Amateur Radio

Hi I am looking for a little connection advice.

I use a radio on my narrowboat. As such I am in the process of building a simple random wire antenna. Idea being I have a 5m mast I can raise on the boat while moored. Then run a wire to a local tree or another portable mast.

The issue I am looking for some help with. Is finding connectors so I can set up different length antenna depending on available space.

I have a large kite winding wheel to store the wire with a 9:1 unun on the end. But need to be able to set up 3 different lengths. 143-84-(36 i think) feet. To do this I need some form of connector a lot stronger the your typical bullet crimp. The wind on the towpath and movement of the boat will separate such connectos easy. As the boat rocks. But anything much larger the a bullet will not roll around the kite reel well.

I am looking for some kind on single wire electrical connector. That screws together. So I can select the best length for the enviroment I am in. Unscrew the wire at that length. Commect it to an elastic rope attached to the tree or land based mast.

If the worst comes. I'll make something myself using m2 bolts and inset standoffs. But would love to know if anyone has seen something ready made that will do this.