hams who forget that long ground wires
have impedance and thus become miserable grounds for RF. Unless you
work battery operation without a floating charger, you WILL have this
second path to ground (the 'trons will find their own way, even if it
isn't obvious to you). I always run battery with a float charger
through an 1:1 isolation transformer to kill Mains borne noise; and
whenever I experience ground loops, I simply disconnect the charger.

73's
Richard Clark, KB7QHC

On Sat, 03 Jan 2004 18:38:59 GMT, "Vaughn Combs"
wrote:

I have a few questions and I thought that this may be the group that could
help. I have a nice sized backyard and would like to construct an antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92 feet
from the back of the house (support exists that is about 15-20 feet up) or
120 feet from the back of the house (mast anchored to the other side of a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far end of
the property. The width of the property as seen looking out the back window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep to
the attic.

-- Cable run from back of house to operating position within the attic would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw up
the wire as winter was upon me. I have been off the air for almost 10 years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with all
of my neighbors and have visited them and did testing on the bands with them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA


Hi Vaughn,

Your first shot is probably your best shot. You should drop a line
from the near end antenna anchor point directly down to a ground and
rely on a tuner to make up the differences. From the anchor point
(where both wires are broke out) install a 1:1 Current Balun (Choke)
between these points and the transmission line back to your rig to
eliminate some of your noise into the house, and to get rid of the 40M
instability (a classic symptom of Common Mode whose cure is in the
Choke). The "ground" lead will radiate, but that is inconsequential.
You may also experience a ground loop with it in parallel to your
rig's source of ground.

This is the blind-side of many hams who forget that long ground wires
have impedance and thus become miserable grounds for RF. Unless you
work battery operation without a floating charger, you WILL have this
second path to ground (the 'trons will find their own way, even if it
isn't obvious to you). I always run battery with a float charger
through an 1:1 isolation transformer to kill Mains borne noise; and
whenever I experience ground loops, I simply disconnect the charger.

73's
Richard Clark, KB7QHC

Vaughn Combs wrote:
Any ideas would be GREATLY appreciated.

To effectively avoid RF in the shack, the differential currents need
to be balanced (equal in magnitude and 180 degrees out of phase). It
is extremely difficult to do that with an inv-L. I had good luck with
a dipole even though the shack was under one end of the dipole. I
brought the ladder-line off at right angles for about 50 ft then
routed ladder-line back to the shack from there so ladder-line
parallel to the antenna was always about 50 ft away from the antenna.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Vaughn Combs wrote:
Any ideas would be GREATLY appreciated.

To effectively avoid RF in the shack, the differential currents need
to be balanced (equal in magnitude and 180 degrees out of phase). It
is extremely difficult to do that with an inv-L. I had good luck with
a dipole even though the shack was under one end of the dipole. I
brought the ladder-line off at right angles for about 50 ft then
routed ladder-line back to the shack from there so ladder-line
parallel to the antenna was always about 50 ft away from the antenna.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Hi Richard,

If this helps both my XYL and I will be in your debt ;-)

So I should solder a shielded copper wire to the near end (aka the feed
point but on the other side of the insulator --- near the house), let it run
down the side of the house (about 22 to 25 feet down) and then to a ground
rod? Then connect both the wire from the point where the new ground wire
attaches and the wire (formerly the feedline) that connects to the "long"
wire to the balun. Then its on into the house and the tuner via RG-8.
Correct?

What do I connect to the ground lugs on the tuner and rig? The inefficient
RF ground wire that I have now? That wire currently goes to a ground strip
that has 1/4 wave length radials that were cut for each band running through
the attic and an additional wire that is attached to a pipe that I found in
the attic that is a plumbing drain pipe vent.

BTW, would there be any advantage to using other than 1:1 for the current
balun? Any recommendations for the balun? I have seen some that can be made
simply from coax.

I hope that I am not being a pain but this RFI prob is a bugger and it would
be REALLY nice to squash this one. It is bugging the XYL quite a bit and it
limits my operating time ;-)

Also, the ground loop that you are referring to would be current in the
shield (or in my case the outer skin of the copper wire ;-) coming through
the feed line and into the equipment. From there it is possibly getting into
electrical ground through the power supply?

Again, Many thanks for your help and 73,

Vaughn, N2BHA



"Richard Clark" wrote in message
...
On Sat, 03 Jan 2004 18:38:59 GMT, "Vaughn Combs"
wrote:

I have a few questions and I thought that this may be the group that
could
help. I have a nice sized backyard and would like to construct an antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92 feet
from the back of the house (support exists that is about 15-20 feet up)
or
120 feet from the back of the house (mast anchored to the other side of a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far end
of
the property. The width of the property as seen looking out the back
window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep
to
the attic.

-- Cable run from back of house to operating position within the attic
would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands
except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw
up
the wire as winter was upon me. I have been off the air for almost 10
years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I
am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have
cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with
all
of my neighbors and have visited them and did testing on the bands with
them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned
RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA


Hi Vaughn,

Your first shot is probably your best shot. You should drop a line
from the near end antenna anchor point directly down to a ground and
rely on a tuner to make up the differences. From the anchor point
(where both wires are broke out) install a 1:1 Current Balun (Choke)
between these points and the transmission line back to your rig to
eliminate some of your noise into the house, and to get rid of the 40M
instability (a classic symptom of Common Mode whose cure is in the
Choke). The "ground" lead will radiate, but that is inconsequential.
You may also experience a ground loop with it in parallel to your
rig's source of ground.

This is the blind-side of many hams who forget that long ground wires
have impedance and thus become miserable grounds for RF. Unless you
work battery operation without a floating charger, you WILL have this
second path to ground (the 'trons will find their own way, even if it
isn't obvious to you). I always run battery with a float charger
through an 1:1 isolation transformer to kill Mains borne noise; and
whenever I experience ground loops, I simply disconnect the charger.

73's
Richard Clark, KB7QHC

Hi Richard,

If this helps both my XYL and I will be in your debt ;-)

So I should solder a shielded copper wire to the near end (aka the feed
point but on the other side of the insulator --- near the house), let it run
down the side of the house (about 22 to 25 feet down) and then to a ground
rod? Then connect both the wire from the point where the new ground wire
attaches and the wire (formerly the feedline) that connects to the "long"
wire to the balun. Then its on into the house and the tuner via RG-8.
Correct?

What do I connect to the ground lugs on the tuner and rig? The inefficient
RF ground wire that I have now? That wire currently goes to a ground strip
that has 1/4 wave length radials that were cut for each band running through
the attic and an additional wire that is attached to a pipe that I found in
the attic that is a plumbing drain pipe vent.

BTW, would there be any advantage to using other than 1:1 for the current
balun? Any recommendations for the balun? I have seen some that can be made
simply from coax.

I hope that I am not being a pain but this RFI prob is a bugger and it would
be REALLY nice to squash this one. It is bugging the XYL quite a bit and it
limits my operating time ;-)

Also, the ground loop that you are referring to would be current in the
shield (or in my case the outer skin of the copper wire ;-) coming through
the feed line and into the equipment. From there it is possibly getting into
electrical ground through the power supply?

Again, Many thanks for your help and 73,

Vaughn, N2BHA



"Richard Clark" wrote in message
...
On Sat, 03 Jan 2004 18:38:59 GMT, "Vaughn Combs"
wrote:

I have a few questions and I thought that this may be the group that
could
help. I have a nice sized backyard and would like to construct an antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92 feet
from the back of the house (support exists that is about 15-20 feet up)
or
120 feet from the back of the house (mast anchored to the other side of a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far end
of
the property. The width of the property as seen looking out the back
window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep
to
the attic.

-- Cable run from back of house to operating position within the attic
would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands
except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw
up
the wire as winter was upon me. I have been off the air for almost 10
years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I
am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have
cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with
all
of my neighbors and have visited them and did testing on the bands with
them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned
RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA


Hi Vaughn,

Your first shot is probably your best shot. You should drop a line
from the near end antenna anchor point directly down to a ground and
rely on a tuner to make up the differences. From the anchor point
(where both wires are broke out) install a 1:1 Current Balun (Choke)
between these points and the transmission line back to your rig to
eliminate some of your noise into the house, and to get rid of the 40M
instability (a classic symptom of Common Mode whose cure is in the
Choke). The "ground" lead will radiate, but that is inconsequential.
You may also experience a ground loop with it in parallel to your
rig's source of ground.

This is the blind-side of many hams who forget that long ground wires
have impedance and thus become miserable grounds for RF. Unless you
work battery operation without a floating charger, you WILL have this
second path to ground (the 'trons will find their own way, even if it
isn't obvious to you). I always run battery with a float charger
through an 1:1 isolation transformer to kill Mains borne noise; and
whenever I experience ground loops, I simply disconnect the charger.

73's
Richard Clark, KB7QHC

On Sat, 03 Jan 2004 22:11:39 GMT, "Vaughn Combs"
wrote:

Hi Richard,

If this helps both my XYL and I will be in your debt ;-)

It comes with the usual expectation of your first born....

So I should solder a shielded copper wire to the near end (aka the feed
point but on the other side of the insulator --- near the house), let it run
down the side of the house (about 22 to 25 feet down) and then to a ground
rod? Then connect both the wire from the point where the new ground wire
attaches and the wire (formerly the feedline) that connects to the "long"
wire to the balun. Then its on into the house and the tuner via RG-8.
Correct?

Yup. That is what I was describing, but it could work dangling (with
a sealed, insulated end that is mechanically tied down; however, this
is not anymore efficient as the floating wires along your rafters,
merely different).

View with fixed font:
BalUn longwire
rig --- tuner ant ---OOOOO-----------------------------
rig --- tuner gnd ---OOOOO-+
| |
| | drop
| |
----- -----
--- ---
- -

Ground loop issues arise due to there being two paths with a
significant distance (in wavelength) between them (from the +
down, through ground, and back up to the rig) and an impedance between
(the BalUn which serves this purpose by design). This usually comes
about when the ham shack is elevated, and still has some form of
ground return that is an appreciable distance (in wavelength,
basically more than 0.1 wavelength) from true ground.

The rig ground may be deliberate, or it may be passive through metal
connections and continuity with the power supply which in turn
inherits it from the wall socket. Even if there is no safety ground
from the wall socket, there is still a capacitive coupling in the
wiring to fulfill the mission (and 40/80M probably plays hell with the
VCR).

What do I connect to the ground lugs on the tuner and rig? The inefficient
RF ground wire that I have now? That wire currently goes to a ground strip
that has 1/4 wave length radials that were cut for each band running through
the attic and an additional wire that is attached to a pipe that I found in
the attic that is a plumbing drain pipe vent.

This may still be a viable option. Don't discard anything, simply
isolate one or all and experiment (it's the name of the game).


BTW, would there be any advantage to using other than 1:1 for the current
balun? Any recommendations for the balun? I have seen some that can be made
simply from coax.

Simple coax chokes work just as effectively. Half a dozen to eight
turns of six to eight inch turns will be adequate for 40-15M, you may
need to experiment with a few more turns outside of this. Current
BalUns are simply Ferrite donuts put over a 1 foot length of RG-52
coax (one or a couple dozen donuts). The same thing can be achieved
with a large torus with four or five turns of coax through the center
(if its big enough). This is square law time, so four turns equals 16
donuts. Stacking two large toroids with 3 turns each would substitute
(or maybe three with three turns).

Using ferrite makes for a smaller device that works over a larger span
of frequencies, but winding air wounds can be tested immediately at no
more cost than the cable already handy.

I hope that I am not being a pain but this RFI prob is a bugger and it would
be REALLY nice to squash this one. It is bugging the XYL quite a bit and it
limits my operating time ;-)

Also, the ground loop that you are referring to would be current in the
shield (or in my case the outer skin of the copper wire ;-) coming through
the feed line and into the equipment. From there it is possibly getting into
electrical ground through the power supply?

Again, Many thanks for your help and 73,

Vaughn, N2BHA

Hi Vaughn,

I've described the ground loop above. Isolating it means "busting"
ground somewhere. I use a battery. Voila! Opening any path does
just as well, but you have a dangling radiator somewhere (like the
drop). This may help, or it may change nothing. RFI problems are
unique to every situation and having your shack up high is the major
contributor, but to keep peace in the family try to limit RF exposure
to the end of the pipe (the purpose of the choke).

The choke inhibits RF from traveling back (conduction) into your shack
(but your rafter mounted "radials" contribute RF exposure through
radiation). You might try wrapping your power supply AC leads through
a ferrite (or use a split core). This is choking your rig from going
into the House AC. If you do this, take care to observe ALL
connections to the rig. Do you have a packet connection to the rig
from a computer? This is another path to ground, Choke it!!! Do you
have a modem on the computer? Ditto. Computer Display? Ditto. A
powered microphone? Ditto. The shack is a hydra of wires all heading
to ground eventually and all it takes is one - and sometimes it melts.

There are three forms of power transfer: Conduction, Radiation, and
Convection. Clearly convection is out as we are not heating soup.
Conduction comes through wire, and radiation through the air. Your
problems (as for most) usually comes by virtue of shared paths in the
AC distribution and this is a conduction issue. If you move your
rig's power supply to another wall socket ON A DIFFERENT BREAKER, you
might solve one problem (and discover a new one). Use an extension
cord (choke it) to experiment with this possibility. Having the
antenna feed point close to the house brings about the possibility of
radiation coupling. Move it (the choke point) away from the house.
Remember this is square law time too and with each doubling, you
quarter your exposure.

73's
Richard Clark, KB7QHC

On Sat, 03 Jan 2004 22:11:39 GMT, "Vaughn Combs"
wrote:

Hi Richard,

If this helps both my XYL and I will be in your debt ;-)

It comes with the usual expectation of your first born....

So I should solder a shielded copper wire to the near end (aka the feed
point but on the other side of the insulator --- near the house), let it run
down the side of the house (about 22 to 25 feet down) and then to a ground
rod? Then connect both the wire from the point where the new ground wire
attaches and the wire (formerly the feedline) that connects to the "long"
wire to the balun. Then its on into the house and the tuner via RG-8.
Correct?

Yup. That is what I was describing, but it could work dangling (with
a sealed, insulated end that is mechanically tied down; however, this
is not anymore efficient as the floating wires along your rafters,
merely different).

View with fixed font:
BalUn longwire
rig --- tuner ant ---OOOOO-----------------------------
rig --- tuner gnd ---OOOOO-+
| |
| | drop
| |
----- -----
--- ---
- -

Ground loop issues arise due to there being two paths with a
significant distance (in wavelength) between them (from the +
down, through ground, and back up to the rig) and an impedance between
(the BalUn which serves this purpose by design). This usually comes
about when the ham shack is elevated, and still has some form of
ground return that is an appreciable distance (in wavelength,
basically more than 0.1 wavelength) from true ground.

The rig ground may be deliberate, or it may be passive through metal
connections and continuity with the power supply which in turn
inherits it from the wall socket. Even if there is no safety ground
from the wall socket, there is still a capacitive coupling in the
wiring to fulfill the mission (and 40/80M probably plays hell with the
VCR).

What do I connect to the ground lugs on the tuner and rig? The inefficient
RF ground wire that I have now? That wire currently goes to a ground strip
that has 1/4 wave length radials that were cut for each band running through
the attic and an additional wire that is attached to a pipe that I found in
the attic that is a plumbing drain pipe vent.

This may still be a viable option. Don't discard anything, simply
isolate one or all and experiment (it's the name of the game).


BTW, would there be any advantage to using other than 1:1 for the current
balun? Any recommendations for the balun? I have seen some that can be made
simply from coax.

Simple coax chokes work just as effectively. Half a dozen to eight
turns of six to eight inch turns will be adequate for 40-15M, you may
need to experiment with a few more turns outside of this. Current
BalUns are simply Ferrite donuts put over a 1 foot length of RG-52
coax (one or a couple dozen donuts). The same thing can be achieved
with a large torus with four or five turns of coax through the center
(if its big enough). This is square law time, so four turns equals 16
donuts. Stacking two large toroids with 3 turns each would substitute
(or maybe three with three turns).

Using ferrite makes for a smaller device that works over a larger span
of frequencies, but winding air wounds can be tested immediately at no
more cost than the cable already handy.

I hope that I am not being a pain but this RFI prob is a bugger and it would
be REALLY nice to squash this one. It is bugging the XYL quite a bit and it
limits my operating time ;-)

Also, the ground loop that you are referring to would be current in the
shield (or in my case the outer skin of the copper wire ;-) coming through
the feed line and into the equipment. From there it is possibly getting into
electrical ground through the power supply?

Again, Many thanks for your help and 73,

Vaughn, N2BHA

Hi Vaughn,

I've described the ground loop above. Isolating it means "busting"
ground somewhere. I use a battery. Voila! Opening any path does
just as well, but you have a dangling radiator somewhere (like the
drop). This may help, or it may change nothing. RFI problems are
unique to every situation and having your shack up high is the major
contributor, but to keep peace in the family try to limit RF exposure
to the end of the pipe (the purpose of the choke).

The choke inhibits RF from traveling back (conduction) into your shack
(but your rafter mounted "radials" contribute RF exposure through
radiation). You might try wrapping your power supply AC leads through
a ferrite (or use a split core). This is choking your rig from going
into the House AC. If you do this, take care to observe ALL
connections to the rig. Do you have a packet connection to the rig
from a computer? This is another path to ground, Choke it!!! Do you
have a modem on the computer? Ditto. Computer Display? Ditto. A
powered microphone? Ditto. The shack is a hydra of wires all heading
to ground eventually and all it takes is one - and sometimes it melts.

There are three forms of power transfer: Conduction, Radiation, and
Convection. Clearly convection is out as we are not heating soup.
Conduction comes through wire, and radiation through the air. Your
problems (as for most) usually comes by virtue of shared paths in the
AC distribution and this is a conduction issue. If you move your
rig's power supply to another wall socket ON A DIFFERENT BREAKER, you
might solve one problem (and discover a new one). Use an extension
cord (choke it) to experiment with this possibility. Having the
antenna feed point close to the house brings about the possibility of
radiation coupling. Move it (the choke point) away from the house.
Remember this is square law time too and with each doubling, you
quarter your exposure.

73's
Richard Clark, KB7QHC

hi there..

think i will put my pennys worth in here...

do away with the long wire altogether..you will proberly never get rid of
the rf in shack etc..due to being too high above gnd..i know i have tried..i
live in an apartment (3rd floor)..no garden or land..i have tried end feed
long wire from balcony to lamp post etc..rfi to phones stereo etc..BAD

i tried all the tricks in the book no go...
SO.. i chatted my neighboors up and have been using successfully for 4 years
now a full sized 10m-80m diople (trapped with 40m trapps.)its slung up at 3
points in the shape of a triangle each courner on someone elses
apartment..the coax feed is rolled up 6 times 6inches dia just before diople
feed point..i have hung seperate dioples for 18mhz.28mz below main diople to
help on those bands ..
i have had NO tvi/stereo i/ phone i etc atall (touch wood)..i am using full
size diople but not out straight so you could too, espically as you have a
garden!!!
and have worked much dx all over the world with 100w ssb...

so if you give up with the long wire (as i did) try this..its cheap too..and
the antenna is in about every antenna handbook..)

simon g0zen
"Cecil Moore" wrote in message
...
Vaughn Combs wrote:
Any ideas would be GREATLY appreciated.

To effectively avoid RF in the shack, the differential currents need
to be balanced (equal in magnitude and 180 degrees out of phase). It
is extremely difficult to do that with an inv-L. I had good luck with
a dipole even though the shack was under one end of the dipole. I
brought the ladder-line off at right angles for about 50 ft then
routed ladder-line back to the shack from there so ladder-line
parallel to the antenna was always about 50 ft away from the antenna.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

hi there..

think i will put my pennys worth in here...

do away with the long wire altogether..you will proberly never get rid of
the rf in shack etc..due to being too high above gnd..i know i have tried..i
live in an apartment (3rd floor)..no garden or land..i have tried end feed
long wire from balcony to lamp post etc..rfi to phones stereo etc..BAD

i tried all the tricks in the book no go...
SO.. i chatted my neighboors up and have been using successfully for 4 years
now a full sized 10m-80m diople (trapped with 40m trapps.)its slung up at 3
points in the shape of a triangle each courner on someone elses
apartment..the coax feed is rolled up 6 times 6inches dia just before diople
feed point..i have hung seperate dioples for 18mhz.28mz below main diople to
help on those bands ..
i have had NO tvi/stereo i/ phone i etc atall (touch wood)..i am using full
size diople but not out straight so you could too, espically as you have a
garden!!!
and have worked much dx all over the world with 100w ssb...

so if you give up with the long wire (as i did) try this..its cheap too..and
the antenna is in about every antenna handbook..)

simon g0zen
"Cecil Moore" wrote in message
...
Vaughn Combs wrote:
Any ideas would be GREATLY appreciated.

To effectively avoid RF in the shack, the differential currents need
to be balanced (equal in magnitude and 180 degrees out of phase). It
is extremely difficult to do that with an inv-L. I had good luck with
a dipole even though the shack was under one end of the dipole. I
brought the ladder-line off at right angles for about 50 ft then
routed ladder-line back to the shack from there so ladder-line
parallel to the antenna was always about 50 ft away from the antenna.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Always begin with the most simple of antennas. Otherwise you'll have
nothing to make comparisons with. You will have no base or foundation
standard.

Spend a couple of hours stringing up a 150 feet inverted-L and use it on all
bands for a few weeks. That is if you can wrench youself away from it.
----
Reg, G4FGQ

Always begin with the most simple of antennas. Otherwise you'll have
nothing to make comparisons with. You will have no base or foundation
standard.

Spend a couple of hours stringing up a 150 feet inverted-L and use it on all
bands for a few weeks. That is if you can wrench youself away from it.
----
Reg, G4FGQ

Vaughn,

It's quite easy: your best bet is the maximum length of wire you can keep
in your backyard AND as high up in the air as you can afford (trees,
towers, chimneys etc.)

To prevent RFI and TVI, make your antenna symmetrical. Feed it with an
open line, and connect the open line with your TX with an appropriate
coupler (the ARRL Handbook is a good source for information).

Please note you do not need to use a thick gauge of copper wire. Even a
thin gauge of stainless steel wire will do.

You will be pleased very much by the results !!

73 de PA0ARY

On Sat, 03 Jan 2004 18:38:59 +0000, Vaughn Combs wrote:

I have a few questions and I thought that this may be the group that could
help. I have a nice sized backyard and would like to construct an antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92 feet
from the back of the house (support exists that is about 15-20 feet up) or
120 feet from the back of the house (mast anchored to the other side of a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far end of
the property. The width of the property as seen looking out the back window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep to
the attic.

-- Cable run from back of house to operating position within the attic would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw up
the wire as winter was upon me. I have been off the air for almost 10 years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with all
of my neighbors and have visited them and did testing on the bands with them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA

ary wrote:
It's quite easy: your best bet is the maximum length of wire you can keep
in your backyard AND as high up in the air as you can afford (trees,
towers, chimneys etc.)

Hmmmmm, my back yard is ten acres. :-)
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

"ary" wrote in message
.. .
Vaughn,

It's quite easy: your best bet is the maximum length of wire you can keep
in your backyard AND as high up in the air as you can afford (trees,
towers, chimneys etc.)

To prevent RFI and TVI, make your antenna symmetrical. Feed it with an
open line, and connect the open line with your TX with an appropriate
coupler (the ARRL Handbook is a good source for information).

Hi,

All depends. I already underligned 2 big mistakes about SWR and ground
screen.
All is relative you know


Please note you do not need to use a thick gauge of copper wire. Even a
thin gauge of stainless steel wire will do.

I call this a G5RV... ;-)

Thierry
ON4SKY
http://www.astrosurf.com/lombry/qsl-g5rv.htm


You will be pleased very much by the results !!

73 de PA0ARY

On Sat, 03 Jan 2004 18:38:59 +0000, Vaughn Combs wrote:

I have a few questions and I thought that this may be the group that
could
help. I have a nice sized backyard and would like to construct an
antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92
feet
from the back of the house (support exists that is about 15-20 feet up)
or
120 feet from the back of the house (mast anchored to the other side of
a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far
end of
the property. The width of the property as seen looking out the back
window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep
to
the attic.

-- Cable run from back of house to operating position within the attic
would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands
except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw
up
the wire as winter was upon me. I have been off the air for almost 10
years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I
am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have
cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with
all
of my neighbors and have visited them and did testing on the bands with
them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned
RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA

It's quite easy: your best bet is the maximum length of wire you can keep
in your backyard AND as high up in the air as you can afford (trees,
towers, chimneys etc.)

Hmmmmm, my back yard is ten acres. :-)

Until wind toppled the tree at one end, my "dipole" went 275 feet SW
and 250 feet NE of the "center" feed point. Height was about 45 feet.

Someone once commented that the reason I "got out" so well was that,
by the time the RF reached the end of my antenna, it was already a
significant part of the distance toward its destination!-)

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

The best antenna is not the longest thing you can put up, unless one of the
many minor lobes you create will point exactly where you want to go at a
radiation angle you need, and this is highly unlikely, but it does sometimes
happen.

The best thing to do is decide where you'd like to reach, for example, which
continent. Are you a DXer or do you do mostly local rag chews? What
frequency bands would you like to operate, and what size constraints do you
have to live with? Are there any natural supports you'd like to take
advantage of? Do you need multiband operation? Do you have an deed
restrictions on what you can put up?

Study the radiation patterns of dipoles, verticals and if you have the
space, long wires.

Do you have a tuner?

Remember, no antenna creates RF to get "gain", they only focus it. The
ideal RF antenna would radiate equally well in all directions. Since you
live on earth, the effect of height is an issue, as is the ground effect on
the pattern.

The best antenna to start with for a newbie is a windom cut for the lowest
band that will fit on your lot. With this kind of antenna you can run all
harmonic bands (ie 80M will cover 40M,20M,10M while 40M will cover 40M, 20M,
10M) quite well and not require a tuner. Several of the WARC bands will
work ok too but the SWR may be a little higher. I regularly use my 80M
windom on all bands here, most of them without a tuner, and the rigs tuner
is good enough on the one or two where the SWR is just over 2:1 which isn't
an issue, it just causes the radio to reduce power.

The second best antenna is a vertical, but most newbies screw up the
installation. You either need 4 elevated radials or you need lots of
radials on the ground. Lots means 16 or more. Again, the literature is
full of information on these topics, and there was even an article a few
months ago in QST I think where someone did a study on the best use of the
wire for a vertical ground plan - ie more or longer radials for a given
length of wire to optimize results.

The vertical is a good newbie antenna because it radiates equally well (some
say equally poorly) in all directions. Although some of that will go to
places where no one lives, if you have a good ground plane the low angle of
radiation will be to your advantage. One caution, if you live with a lot of
neighbors around verticals pick up noise more than horizontal antennas and
this can be a big issue. In that case stick with a windom.

If you have the money and the time and a computer, try purchasing an antenna
modeling software packet. I use NEC4WIN but there are many. With this, you
can model various wire configurations quickly and see EXACTLY what they will
do in terms of gain/loss/pattern etc. This will save you a lot of time and
money building things that don't work.

Finally, if your interest is local ragchewing, a low horizontal antenna may
be just fine.

I have an extensive antenna farm here, quads, yagis, dipoles, verticals,
etc. and over the past 35 years I've tried everything. The best overall
antenna, the one that I keep coming back to as a standard or default for
comparison is the windom. This off center fed device is fed at a point
where the SWR is tolerable on harmonically related bands using a matching
balun. My favorite was made by Fritzel, but I don't think they make them
anymore, but an internet search will turn up several suppliers and/or plans
for your own. The biggest issue in a windom is just the balun, and I
recommend CWS Bytemark products if you can get them.

Again though, remember that once the lengh of the wire is greater than 1/2
wavelengh the pattern starts to form lobes that can give you a great
signal - somewhere - and an equally poor signal in other places. This is
true for a windom too, on its harmonic bands. That is why 40 meter windoms
exist (besides the fact that they are shorter).

One of the best ways to solve your problem is by reading. Fortunately these
days you can read about antennas for hours on the internet at no cost, but
the best books I've found over the years are the ARRL Anthology series and
of course the ARRL antenna book.

73,
WT6G
PS Do not waste your time and reply to this email address. It won't work.




"ary" wrote in message
.. .
Vaughn,

It's quite easy: your best bet is the maximum length of wire you can keep
in your backyard AND as high up in the air as you can afford (trees,
towers, chimneys etc.)

To prevent RFI and TVI, make your antenna symmetrical. Feed it with an
open line, and connect the open line with your TX with an appropriate
coupler (the ARRL Handbook is a good source for information).

Please note you do not need to use a thick gauge of copper wire. Even a
thin gauge of stainless steel wire will do.

You will be pleased very much by the results !!

73 de PA0ARY

On Sat, 03 Jan 2004 18:38:59 +0000, Vaughn Combs wrote:

I have a few questions and I thought that this may be the group that
could
help. I have a nice sized backyard and would like to construct an
antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92
feet
from the back of the house (support exists that is about 15-20 feet up)
or
120 feet from the back of the house (mast anchored to the other side of
a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far
end of
the property. The width of the property as seen looking out the back
window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep
to
the attic.

-- Cable run from back of house to operating position within the attic
would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands
except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw
up
the wire as winter was upon me. I have been off the air for almost 10
years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I
am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have
cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with
all
of my neighbors and have visited them and did testing on the bands with
them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned
RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA





-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

The best antenna is not the longest thing you can put up, unless one of the
many minor lobes you create will point exactly where you want to go at a
radiation angle you need, and this is highly unlikely, but it does sometimes
happen.

The best thing to do is decide where you'd like to reach, for example, which
continent. Are you a DXer or do you do mostly local rag chews? What
frequency bands would you like to operate, and what size constraints do you
have to live with? Are there any natural supports you'd like to take
advantage of? Do you need multiband operation? Do you have an deed
restrictions on what you can put up?

Study the radiation patterns of dipoles, verticals and if you have the
space, long wires.

Do you have a tuner?

Remember, no antenna creates RF to get "gain", they only focus it. The
ideal RF antenna would radiate equally well in all directions. Since you
live on earth, the effect of height is an issue, as is the ground effect on
the pattern.

The best antenna to start with for a newbie is a windom cut for the lowest
band that will fit on your lot. With this kind of antenna you can run all
harmonic bands (ie 80M will cover 40M,20M,10M while 40M will cover 40M, 20M,
10M) quite well and not require a tuner. Several of the WARC bands will
work ok too but the SWR may be a little higher. I regularly use my 80M
windom on all bands here, most of them without a tuner, and the rigs tuner
is good enough on the one or two where the SWR is just over 2:1 which isn't
an issue, it just causes the radio to reduce power.

The second best antenna is a vertical, but most newbies screw up the
installation. You either need 4 elevated radials or you need lots of
radials on the ground. Lots means 16 or more. Again, the literature is
full of information on these topics, and there was even an article a few
months ago in QST I think where someone did a study on the best use of the
wire for a vertical ground plan - ie more or longer radials for a given
length of wire to optimize results.

The vertical is a good newbie antenna because it radiates equally well (some
say equally poorly) in all directions. Although some of that will go to
places where no one lives, if you have a good ground plane the low angle of
radiation will be to your advantage. One caution, if you live with a lot of
neighbors around verticals pick up noise more than horizontal antennas and
this can be a big issue. In that case stick with a windom.

If you have the money and the time and a computer, try purchasing an antenna
modeling software packet. I use NEC4WIN but there are many. With this, you
can model various wire configurations quickly and see EXACTLY what they will
do in terms of gain/loss/pattern etc. This will save you a lot of time and
money building things that don't work.

Finally, if your interest is local ragchewing, a low horizontal antenna may
be just fine.

I have an extensive antenna farm here, quads, yagis, dipoles, verticals,
etc. and over the past 35 years I've tried everything. The best overall
antenna, the one that I keep coming back to as a standard or default for
comparison is the windom. This off center fed device is fed at a point
where the SWR is tolerable on harmonically related bands using a matching
balun. My favorite was made by Fritzel, but I don't think they make them
anymore, but an internet search will turn up several suppliers and/or plans
for your own. The biggest issue in a windom is just the balun, and I
recommend CWS Bytemark products if you can get them.

Again though, remember that once the lengh of the wire is greater than 1/2
wavelengh the pattern starts to form lobes that can give you a great
signal - somewhere - and an equally poor signal in other places. This is
true for a windom too, on its harmonic bands. That is why 40 meter windoms
exist (besides the fact that they are shorter).

One of the best ways to solve your problem is by reading. Fortunately these
days you can read about antennas for hours on the internet at no cost, but
the best books I've found over the years are the ARRL Anthology series and
of course the ARRL antenna book.

73,
WT6G
PS Do not waste your time and reply to this email address. It won't work.




"ary" wrote in message
.. .
Vaughn,

It's quite easy: your best bet is the maximum length of wire you can keep
in your backyard AND as high up in the air as you can afford (trees,
towers, chimneys etc.)

To prevent RFI and TVI, make your antenna symmetrical. Feed it with an
open line, and connect the open line with your TX with an appropriate
coupler (the ARRL Handbook is a good source for information).

Please note you do not need to use a thick gauge of copper wire. Even a
thin gauge of stainless steel wire will do.

You will be pleased very much by the results !!

73 de PA0ARY

On Sat, 03 Jan 2004 18:38:59 +0000, Vaughn Combs wrote:

I have a few questions and I thought that this may be the group that
could
help. I have a nice sized backyard and would like to construct an
antenna
that would give me good performance on 80-10m bands.

The convenient dimensions would put a support (far end) at either 92
feet
from the back of the house (support exists that is about 15-20 feet up)
or
120 feet from the back of the house (mast anchored to the other side of
a
shed could easily be installed. Or a more inconvenient support could be
erected up to 300 feet out (no support buildings) at the absolute far
end of
the property. The width of the property as seen looking out the back
window
is about 65 feet (no supports existing on either side).

Special circumstances and constraints:

-- No tall trees on the property.

-- Attic shack (attic window is probably about 25 feet up). Need to keep
to
the attic.

-- Cable run from back of house to operating position within the attic
would
be approximately 25 feet

-- MUST eliminate RFI in the shack and house.

My current setup is an end-fed longwire that works well on all bands
except
40m (rig shuts down as I am dipping the SWR to almost 1:1 ;-). I threw
up
the wire as winter was upon me. I have been off the air for almost 10
years
and REALLY wanted to get on the air again.

While the longwire is performing quite well with the exception of 40m I
am
getting a ton of RF in the shack and it is blanking out TVs and creating
loud humming in speakers with 100W from the XMTR. I realize that this is
most likely due to the fact that I have inefficient RF ground and I have
cut
and run radial at 1/4 wave for each band and ran them under the eaves up
here in the attic. This has not solved the problem. I am friendly with
all
of my neighbors and have visited them and did testing on the bands with
them
on the phone. They are not experiencing any problems. My wife, while
understanding, would REALLY like the problem to go away ;-)

My main goal is to build an antenna that will solve the aforementioned
RFI
problem and that will provide good performance given my constraints.

Any ideas would be GREATLY appreciated.

Many Thanks and 73,
Vaughn
N2BHA





-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----