He wants multi band operation. Therefore he needs traps to provide the
necessary isolation for 40 and 20 meters.

Dave wrote:

for an 80-40-20 dipole you don't need 'traps' to shorten the 80m piece you
need 'loading coils'. 'traps' have a resonance that effectively cuts off
the section of the wire past them making the inner part resonant on the
higher frequency, so you need 'traps' for 20m and 40m. 'loading coils' are
simply an inductance that makes the section appear longer than it physically
is.

"Vinnie S." wrote in message
...

I want to construct a 80-40-20 meter dipole, but want to trap the 80 meters
to
shorten the length. Does anyone know where I can get good quality traps? I
am a
beginner as far as antenna theory.

Vinnie S.