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-   -   2nd storey grounding (https://www.radiobanter.com/antenna/53569-2nd-storey-grounding.html)

kernelkole January 22nd 05 04:20 AM

2nd storey grounding
 
Of the solutions presented in the ARRL Antenna Book for 2nd storey
grounding...ha, ha! There are no solutions!

But that doesn't help me.

I live in an apartment - a set of rooms in a 100+ year old building, so
you'd THINK they'd have copper/metal plumbing; but, no. It's been
pvc'd. So no cold water pipe.

The ARRL cautions, and I concur, against dropping a long bit o' wire
from the window to the ground - many issues, including having the
ground wire function as a resonator, or, RF burns from touching th
radio. Don't want those.

There's the MFJ "artificial" ground, but I don't see how that would
work with the ATAS 100 I have - like having an antenna tuner for an
antenna tuner.

Any thoughts?

thanks,
kc0olm


[email protected] January 22nd 05 06:46 AM


kernelkole wrote:
Of the solutions presented in the ARRL Antenna Book for 2nd storey
grounding...ha, ha! There are no solutions!

But that doesn't help me.

I live in an apartment - a set of rooms in a 100+ year old building,

so
you'd THINK they'd have copper/metal plumbing; but, no. It's been
pvc'd. So no cold water pipe.

The ARRL cautions, and I concur, against dropping a long bit o' wire
from the window to the ground - many issues, including having the
ground wire function as a resonator, or, RF burns from touching th
radio. Don't want those.

There's the MFJ "artificial" ground, but I don't see how that would
work with the ATAS 100 I have - like having an antenna tuner for an
antenna tuner.

Any thoughts?

thanks,
kc0olm


What does the ATAS 100 feed, and where is it? Just use complete
antennas.
Myself, I wouldn't worry about it. You don't need a ground in the
shack for rf purposes, as long as the antenna is not fed directly from
the
shack. IE: random wire fed from a tuner in the shack, etc..I haven't
used
an rf ground in the shack for years. I would not waste any money on an
MFJ "artificial ground". MK


Hal Rosser January 22nd 05 06:50 AM


http://www.k0lee.com/durango.html

I don't have either the FT100 or the ATAS100, but according to this web
page, it looks like uhf/vhf stuff.
shux, man - in an apartment, you could mount it to a radiator, or fridge or
stove or metal cabinet - or railing

but if its hf - never mind
..



[email protected] January 22nd 05 06:55 AM

If I remember right, the ATAS is a HF auto tuner of sorts, usually used
for the yaesu mobile antenna...Sounds like he's trying to feed a mobile

whip with the auto tuner, at home. But just guessing...BTW, the FT-100
is
all band...HF-VHF-UHF...Kinda the yaesu equal to a icom 706....MK


Cecil Moore January 22nd 05 05:05 PM

kernelkole wrote:
I live in an apartment - a set of rooms in a 100+ year old building, so
you'd THINK they'd have copper/metal plumbing; but, no. It's been
pvc'd. So no cold water pipe.


There's the MFJ "artificial" ground, but I don't see how that would
work with the ATAS 100 I have - like having an antenna tuner for an
antenna tuner.

Any thoughts?


I have always solved that particular problem with a dipole
which requires no RF ground. However, lightning protection is
an entirely different matter. I just never worried about it
and never got hit.
--
73, Cecil http://www.qsl.net/w5dxp


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bob January 22nd 05 08:58 PM

For an RF ground, the connection from transmitter/antenna tuner to a good
ground should be a half wafelength long at the operating frequency. For more
frequencies, add more half wave wires. But dont coil the wires. hi the
height is less than about 0.1 wavelength, a straight wire connection is ok
Of course the usual rules for ground and connections apply.
w4mb



W9DMK January 22nd 05 10:53 PM

On 21 Jan 2005 20:20:18 -0800, "kernelkole"
wrote:

Of the solutions presented in the ARRL Antenna Book for 2nd storey
grounding...ha, ha! There are no solutions!

But that doesn't help me.

I live in an apartment - a set of rooms in a 100+ year old building, so
you'd THINK they'd have copper/metal plumbing; but, no. It's been
pvc'd. So no cold water pipe.

The ARRL cautions, and I concur, against dropping a long bit o' wire
from the window to the ground - many issues, including having the
ground wire function as a resonator, or, RF burns from touching th
radio. Don't want those.

There's the MFJ "artificial" ground, but I don't see how that would
work with the ATAS 100 I have - like having an antenna tuner for an
antenna tuner.


The only aspect of this that has not yet been presented adequately is
the artificial ground. I neither subscribe to nor recommend this, but
you should at least be aware of how it is intended to work.

The "artificial ground" has one end connected to your shack ground (in
your case the chassis of the transmitter or tuner will do nicely.

The other terminal of the "artificial ground" connects to a length of
wire that is just sufficient to connect to an earth rod driven into
the soil beneath the shack. The "artificial tuner" internals consist
of a series resonant circuit - a capacitor and a multiple tapped
inductor and an RF current detector. The "artificial ground" is tuned
for a maximum of RF current when your rig is transmitting. The
artificial ground with its length of wire from the rig chassis to the
earth rod makes up a series resonant circuit that is electrically an
integer multiple of a half wave. That presents the lowest possible RF
impedance between the chassis and the earth rod (as indicated by the
maximum of RF current in the artificial ground).

The effect of this will be to make the chassis of the rig "cool". It
will have no effect on the antenna tuner, but it will reduce the flow
of RF current through other devices in the shack via power cords.


Bob, W9DMK, Dahlgren, VA
Replace "nobody" with my callsign for e-mail
http://www.qsl.net/w9dmk
http://zaffora/f2o.org/W9DMK/W9dmk.html


Hal Rosser January 22nd 05 11:48 PM


wrote in message
oups.com...
If I remember right, the ATAS is a HF auto tuner of sorts, usually used
for the yaesu mobile antenna...Sounds like he's trying to feed a mobile

whip with the auto tuner, at home. But just guessing...BTW, the FT-100
is
all band...HF-VHF-UHF...Kinda the yaesu equal to a icom 706....MK


Okay - thanks for the info -
He just needs to move in with his downstairs neighbor.




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