Kristinn:

If you are willing to run lots of power into the test antenna at your
station, then a simple remotely located whip will do. But, if you are going
to look at elevation angle of emission rather than ground wave only, then
you will find that you need the equivalent of a full professional antenna
range to get repeatable data. Most non-professional configurations show
only +/- 3 dB of repeatability, so 1 or 2 dB improvements in antennas are
invisible.

--
Crazy George
Remove NO and SPAM from return address
"Kristinn Andersen" wrote in message
om...
Does anyone have a suggestion for constructing a simple, compact,
receive-only antenna, that covers reasonably well the HF range (1,8 to
30 MHz)? My plan is keep such an antenna as a constant reference when
I am experimenting with the "real" antennas at my station. Comparing
signal strenghts on the antennas over some time would at least give me
a reference on whether directivity in certain directions was improving
or not, when replacing one antenna with another.

The antenna would have the following characteristics:

- Simple (home-made, inexpensive, preferably not using any pre-amps).
- Small (not taking up space among my other antennas, non-intrusive).
- Receive-only (little need for elaborate matching, power handling).
- Connected through a coax, which should not pick up the RX signals.
- Broadband (preferably 1,8-30 MHz).
- Omnidirectional (or reasonably so, don't want any sharp nulls).
- Receive, to some extent, vertical and horizonal polarization.
- (Any other characteristics that should be included?)

I have thought of using a short whip or a loop for this (say, 1m/3ft
max. dimensions), but these both are rather selective in terms of
polarization and directivity.

Any suggestions or comments?

73 de Kristinn, TF3KX

The business of comparing performance makes sense if you are designing or
building antennas and are looking for comparison or improvement between them
(particular antennas). Having "standard" vertical or dipole makes sense only if
you have them on the same height as other "better" antenna and looking for gain
over single radiator.
Comparing say 3 el. beam, or long wire to vertical is mostly meaningless,
different patterns, polarization.
Using modeling program gives one idea about relative performance of various
antennas. Building them gives very close picture how they should perform. If
you really want to compare or measure gain over vertical/dipole standard (at
the same height) than do that. One can generally get pretty good idea how
different antennas work from the models (software) and if you want to optimize
or verify real antennas, the best way is do it on say scaled 2m model. Then
there is comparison with neighboring stations for the ultimate test.

GL Yuri, K3BU

I may be missing something here, but why not produce a
gain or field pattern for each antenna on the same
signal, random or otherwise and overlay each pattern
and put in memory? ( cheap laptop and use a loop antenna
for reference )

In one of the early antenna compendiums ( ARRLL)
a Peter Dobbs of the U.K. supplies all the info
and program to get you onboard quickly and inexpensively.
Art

I may be missing something here, but why not produce a
gain or field pattern for each antenna on the same
signal, random or otherwise and overlay each pattern
and put in memory? ( cheap laptop and use a loop antenna
for reference )

In one of the early antenna compendiums ( ARRLL)
a Peter Dobbs of the U.K. supplies all the info
and program to get you onboard quickly and inexpensively.
Art

I would appreciate that you explain better what you are proposing.
Exactly how do you suggest I produce the gain or field pattern? My
plan is to switch in "real-time" between the antenna under test and
the reference antenna, thus eliminating as much as possible the
effects of QSB, conditions, etc.

73 - Kris, TF3KX

(Art Unwin KB9MZ) wrote in message om...
I may be missing something here, but why not produce a
gain or field pattern for each antenna on the same
signal, random or otherwise and overlay each pattern
and put in memory? ( cheap laptop and use a loop antenna
for reference )

In one of the early antenna compendiums ( ARRLL)
a Peter Dobbs of the U.K. supplies all the info
and program to get you onboard quickly and inexpensively.
Art