Trying to build an extender using an antenna.

So i was just going through my grandpa’s old stuff he passed away 7 years ago and i found this old dual antenna and my god these antennas are strong as hell . That gave me this weird idea.

Making the holder at the front is easy i can use some Velcro bands and mod it out to hold the stretch and get a good grip below the glans. The problem is the base now i don’t know what to use still thinking about it please drop some suggestion down below if you can.

FYI= I’m doing this just out of curiosity and fun .