RadioBanter - View Single Post

April 26th 05, 08:16 AM

wrote:
Rather than deflect away from Reg's needs may I go back to the
"compared to a dipole" statement which Richard keeps brushing off. If
the gains are different then the angle for max radiation is different
and if you do not take this into account by searching for the
individual point of maximum gain position then the the measurements are
in total error. To put antennas at the same height and then measuring
at the same stationary
point for receive,
switching back and forth
is not a true comparison because of the different elevation angles.

I don't think Richard is attempting to deny that.

His tests were not intended to measure the gain of the antenna. They
were intended to answer a much more practical question: "How much
stronger is the signal from the curtain array, as delivered into the BC
target area, compared with using a dipole?" That's what the station
owners wanted to know, and they specifically wanted that answer to
include all the variables of antenna patterns and ionospheric
propagation.

As you have correctly pointed out, in any environment except free space,
that number is not the same as the antenna gain in dBd. Anybody who has
thought about it is aware of the problem, and that clearly includes
Richard.

Everybody agrees with you, so you can stop banging on that open door.

--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek