|PAR (LNR Precision) End Fed Half Wave Antenna... My experiences with the
Par 20 meter EFHWA and my own 10 meter version that Im building up to try
out. (I guess I can call my own homebrew version: A Par-style EFHWA.
Final preparation to go outside. I had to use a piece of solid wire to form
a loop for hanging the antenna from the tower.
My tower is next to the house and is a TV type tower up about 29 ft or so
at the top.
I sold my little rotatable MINI beam and am now considering building a
quad this spring. I have all the parts for a boomless quad and it will be
for 6, 10 and maybe one other band (possibly 12 meters).
For the winter ..I will be putting up these PAR style antennas. I want to
put one up on 10 and I want to build another one for 6 meters.
Last night I was doing some listening on 20 meters with my PAR (LNR
PRECISION) end fed half wave. Most of the time ..the Par and the
Vertical in the back yard were about the same strength. I was copying an
RU station significantly stronger on the PAR than the vertical. This is
because my PAR EF-20 is sloping off the tower and favouring this
direction. The vertical is my homebrew screwdriver style vertical which
can be adjusted for any frequency. I had it adjusted for 20 meters while I
was doing this listening test.
This is the PAR (LNR Precision) EF 20 (300 watt version) at the top of my tower. It
slopes down at a 45 degree angle. Right now ..it is favouring NORTH NORTH WEST.
I plan to change it to favour Europe (soon). The tower probably interacts with this
antenna). I might plan to erect a fiberglass mast to the side of the tower and get
the antenna up another 8 feet. This depends on the weather. I can still work on the
tower and antenna even if it is winter.
I put the homemade matchbox up the tower/ladder combination up about 15
feet or so from the ground to perform an swr test.
This 10 meter antenna (I cut the wire at about 16 ft 6 inches or so). I knew the wire
was probably a little long and might need to be trimmed. I had a couple of spare TV
tower sections and I used one of them to tie off the antenna at around arms length
above my head.
Heres a shot looking down the wire up towards the match box.
Above the small backyard tower. The 20 meter EF-20 is near the top of the tower
and you can make it out if you look closely. It slopes off the tower towards the
North favouring Russia. Above picture close up you can see the match box and
the yellow rope sloping towards the shed.
BELOW: THE SWR CURVE taken with the SWR analyser.
Pictures as well of the testing below:
Taking the measurements. I am very pleased with these results. NOW..I have to take the antenna
down from its temporary location and I'm going to trim a wee bit off the wire to get the resonant point
up higher...say around 28.3 mhz or so.
I also have to finish off the match box. I want to seal it with a gasket sealer on the inside mating edge
of the lid and I want to make sure all the connections are tight and well soldered down. I will be
writing more about using this antenna (on these pages) in the next week or so. 73 Earl VE3Ab
|I am 'thinking about' selling parts to make this match box.
Sort of a kit or kit let. I can sell the coil..measured the same inductance and
the coax capacitor and a page with schematic and parts layout format for
$13.00 plus postage. Just write me email@example.com or
firstname.lastname@example.org -- I cannot sell the box as I don't have many. NOTE: If you
have ideas on an enclosure..let me know..I'll go out and buy some! Prices
are in US dollars and I have a Pay Pal account. 73 Earl VE3AB PS..I could
probably make up custom matching networks for other bands as well and I
might even be able to make a QRO version. -- MY serious operating is QRP
contests on CW.