If your antenna is very short in terms of wavelength, then shunt
capacitance will reduce the amount of received signal. Solutions include
running the antenna wire directly to the receiver, using a preamp at the
antenna, or using a short length of special high-impedance coax as
feedline. The latter is what's commonly done with automotive AM radios.

If the antenna isn't very short, then "tuning" is done by means of a
matching network, which can compensate for mismatched coax line and the
impedance transformation it causes.

Roy Lewallen, W7EL

mike wrote:
When researching the cost of high impedance coax as a feedline, it
apears globs of coax induced capacitance seriously degrates the
ability to tune the circuit. Under these conditions, resonating
frequencies requires extremely low inductance values.

How do people get around this problem in a receive only situation?

thanks,

mike