All

I have just installed a 1/2 wave G5RV dipole at approx. 30 ft above
ground. My shack is in the back of the house but on the second floor
(effectively in the roof of the house) above the garden but due to the
house design i think i would struggle to have a RF ground wire of less
than 30-40 feet.

Based on above discussions should I :

1) fit a ground rod and run this up to the shack even though its a
long way up along various walls

2) buy an articial ground unit such as the MFJ-931

3) forget about it and make do without a ground.

I am pretty thoroughly confused.

Thanks

Andy

Andiroo wrote:
All

I have just installed a 1/2 wave G5RV dipole at approx. 30 ft above
ground. My shack is in the back of the house but on the second floor
(effectively in the roof of the house) above the garden but due to the
house design i think i would struggle to have a RF ground wire of less
than 30-40 feet.

Based on above discussions should I :

1) fit a ground rod and run this up to the shack even though its a
long way up along various walls

2) buy an articial ground unit such as the MFJ-931

3) forget about it and make do without a ground.

I am pretty thoroughly confused.

Thanks

Andy



Just operate and have fun. Finding a true RF ground is tantamount to
searching for the Holy Grail.

If your house utilizes metal radiators for heating, you might try
running a ground wire to a radiator and see if it helps.

Any antenna that requires a tuner for operation is most likely going to
have RF in the shack and on your radio. There really isn't much that you
can do about it, except juggle the length of the feedline, if you
operate mostly on one particular band.

Ed, NM2K

Thanks for speedy response. Therefore do i just need a DC earth on the
back of the radio and ATU?

Andy

Andiroo wrote:
All

I have just installed a 1/2 wave G5RV dipole at approx. 30 ft above
ground. My shack is in the back of the house but on the second floor
(effectively in the roof of the house) above the garden but due to the
house design i think i would struggle to have a RF ground wire of less
than 30-40 feet.

Based on above discussions should I :

1) fit a ground rod and run this up to the shack even though its a
long way up along various walls

2) buy an articial ground unit such as the MFJ-931

3) forget about it and make do without a ground.

I am pretty thoroughly confused.

Thanks

Andy


If you use a dipole antenna you don't need a ground. I would use your
option 1. If you decide
to use a vertical antenna then you can figure your ground conductor as
part of the antenna. I did
that when I was living in a town house
Bill K7NOM

Bill Janssen wrote:
SNIP
If you use a dipole antenna you don't need a ground. I would use your
option 1. If you decide
to use a vertical antenna then you can figure your ground conductor as
part of the antenna. I did
that when I was living in a town house
Bill K7NOM

Just think what a ground wire of 30 foot represents in terms of
wavelength, whatever it may be it will not be an RF ground!

As suggested, the best bet is to go for a balanced antenna such as a
dipole or set of dipoles. Use a balun at the antenna and feed with
coax straight to your rig/SWR meter. This works well for me in a
first floor shack with antennas in the loft.


Charlie.

--
M0WYM
www.radiowymsey.org

Andrio - Your situation is axactly like mine. G5RV, 2nd floor etc. The only
difference is that there is so much rock all around my property hat in most
cases I cannnot get an 18" ground rod down either After much
experimentaton, here's what I settled on:

Antennas:
I use an 80 m dipole with 'big ugly balun' and its coax shield is bonded to
a 40' large diameter aluminium cable buried in a 18" ditch.
I use a 20 m dipole with 'big ugly balun' and its coax shield is bonded to
ther 40' aluminium cable buried in the ditch.
I use an old 5-band cushcraft vertical with 15 radial wires laid out in a
hub-and-spoke pattern - and the coax shield of the vertical is bonded to the
same ground as all the other antennas before entering the house.

I had been using a G5RV but could never get a good VSWR and typically had
RFI around the house.

These antennas are ~40' from the shack and work as well as, or better than
the G5RV. Also, the G5RV tended to have more noise on receive (probably as
a result of it being closer to the house). The RFI in the house problem has
diminished. The G5RV was supposed to have the twin-lead portion laid out
directly under the antenna (vertical) and I never could accomodate that very
well given that the antenna was 28' up and the twin-lead was longer.

Grounding: Grounded the radio on the AC ground inside the shack Rig has
auto antenna tuner so that's the best I can do. I use a PC in the shack and
it is well bonded to the same copper connection plate as the radios - and a
single line from that plate to the ground pin on the nearest AC receptacle.
I get no interference into the HF radio from PC or vice-versa.

I've experimented with a MFJ RF isolator and not seen any improvement. Keep
us informed on whjat you decide to do - maybe some suggestions you get could
help me optimize this shack as well.

73

Kevin
VE9-XYZ

"Andiroo" wrote in message
oups.com...
All

I have just installed a 1/2 wave G5RV dipole at approx. 30 ft above
ground. My shack is in the back of the house but on the second floor
(effectively in the roof of the house) above the garden but due to the
house design i think i would struggle to have a RF ground wire of less
than 30-40 feet.

Based on above discussions should I :

1) fit a ground rod and run this up to the shack even though its a
long way up along various walls

2) buy an articial ground unit such as the MFJ-931

3) forget about it and make do without a ground.

I am pretty thoroughly confused.

Thanks

Andy