Here's something you can make for next to nothing, The capacator was bought at a rally for £1, the coil is made of soft copper 13Amp wire, the antenna wire is one of the windings of an old transformer.
It took about 3 months to hear 180/324 Maidenhead squares on this wire.
First, I soldered the three capacators in parallel, with a nice stiff bit of wire (ring mains). Stripped the centre conductor from the coax braiding, about 6 inches, cut the braid, leaving about an inch.
Cut a slice out of the centre insulation, about an inch down from where they part and solder this to the capacator. Bring the end of the centre conductor to a croc-clip and insulate!
Now take the braid and solder a tag onto it. Solder another tag to one end of your coil. Using a suitable screw, both tags go to the capacator body.
If you intend to use this antenna for transmitting, (don't laugh) insulate (a) the tuning knob & (b) the croc-clip.
Just a final note: a thin antenna wire seems better than a thicker one of equal length for some reason, I have found it gives lower SWR and better bandwith.