The plumbing codes in the U.S. requires that the sewer
drain pipes in homes and other buildings be vented to the outside air
and require that there is one or more vent pipes up on the roof to vent
sewer gas outside. In case you don't already know, the sewer vent pipe
on the roof looks similar to the photo below.
2 vent pipes are on the roof pictured above....located in
the left middle and right lower part of picture. The large wind turbine
in upper part of picture is for attic ventilation.
from the ground.
By using one of these
vent pipes as an antenna location mounting idea for a
2/440 band ground plane antenna and making it "stealth" in the process,
we offer the following as a suggestion or idea for you if you live
in a hoa or antenna restricted situation and want to "hide" (go
stealth), a 2 or 440 band antenna up on the roof. Even if you are
not hampered by the hoa situation, this is a good method of supporting
your 2/440 band antenna.
This method will work best and be more
safe for YOU during the installation if you live in a single story
house, apartment, etc. If your residence is more than a single
story, be very careful and get help if needed. Be extremely careful on
severely pitched roofs!
If you look very carefully in the mockup photo above, you
should see the ground plane antenna mounted on the side of the vent pipe
nearest to the upper part of the roof on the "back" side of the vent
pipe as viewed from the ground. The copper colored lines represent the
actual antenna elements and the black line represents the coaxial cable
leading down the roof surface to the transceiver inside the
In the next "doctored" photo below you
should see what this "may" look like IF you painted the antenna
elements, the mounting, and the coax to match almost
exactly the background as seen from the ground. You have to look
very close to see the antenna elements and the coax. Painting the
"antenna system" that is visible from the ground and its mount
to match the background of the roof and vent pipe color will be the
most difficult part of this idea. Here is where the "stealth" may help in keeping it almost
invisible from the ground.
the roof shingle design has darker horizontal separations
between the shingles as in the photos here, try to add "horizontal"
paint marks on the vertical and radial elements of the antenna. This may
help with blending of the roof pattern to the antenna. Use your own
This is not an actual installation
shown in the photo above but it demonstrates a bit of Windows Paint
"magic" in making the coax and the antenna elements become almost
So how do you build and mount a 2 meter
or 440 band ground plane to the vent pipe? See this article for
plan ideas for a ground plane antenna and its support.
the formulas provided in it and you will be close with some small bit of
tuning required for lowest swr.
The actual mounting will depend on the size
of the vent pipe diameter and how YOU want to mount it. There are many
options. Use your imagination as required. Keep the mounting as simple
as possible to reduce visibility from the ground and from the street if
the vent pipe is located on the street side of the roof.
If the selected vent pipe location is
more near the peak of the roof as viewed from the street, then it would
be best to route the coax over the peak of the roof and then back down
to the radio room. However, use the shortest length of coax leading to your 2
radio as possible given your circumstances.
Here is one idea you may want to try for a
support for the ground plane:
Photo shows ground plane
antenna mounted to end of short length of PVC.
See this article for reference on mounting
and building the ground plane antenna to a short length of PVC pipe
which is then attached to the back side of the vent pipe in our