Hi - I have a portable radio I am tinkering with, so far
superficially. It has a ferrite bar inside for AM and SW reception up
to 6 MHz with no provision for an external antenna. The ferrite bar
works great on AM, but as you might guess, the SW reception is short-
changed.

To start with, I was thinking of getting another ferrite bar about 10"
long, wrapping a few turns of wire around it (probably try several
turn values to see what works best), mounting it on the back of the
radio broadside to the internal ferrite bar, and then hooking the
leads up to my external wire antennas. Any reason why this would or
would not work for better reception near 4-6 Mhz? Would an end-to-end
configuration be better?

Thanks,
Bruce