On 3-Aug-2009, Brad wrote:

Is this intended as an RF ground or lightning protection?

Primarily an RF ground since the antennas will be in my attic. However, I would appreciate the
information for both cases.

"KJ4NTS" wrote in message
...

On 3-Aug-2009, Brad wrote:

Is this intended as an RF ground or lightning protection?

Primarily an RF ground since the antennas will be in my attic. However, I
would appreciate the
information for both cases.

I think code calls for #6 solid Copper or Aluminum for lightning protection.
Consider the 50 ft as part of the antenna though. Rather than even trying
to have an RF "ground" try to make a counterpoise instead. Read up on the
difference between RF ground, lightning ground, and electrical ground. You
don't say what kind of antenna.

On Aug 3, 10:01*am, "JB" wrote:
"KJ4NTS" wrote in message

...

On *3-Aug-2009, Brad wrote:

Is this intended as an RF ground or lightning protection?

Primarily an RF ground since the antennas will be in my attic. *However, I

would appreciate the

information for both cases.

I think code calls for #6 solid Copper or Aluminum for lightning protection.
Consider the 50 ft as part of the antenna though. *Rather than even trying
to have an RF "ground" try to make a counterpoise instead. *Read up on the
difference between RF ground, lightning ground, and electrical ground. *You
don't say what kind of antenna.

Interesting question.
The poster is in an attic which suggests he will need a very long wire
to get to a "ground." Presumably the chassis of his radio is
connected to a "ground" at a service pole via the power plug.
The antenna I assume is floating above "ground" via a inter connecting
capacitor of a low breakdown voltage to the chassis. So one has to ask
what an added "ground" wire is going to do for you and what
disadvantages with respect to protections it is it putting in place?

On 3-Aug-2009, "JB" wrote:

Primarily an RF ground since the antennas will be in my attic. However, I
would appreciate the
information for both cases.

I think code calls for #6 solid Copper or Aluminum for lightning protection.
Consider the 50 ft as part of the antenna though. Rather than even trying
to have an RF "ground" try to make a counterpoise instead. Read up on the
difference between RF ground, lightning ground, and electrical ground. You
don't say what kind of antenna.

I could put a surface wire counterpoise in the crawl space under my office where the radio is
located. If I did that, there would be only about a 5 or 6 foot run to the center point of the
counterpoise.

Assuming the counterpoise wires are laying on the dirt floor of the crawl space, how many wires
would I need, and how long do they need to be. I want to be able to work 6 through 40 meters.

If I install a wire counterpoise like this, is there any problem also connecting the earth ground
connection to the central ground bar in my office?

The attic antenna is an Alpha Delta DX-EE.

"KJ4NTS" wrote in message
...

On 3-Aug-2009, "JB" wrote:

Primarily an RF ground since the antennas will be in my attic.
However, I
would appreciate the
information for both cases.

I think code calls for #6 solid Copper or Aluminum for lightning
protection.
Consider the 50 ft as part of the antenna though. Rather than even
trying
to have an RF "ground" try to make a counterpoise instead. Read up on
the
difference between RF ground, lightning ground, and electrical ground.
You
don't say what kind of antenna.

I could put a surface wire counterpoise in the crawl space under my office
where the radio is
located. If I did that, there would be only about a 5 or 6 foot run to
the center point of the
counterpoise.

Assuming the counterpoise wires are laying on the dirt floor of the crawl
space, how many wires
would I need, and how long do they need to be. I want to be able to work
6 through 40 meters.

If I install a wire counterpoise like this, is there any problem also
connecting the earth ground
connection to the central ground bar in my office?

The attic antenna is an Alpha Delta DX-EE.

This is a balanced antenna and if the antenna is stretched out in an area
where there is no metal it should do it's best. You probably won't benefit
from a counterpoise at all. In fact, any RFI you might encounter will have
to be specifically addressed because of the antenna is within the living
quarters. Your antenna will be too close to the ground and partly shielded
by roofing materials as it is for optimal performance, but we do what we can
just to get on the air when there is no good solution. Having said that, You
should be able to load up with an outboard tuner and make some contacts.

On 5-Aug-2009, "JB" wrote:

This is a balanced antenna and if the antenna is stretched out in an area
where there is no metal it should do it's best. You probably won't benefit
from a counterpoise at all.

The idea behind the counterpoise was to provide an RF ground for the radio, not as a part of the
antenna.

Your antenna will be too close to the ground and partly shielded
by roofing materials as it is for optimal performance, but we do what we can
just to get on the air when there is no good solution. Having said that, You
should be able to load up with an outboard tuner and make some contacts.

I have a friend with an Alpha Delta DX-EE in his attic, and he has achieved DX CC -- contacts with
100 countries. I don't know if it is a one or two story house. I'm going over to look at his
installation his weekend.

KJ4NTS wrote:
On 5-Aug-2009, "JB" wrote:

This is a balanced antenna and if the antenna is stretched out in an area
where there is no metal it should do it's best. You probably won't benefit
from a counterpoise at all.

The idea behind the counterpoise was to provide an RF ground for the radio, not as a part of the
antenna.


Ah, I'd never mind the counterpoise if you are using the balanced
antenna. Just put up the antenna, run the coax or ladder line, get
yourself a good station ground and some lightning protection. You are
not likely to get struck directly, but could be the victim of a large
static buildup. Polyphaser makes very good ones, and there is a simpler
one that uses a spark gap, which also provides protection. Don't know
the brand of that one. Disconnect the antenna and ground it when not in use.

I'd say with this setup, you could do DXCC. DXCC and other awards have
been achieved on more modest setups than what you are looking at
building. You won't be the loudest signal on the band, but there can
only be one of those anyhow.

Now get to work! 8^)


- 73 de Mike N3LI -

"Michael Coslo" wrote in message
...
KJ4NTS wrote:
On 5-Aug-2009, "JB" wrote:

This is a balanced antenna and if the antenna is stretched out in an
area
where there is no metal it should do it's best. You probably won't
benefit
from a counterpoise at all.

The idea behind the counterpoise was to provide an RF ground for the
radio, not as a part of the
antenna.

There is no need for the "radio" to have an RF ground.
If you are feeding the radio with 50 ohm coax that is matched in a 50 ohm
non-reactive load (ie tuner or dummy load) the RF will stay where it
belongs. The only concern for the balanced antenna, is lightning protection
and shock hazard from the power supply.
The best lightning protection depends on your specific situation so I will
leave you to read up on that.

Ah, I'd never mind the counterpoise if you are using the balanced
antenna. Just put up the antenna, run the coax or ladder line, get
yourself a good station ground and some lightning protection. You are
not likely to get struck directly, but could be the victim of a large
static buildup. Polyphaser makes very good ones, and there is a simpler
one that uses a spark gap, which also provides protection. Don't know
the brand of that one. Disconnect the antenna and ground it when not in
use.

I'd say with this setup, you could do DXCC. DXCC and other awards have
been achieved on more modest setups than what you are looking at
building. You won't be the loudest signal on the band, but there can
only be one of those anyhow.

I don't have DXCC but I do have a wall of cards from around the world. Many
of them were logged when I was mobile to and from work or school. It will
sharpen your skills to steal them from the big guns. I had a regular daily
lunch break sked with an Aussie from my truck in the parking lot.when the
sunspots were working. Conditions can even favor the well placed weak
station over the big guns. That is the sport of it all.

Now get to work! 8^)


- 73 de Mike N3LI -

On 6-Aug-2009, Michael Coslo wrote:

I'd say with this setup, you could do DXCC. DXCC and other awards have
been achieved on more modest setups than what you are looking at
building. You won't be the loudest signal on the band, but there can
only be one of those anyhow.

How much attenuation is a wood roof with asphalt shingles going to introduce? All of the duct work
in my house is in the crawl space, and the phone and cable TV lines are also in the crawl space. So
there is no metal other than the roofing nails, and there's nothing between the antenna and the sky
other than the roof decking and shingles. I don't expect them to add a lot of attenuation, but I
could be wrong.