Lining up full size single band REFLECTORS is a GOOD idea.
Unfortunately, when parasistic DIRECTORS are lined up, the
lower frequency elements act as inefficient reflectors in FRONT
of the higher band elements, therefore, multiband directors are
used to prevent these undesired effects.
The Cushcraft X7 and HyGain TH11 are good examples of
commercial antennas using full size reflectors and trapped
directors (along with log cell driven elements).
A GOOD simple 2L tribander can be built using a split dipole
Driven Element (old Mosley or HyGain DE) combined with
single band parasitic reflectors on a 10 to 12 ft boom.
The TELREX TB4 was such an antenna. Add a trapped
director on an 18 ft boom for a little more gain and F/B.
The TELREX TB5 is an example of this approach.
On Tue, 09 Oct 2001 ABowenN4OO <email@example.com> writes:
> Several years ago, I put up a second hand CL33. Daily skeds with a
> operator on the W7-KL7 run, showed a drastic reduction in
> performance from
> the previous antenna. Subsequent investigation showed a defective
> coil, apparently damaged by a lightning strike.
> I rebuilt the reflector element to make it full size (36' mol),
> added a
> full size 15M reflector and ignored 10M because of low activity
> there. The
> change in performance was amazing. Even 10M was improved and I
> added a full size reflector for that band also.
> I did not pay much attention to SWR values in those days because we
> used tube type rigs which did not seem to care much.
> Check your parasitic elements for opens or shorts. Full size
> elements may improve performance even more. It is very difficult to
> optimum performance on 3 bands with elements containing traps.
> Studying the K7LXC/NoAX HF TRIBANDER PERFORMANCE reports confirmed
> INK N4OO
> List Sponsored by AN Wireless: AN Wireless handles Rohn tower
> Trylon Titan towers, coax, hardline and more. Also check out our
> supporting towers up to 100 feet for under $1500!!
> FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> Submissions: firstname.lastname@example.org
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: email@example.com
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!! http://www.anwireless.com
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Administrative requests: towertalk-REQUEST@contesting.com