OT: Stealth Indoor Antenna Questions

[Jeff-229]

Hi gang,

I'm going to install an indoor antenna to be fed by my K2, and I'm
considering using this 30-gauge wire for it: http://tinyurl.com/yjjcen  This
wire would be great aesthetically, because it has white insulation to match
my walls and ceiling.  The main question is, Can I get away with running my
K2 at 15 watts into such a miniscule gauge of wire?  30-gauge is awfully
tiny.  Should I limit my power to 5 watts at all times (which I would hate
to have to do, since I've found that the extra 4.5 dB sometimes makes all
the difference)?  Or do I need a bit thicker wire, even if running only 5
watts?  Each leg of this bent-to-fit antenna will be about a quarter
wavelength on 80 meters, and I'll be using it on all bands with the KAT2
tuner.

Does anyone know where I can buy a slightly thicker gauge wire, such as
26-gauge, that has white or off-white insulation?

One more question:  I plan to run the wire along the line where the wall and
ceiling meet.  What inconspicuous means would you use to hold the wire in
place?  I'm thinking of white thumb tacks or clear push pins.  I'm afraid
that anything sticky, such as Scotch tape, will come unstuck, requiring me
to borrow an extension ladder to re-stick it, as I have a "cathedral"
ceiling, which is way up there.

Thanks very much in advance for any advice.  Most of the antenna will be up
27 or 28 feet, by virtue of being on the third floor, so I'm hopeful that it
will work pretty well, at least in comparison with most indoor antennas.

Thanks again, 73 & 72,
Jeff
WB5GWB
Long Island, NY

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[Ron D'Eau Claire-2]

I've used that same wire in "stealth" indoor antennas at power levels as
high as 50 watts with no problems at all.

Thumb tacks or push pins are FB. I prefer the white or clear push pins and
put a loop of the wire in a "half hitch" around each pin so it remains
tight.

Using such an antenna following a high cathedral ceiling on the second
floor, I had excellent results, especially on 40 and 20. You should do very
well indeed being on the third floor.

The disadvantage of such wire is its ohmic losses at RF. It's the surface
area, not the cross-section, of the wire that determines RF resistance. If
you double the diameter of the wire, you increase the surface area by 3
times. If you really want to go for the "gold" and reduce the losses, run
two or three wires in parallel. The RF currents will flow over them just
like a "fatter" wire, and the currents will be shared among all the wires
reducing ohmic losses. That's exactly what the old radio coils used. It was
called "Litz" wire, and consisted of several separate inductors insulated
from each other but braded together and connected in parallel at each end.
It formed the lowest-loss for the size conductors available and is still
prized among builders who need large, efficient coils today.

In one apartment on the top floor where I could get into the attic, I
installed a doublet and fed it with open wire line made from this wire. Two
tiny holes in the ceiling where it met the wall brought the two wires of my
"open wire" line down the wall to the ATU on my desk. They were held against
the wall with push-pins. I actually had visitors sit at that desk and
couldn't see the "open wire" feeder until I pointed it out.

Ron AC7AC


-----Original Message-----

Hi gang,

I'm going to install an indoor antenna to be fed by my K2, and I'm
considering using this 30-gauge wire for it: http://tinyurl.com/yjjcen  This
wire would be great aesthetically, because it has white insulation to match
my walls and ceiling.  The main question is, Can I get away with running my
K2 at 15 watts into such a miniscule gauge of wire?  30-gauge is awfully
tiny.  Should I limit my power to 5 watts at all times (which I would hate
to have to do, since I've found that the extra 4.5 dB sometimes makes all
the difference)?  Or do I need a bit thicker wire, even if running only 5
watts?  Each leg of this bent-to-fit antenna will be about a quarter
wavelength on 80 meters, and I'll be using it on all bands with the KAT2
tuner.

Does anyone know where I can buy a slightly thicker gauge wire, such as
26-gauge, that has white or off-white insulation?

One more question:  I plan to run the wire along the line where the wall and
ceiling meet.  What inconspicuous means would you use to hold the wire in
place?  I'm thinking of white thumb tacks or clear push pins.  I'm afraid
that anything sticky, such as Scotch tape, will come unstuck, requiring me
to borrow an extension ladder to re-stick it, as I have a "cathedral"
ceiling, which is way up there.

Thanks very much in advance for any advice.  Most of the antenna will be up
27 or 28 feet, by virtue of being on the third floor, so I'm hopeful that it
will work pretty well, at least in comparison with most indoor antennas.

Thanks again, 73 & 72,
Jeff
WB5GWB
Long Island, NY

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[Leigh L. Klotz Jr WA5ZNU]

As I posted once before, watch out for safety issues with someone
running into nearly-invisible wire if one of the push pins should give
way.
73,
Leigh/WA5ZNU
On Wed, 6 Dec 2006 8:57 am, Ron D'Eau Claire wrote:
> They were held against
> the wall with push-pins. I actually had visitors sit at that desk and
> couldn't see the "open wire" feeder until I pointed it out.
>
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