User manual

Digitaler Hochfrequenz Analyser HF38B
© Gigahertz Solutions GmbH, D-90579 Langenzenn Revision 2.3 Page 8
Audio Frequency Analysis
Many different frequencies within the fre-
quency band between 800MHz and 2.5GHz
are being used by many different services.
The audio analysis of the modulated portion
of the RF signal helps to identify the source
of a given RF radiation.
First get the RF analyzer ready for testing,
following the instructions in the relevant sec-
tion. For audio analysis, simply turn the vol-
ume of the speaker at the upper right knob of
the case all the way to the left („-„) because if
you are switching to audio analysis while
high field strength levels are prevalent rather
high volumes can be generated quite sud-
denly. This, of course, is especially true for
measurements that are to be taken without
audio analysis. The knob is not fastened with
glue to prevent overwinding. However, if you
should by accident turn the knob too far,
simply turn it back again.
Set the „Betrieb (On)“ knob at
. Sounds
and signals are very difficult to describe in
writing. The best way to learn the signals is
to approach known RF sources very closely
and listen to their specific signal patterns.
Without detailed knowledge, the character-
istic signal patterns of the following RF
sources can be easily identified: 2.4-GHz
telephones (base station and handset) as
well as cellular phones, whose signal pat-
terns can be divided into „during the phone
call“, „stand-by mode“ and especially the
„establishing of a connection“. The typical
signal patterns of a cellular phone base sta-
tion can also be identified this way. For com-
parison reasons you are well advised to take
measurements during high-traffic times and
some time at night in order to familiarize
yourself with the different noises.
The volume can be controlled with the „Laut-
stärke (speaker)“ knob. Note: The power
consumption of the speaker is directly pro-
portional to the volume.
Battery
The RF analyzer requires a high-quality 9-Volt
square battery. Due to its rather high power
consumption, at least an alkali-manganese
battery should be used.
Because rechargeable 9-Volt square batter-
ies have a quite low capacity, they are not
recommended. The same applies to cheap
zinc-coal batteries. On principle, of course,
such batteries could also be used, but their
operation time will be considerably shorter.
The RF analyzer comes equipped with a high
quality brand name alkali-manganese bat-
tery.
Changing Batteries
The battery compartment is located on the
backside of the case. To open, press down
on the fluted arrow and slide off the battery
cover towards the bottom end of the RF ana-
lyzer. The inserted piece of foam provides a
snug fit for the battery to prevent it from rat-
tling. The sliding back of the cover should
always require some slight pressure.
Auto-Power-Off
This function conserves energy and extends
the total operating time.
1. In case you forgot to turn off the RF ana-
lyzer or it was accidentally turned on during
transport, it will be automatically shut off af-
ter 40 minutes of continuous use.
2. When in the center of the display „low
batt.“ appears vertically in-between the dig-
its, the RF analyzer will be turned off after
only 3 min in order to avoid unreliable meas-
urements.