[Antennas] 2m 70Cm colinear

[vk6jb]

Greetings all,
I was told by a friend that it might be possible to
get a diagram to construct a dual band collinear
and i am writing to ask if anyone has any detailed
diagrams or a link to any site that may have
detailed construction and tuning  for this type of
antenna.
I know that some commercials make them but are to
high a price.
If you can help i would be very grateful.
Any hints, tips, or other constructive details
would be very welcome.
73's,
De John
Amateur Radio Station VK6JB
E-mail : vk6jb at amnet.net.au