... 2m Yagi from recycled discards
|A 2m, 6 element beam
built from neighborhood garbage!
Here in Phoenix, we have a wonderful
program called "Bulk Trash Week".
Every 3 months, Phoenicians are
encouraged to place their large,
bulky discards at curbside for one week.
Scavengers (that's me) are encouraged
to rummage through the discards
and to take anything that they think
they can use.
After the week of "rummaging" the city
trash trucks come around and pick up all
the remaining discards. End result, we all
get to get rid of our old, dead appliances,
building materials and furniture, the
landfills are a little less crowded, AND
the desert wilderness gets a little LESS
filled up with discarded couches and refrigerators.
This 2m, 6 element Yagi antenna
was built entirely from discarded items
that I found during "bulk trash week"
|Boom, Elements, Mast...
all recycled discards
The boom is a recycled fiberglass
telescopic tree pruning pole.
Originally yellow, it's now
my signature camo paint scheme.
Reflector, driven element and directors
as well as all the hardware, clamps,
nuts, bolts, even the mast, are recycled
from a TV antenna that someone threw out.
Recycling the aluminum elements was simple.
I drilled out the existing rivets that
held the original TV antenna together.
That left me with several tubular aluminum
elements, several aluminum hold down clamps
and a bunch of scrap elements to use to
reinforce the mounting joints.
from recycled parts
The gamma match was made from
the same TV antenna parts.
The outer sleeve of the gamma
is a piece of TV antenna element.
The inner concuctor of the gamma
capacitor is a section of what was
originally the phasing wire on the
The dialectric is a piece of rubber
fuel line. That rubber hose wasn't
part of the TV antenna, but it was
a 'throwaway' that I rescued from
someone's bulk trash.
Even the SO239 is a salvage from a
discarded CB radio.
|Testing the Trashbeam
for SWR, reactance,
The tripod stand I use for testing
is a piece that someone discarded as trash.
I slid the mast (recycled of course)
into the tripod stand, connected a
length of (recycled) RG58 coax,
connected and powered up the
I initially guessed at the gamma match
measurements. Initial SWR was greater
So I guessed again, moved the slider clamp
a little bit and read the meter again.
Here's the readings
from the MFJ analyzer...
From 144 to 148 MHz
SWR is -
Best case 1.1:1
Worst case 1.3:1
Reactance is -
Best case 4
Worst case 10
I try and shoot for
a max reactance of 10 for any antenna.
I've achieved that with the Trashbeam
Impedance is -
Highest at 62 ohms
Lowest at 43 ohms.
Prior to my applying the
camo paint, I was actually
able to achieve a perfect match.
Impedance was 52 ohms
Reactance was 0 ohms
SWR was 1:1
Applying the truck bed liner coating
followed by the camo paint changed the
resonance/capacitance of the Trashbeam
a tiny bit. But it's stil well
The spray on truck bed liner stuff
and the three colors of spray paint
for the camo effect, were the only
part of this antenna that cost
anything. They were left over from
previous projects so I didn't have
to go out and buy new paint. But I
did spend actual money on paint
at one point in time. Everything else
about this antenna was 100% free for
the taking from neighborhood
bulk trash day.
Rapid Deploy Station
Urban Desert Ops
EMT Conduit Antenna
Recycled 2m Yagi
Mil Mobile Base
6m Ground Plane
Return to QTH
The rest of my life?