Gigahertz Solutions HF59B Bedienungsanleitung Seite 27

against ground influences one should "aim" about 10 degrees below
the emitting source one wants to measure. This is to avoid distortions
of the reading.
The upper edge of the foremost resonator is a good "aiming aid" for
the required angle. It does not matter if the angle gets a little too wide.
Our logarithmic periodic antenna, the "LogPer antenna", provides a
distinct division of the horizontal and vertical polarization plane. Also
the frequency response is exceptional. There is a patent pending for
its design.
(For professionals: For the technically rather difficult measurement of the vertical
polarization, it is significantly better shielded against the falsifying ground influences).
The missing directionality of standard telescope antennae is one of
the reasons why they are not suited for reliable HF measurements in
building biology EMR.
The readings from the instrument's display always reflect the integral
power density at the measurement location coming from the direction
the antenna is pointing at.
As the HF59B picks up frequencies below 700 MHz, it has no inte-
grated high pass filter. However the filter HP700 is available for ex-
ternal connection if needed, and is to be placed between the antenna
entry and the antenna cable.
In addition, the HF59B is able to capture numerous sources of radia-
tion in the lower HF band which are not pulsed (i.e. amplitude modu-
lated). By their nature these non-pulsed sources are not available for
audio analysis. That means you can get a significant reading on the
instrument without hearing any audio signal, which makes the inter-
pretation of the readings more difficult. To avoid this source of mis-
interpretation the instrument marks those "inaudible" signals by a
rattling tone, the loudness of which is in proportion to its share in the
total signal. The frequency of this marking is very low (16 Hertz). An
example of it can be found on our homepage. With the switch to the
right of the display in the "Pulse" position, these sources of radiation
as well as the corresponding rattling "marking" are blanked out.
For a quantitative measurement of frequencies below 700 MHz with
the HF59B, Gigahertz Solutions provides the active, horizontally iso-
tropic ultra broadband antenna UBB27_G3 responding to frequen-
cies from 27 MHz right up to more than 3.3 GHz.
LogPer or Omni-Antenna?
Depending on the task, either of the antennas have advantages
as well as disadvantages:
• For frequencies below 700 MHz the UBB27 antenna is the only op-
tion, as for geometrical reasons the LogPer antenna only starts at
700 MHz.
• For long term data logging in most cases the isotropic observations
make most sense: Again UBB27.
• For a quick survey of the total immission (that is: Total exposure to
radiation) the UBB also has clear advantages.
© Gigahertz Solutions GmbH
Made in Germany
Seite 25