Dual 144/440 Vertical Collinear

A very simple antenna to make but you have to be VERY precise on the measurements. Basically you take RG-58 coax cable. Take the shield off in certain lengths while leaving the inner conductor and dieletric in place. I Suggest leaving the tip of the antenna a little long. You will initially be off in SWR but trim a few MM at a time until you achieve decent SWR across the 144 and 400 bands. Try and keep the bottom of the antenna connections (where the stub and main antenna meets) as short as possible.

I ended up getting a 1.3-1.6 SWR on 144 with a flat 1:1 on 440 which I needed to concentrate on more than 144.



I ended up drilling out 2 ends of a pepper shaker from a dollar store to allow the antenna to connect to a SO-239 chassis connector. A little bit of silicone seals the deal.