I'm sure it's not much of a performer, nelson. If you're using speaker
wire as your feeder, it's going to be horribly mismatched. Your trx
expects to see 50 ohm on the antenna, and (though I'm not certain) I'd
be willing to bet that your speaker wire is either much higher or much
lower. At best, this will give terrible performance. At worst,
potentially blow up the output stage of your rig.
RG58 is the coax you need. It's cheap, sometimes free. It's the same
stuff old 10base2 networks used to be wired with, so a visit to a dump
will probably turn up loads.