Just Curious wrote:
Hi, would anybody know (or like to know?) the "secrets" hiding in the pvc
tube antennas like Dressler ARA-500, 900, 1500, 2000 LF-Engineering H800,
etc. What kind of element is used as antenna, also the config of the preamp.
and the semis used? Their overall efficiency? I know my questions are many
fold but still I'd like to know. Thanks to All. Just Curious.


No secrets, just a short and probably simple antenna and low noise
amplifier. The antenna is likely to be a simple monopole which would be
no longer than about wavelength at the highest frequency to ensure low
angle omnidirectional response. There's no practical way I know of to
define the efficiency of an active antenna. Other than amplifier noise
figure, what would separate a good active antenna from a bad one would
be the dynamic range of the amplifier -- poorly designed ones would be
prone to overload and spurious signal generation from strong signals.

Roy Lewallen, W7EL