Station ground/2nd floor
 

I'll be moving my rig to a second floor OP here soon, I've always been
at/below ground level with a short run to a ground rod. I'm only
running a trap dipole nowdays and I don't want to get into the mess of
a counterpoise. Can I/will I get an acceptable ground by running a
ground strap to a ground rod? I imagine that a lot of folks are doing
this - is there any advice regarding getting it grounded from this
height?

tnx - Mark/n0lf

Station ground/2nd floor
 

Mark,
Sounds like a 'balanced' antenna to me, why a
ground other than for electrical purposes (not RF)?
- 'Doc

Station ground/2nd floor
 

I needed to hear it from somebody else, that's all.

I'm not quite balanced in the feed, as I'm using coax out to the
dipole feedpoint, but probably close enough.

tnx - Mark

On Sun, 27 Nov 2005 17:27:04 GMT, 'Doc wrote:

Mark,
Sounds like a 'balanced' antenna to me, why a
ground other than for electrical purposes (not RF)?
- 'Doc

Station ground/2nd floor
 

Mark Sheffield wrote:
I'm not quite balanced in the feed, as I'm using coax out to the
dipole feedpoint, but probably close enough.

A W2DU choke would probably eliminate the need for
an RF ground and also be good engineering practice.
--
73, Cecil http://www.qsl.net/w5dxp

Station ground/2nd floor
 

I have a 2nd floor shack too, and the antenna is a ground mounted vertical
(Butternut HF6V). I use a W2DU choke to connect my coax feedline to the
vertical and a 2nd W2DU choke between my Orion and Drake L-4B. Finally, I
found that the only way to prevent feedback on SSB was to NOT connect my
system to the #8 ground wire that runs out the window sill and down to a
ground rod.

"Cecil Moore" wrote in message
. com...
Mark Sheffield wrote:
I'm not quite balanced in the feed, as I'm using coax out to the
dipole feedpoint, but probably close enough.

A W2DU choke would probably eliminate the need for
an RF ground and also be good engineering practice.
--
73, Cecil http://www.qsl.net/w5dxp

Station ground/2nd floor
 

John, N9JG wrote:
Finally, I
found that the only way to prevent feedback on SSB was to NOT connect my
system to the #8 ground wire that runs out the window sill and down to a
ground rod.

Yep, everyone should realize that a ground wire is N*1/4 wavelength
at certain frequencies, and at those frequencies, is an RF transformer
that locates the standing-wave voltage maximum points at the transmitter. (ouch!)
That's what artificial grounds do - change that *electrical* length
to N*1/2 wavelength. For anyone insisting on an RF ground for an upper
floor, an artificial ground is probably the way to go. I, myself, prefer
balanced antennas and feedlines.
--
73, Cecil http://www.qsl.net/w5dxp

Station ground/2nd floor
 

Cecil Moore wrote:
Yep, everyone should realize that a ground wire is N*1/4 wavelength
at certain frequencies, and at those frequencies, is an RF transformer
that locates the standing-wave voltage maximum points at the transmitter. (ouch!)
That's what artificial grounds do - change that *electrical* length
to N*1/2 wavelength. For anyone insisting on an RF ground for an upper
floor, an artificial ground is probably the way to go. I, myself, prefer
balanced antennas and feedlines.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil, Don't you mean that when a ground wire is N*1/4 wavelength at
a particular frequency it locates the voltage mininum (current maximum)
at the transmitter, and the voltage maximum well away from the
transmitter. Artifical grounds use a series LC circuit to try and tune
your ground wire to look like 1/4 wave. If they change the
*electrical* length to 1/2 wave then you would have a voltage maximum
at the transmitter (ouch!).
Gary N4AST

Station ground/2nd floor
 

Cecil Moore wrote:

John, N9JG wrote:
Finally, I
found that the only way to prevent feedback on SSB was to NOT connect my
system to the #8 ground wire that runs out the window sill and down to a
ground rod.

Yep, everyone should realize that a ground wire is N*1/4 wavelength
at certain frequencies, and at those frequencies, is an RF transformer
that locates the standing-wave voltage maximum points at the transmitter. (ouch!)
That's what artificial grounds do - change that *electrical* length
to N*1/2 wavelength. For anyone insisting on an RF ground for an upper
floor, an artificial ground is probably the way to go. I, myself, prefer
balanced antennas and feedlines.
--
73, Cecil http://www.qsl.net/w5dxp

Why not run two ground wires in parallel -- one twice as long as the
other? When one is Hi-Z the other will be Lo-Z and vice versa.

Irv VE6BP
--
--------------------------------------
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Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
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--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

Station ground/2nd floor
 

wrote:
Cecil, Don't you mean that when a ground wire is N*1/4 wavelength at
a particular frequency it locates the voltage mininum (current maximum)
at the transmitter, and the voltage maximum well away from the
transmitter.

Nope, Mother Earth dictates the boundary conditions. A well-designed
ground system positions the current maximum point at the ground system,
i.e. minimum impedance to ground.

The voltage maximum point would, therefore, be located at the transmitter,
not a desirable condition. Of course, if you are not actually connected/
coupled to Mother Earth, your milage may vary.
--
73, Cecil http://www.qsl.net/w5dxp

Station ground/2nd floor
 

Irv Finkleman wrote:
Why not run two ground wires in parallel -- one twice as long as the
other? When one is Hi-Z the other will be Lo-Z and vice versa.

That will help on some frequencies but it is akin to trying to
erect a 1/2WL fan dipole for all frequencies - can't be done. Sooner
or later, you will run into a frequency where length #1 is N*1/4WL
and length #2 is (N+1)1/4WL. "It's not nice to fool Mother Nature."
--
73, Cecil http://www.qsl.net/w5dxp