In order to be the best two element shorty forty, it would have to use the best
type of loading. I'm no expert in this area, however I do know that linear
loading efficiency can vary with the design of the loading wires and the
loading wires also radiate which may distort the beam pattern. I agree that a
loading coil is a simpler design. I needed such an antenna for my P40A station
and I wanted the best. I compared the Cushcraft XM240 and OptiBeam OB2-40. I
had previously owned a Cushcraft 402CD and I too had good results with it. I
believe that the XM240 is similar in design, except stronger. I'm not sure if
they solved some of the reported problems with their loading coils in the new
antenna model. It is reported that Cushcraft has good customer service. The
Cushcraft boom is about 3 1/2 ' longer and the Optibeam weighs about 7 pounds
more. The high Q air loading coils on the Optibeam are significantly larger
that the Cushcraft and likely much more efficient. Th
e OB2-40 also has detuning stubs to help avoid interaction on other ham bands.
I chose the OptiBeam and I installed it in March 2006. The OB2-40 arrived
pre-measured and it was a snap to put together. It is well made, hopefully it's
strong enough to survive Aruba's constant wind. All of the hardware was
stainless steel and they even supplied u-bolts to fit my 2 1/2" diameter mast.
OptiBeam's customer services is outstanding. Tom (DF2BO) answered all of my
pre-purchase questions promptly and he even modeled the OB2-40 along with my
homebrew 4 element 20m 7' below it to check for interaction problems.
John KK9A
----- Original Message -----
From: K7LXC@aol.com
To: towertalk@contesting.com ; john@kk9a.com
Sent: Friday, September 15, 2006 9:28 AM
Subject: Re: CC 402CD - a great antenna
In a message dated 9/14/2006 7:15:07 P.M. Pacific Daylight Time,
towertalk-request@contesting.com writes:
> What makes the Cushcraft 402CD the best shorty forty ever made?
Well, it was the first reasonably priced 40M yagi and it provided decent
40M performance to the masses.
So it was reasonably priced, a simple design (no linear loading) and had
250 kHz of bandwidth. None of the competitors can make those statements.
Cheers,
Steve K7LXC
TOWER TECH
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