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My Mast & Antenna Installation
This page details the installation of a mast and antenna at my house
(originally installed in April 2003),
providing me with a connection to the Martin Mast access point.
See here for details of the mast at my previous house.
Parts Required
We used the following bits and pieces:
- 3m galvanised pipe (32mm external diameter)
- modified Conifer (ex Galaxy) 24dBi antenna
- 3 guy wires
- 3 large eye bolts
- assorted ubolts and nuts and bolts
- coax
- silicone
I had previously obtained several 3m masts (including guy wires)
when I was collecting Conifer antennas from people's roofs.
The eye bolts were purchased from a local hardware store, and I used about 10m
of CNT-400 coax.
My PentiumPro with an Enterasys
RoamAbout wireless card, and an SVEC
WL-123 PCMCIA to PCI adapter,
running Red Hat 7.3, was going to be re-used for use as a wireless router.
Note: this box has now been replaced with a Red Hat 9.0 router
on a Celeron 466.
Testing
The Node Database
provides shows the location of access points, and also provides compass bearings,
distances, and elevation diagrams, and indicated that I should have line-of-sight
from my house to the Martin Mast access point.
elevation diagram from the Node Database
I have very clear line-of-sight to the MartinMast from this location, with
absolutely no trees or any other obstacles in the way.
looking towards the Martin Mast from the roof
This is a big improvement from my previous location,
where my signal was going through numerous trees.
Installation
The 3m mast was installed in the same way as Marcus' mast,
so I won't provide any details here.
Refer to my page detailing his antenna installation for more
details.
the mast mounted on the roof
Suprisingly, despite the fact that I'm now 1.9km closer to the MartinMast, with
very clear line-of-sight, I'm only getting an average SNR of about 9dB - about 3-4dB less than
what I was achieving at my previous house.
I'll be doing some further testing to try to determine why this is the case,
although I believe it may be due to the lobes in the elevation gain of the 180 degree waveguide
at the Martin Mast (despite the fact that the elevation from this location to the Martin Mast
is only 0.3 degrees higher than at my previous location).
Addendum
In January 2005, I added a 180 degree slotted waveguide to the top of the mast,
connected to a Minitar MNWAPB access point, to become
Seville Grove FreeNet (aka SGNet).
waveguide on the mast
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AP in the roof-space
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The ESSID is SGNet, with limited WAFreeNet access to
DHCP users (limited to IRC/HTTP/DNS).
Contact Martin for a subnet allocation if you want a
permanent connection to SGNet.
References
My Old Mast & Antenna Installation
Marcus' Mast & Antenna Installation
Modifying Conifer Antennas for Wireless Networking
Conifer Antenna Testing
Wireless Link Monitoring with RRDTool
last updated 22 Oct 2013
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