Irv Finkleman wrote in :

Is a copper to copper contact always necessary in
an antenna or does solder provide the necessary
continuity when joining wire?

Are you really asking are conductors other than copper (eg solder) are
suitable for antennas? I think you know the answer to that.


I am disregarding the special case of magnetic
loops where RsubA must be kept low. I am also
disregarding the matter of mechanical integrity.

In my case I am looking at soldering radials to
a piece of copper wire at the base of an antenna, and
also adding a bit of length to the radiating
element.

I note you excluded mechanical integrity, nevertheless...

I suggest you not depend solely on solder for retention of wires. One
day, your antenna conductors might be called upon to carry high current
(eg lightning), and it might be better if the solder didn't just melt and
allow the wires to fall apart.


What about the use of wire nuts to join wires?


In some ways, you might as well just twist the wires together. Some wire
nuts come with a water+air exclusing medium (grease), but otherwise they
are not a lot different to twisting the wires together except they may
introduce another metal (in the case of the ones with a metallic spring
inside) to the contact mix. Twisting wires together might be more
successfull for power applications where there is sufficient voltage to
overcome an oxide layer, for RF receive I would use solder or terminals
that apply considerable pressure to the joined wires.

Remember that oxided wire connections can cause havoc with receivers and
transmitters, the non-linear joint causing harmonic generation and
mixing.

Owen