[SECC] 6 meter beam

[David Thompson]

Several years ago I bought a 6 el Cushcraft beam from Ron W4WA.  I brought
it home and got a stiff warning from VHF Contesting guru W3ZZ (ex K1ANV)
that the older design Cushcraft left much to be desired.

I pulled the 5 el and 6 el manual from the cushcraft page (for free).  First
off I noticed that the elements
were now all one size center with smaller pices of aluminum telescoped to
make the element ull size.  This changes the parameters in a modeling
program as to spacing and length.

I did not have room in the space available (attached to my chimney) to use
the full 20 foot 6 el version.  So I opted for the 5 el on about 11 foot
boom of the 605S
manual.  I made the lengths exactly the size per the manual and spaced them
as per the manual.  On NEC4WIN it looked good but the gain was only 6.9 dbi.
I then made changes to the element lengths and found that adding to the
reflector 2" and shorting the 3rd and 4th directors (the element spacing was
fine) that I was looking at 8.4 Dbi.  The only way to make further increases
was to lengthen the boom to 14.5 feet which was not an option.  I ran these
by Joe W1JR and he agreed they looked good...he designed the 605 and 606S.

I would not pay the price current price for the newer version but would copy
the 605 or 606S design including the tubing sizes since you can download the
manuals.  This way you only use two sizes of aluminum but your still have to
fashion the gamma match.  For the less brave you can probably buy the gamma
mechanism from Cushcraft.

I tried the 5 el three times and working stations was much easier than with
the 4 el Comet HB9CV beam
(11 foot boom).  Both antennas were on a military mast 6 feet above the
chimney and about 35 feet above the ground.  Using the FT-920 barefoot the
guys on the 6 meter net said I was loud and I worked two in Europe on SSB
that I could not make with the 4 el.

The only cost was the original cost of the old beam and some work in doing
the modeling and adjusting the element lengths.

Don't have an antenna and want to get on?  I found that my 2 el cushcraft 40
worked Ok.  I worked 23 countries (NA, SA) and many states (bunches of W6
and W7).   Other SECCers in Alabama used their 15 meter beam with good
success.

73 Dave K4JRB