Re: Miniature HF antenna
For receiving you do not have to have any particular terminal impedance. Use a JFET source follower if connecting the 1.5 m length of wire to your receiver does not bring the bakground atmospheric noise high enough to notice in the receiver. Do this test at the low frequency end of the range.
The basis for this is that at this frequency range, the atmospheric noise is higher than the receiver noise figure noise. The SNR is already set in the E&M field before it gets to your electronics. Doing impedance matching to get the sum of the atmospheric noise and your signal into the receiver at a higher power level does no good in the output SNR.