I am currently building a two element portative cubical quad with one reflector and one driven element. the conductors of the driven element and reflector are encased in pvc tubing.

I was wondering what tuning stub design I could use for the reflector. I didn't find a lot in the literature.

Currently, I am thinking of a conductive bar bolted across two long screws. it would be quite precise for tuning.

Now for the choice of metal: it has to be a compromise between corrosion resistance, price and conductivity. I was thinking of corrosion resistant brass. for a better and more expensive design a silver or gold plated stub would be better, I suppose ?

Anyway, I have no idea of the best geometry for the stub. I suppose it has to have a decent spacing or it will behave like a transmission line.

Any ideas or references welcome.