Robert11 wrote:
For a receive only application, using coax from the Balun of a simple
outside antenna to the receiver, is a loss of, e.g., 2.5 db "meaningful" ?

Modern receivers have such a wide dynamic range that 2.5 dB
of loss on a received signal is usually of no consequence
at HF frequencies. Some hams don't even worry about that
amount of signal loss on transmit, ~ half an S-unit.
--
73, Cecil http://www.qsl.net/w5dxp