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(1) Make it clear what to measure. Like the frequency, bandwidth and
modulation method of the tested signal. For example, modulated stereo
broadcasting, modulation method is FM and the typical bandwidth is 250kHz.
Different measuring purposes may be corresponding to different sets of
parameters. As for modulated broadcasting, nominal bandwidth should be
adpoted to ensure the precision of field intensity measurement. Or simply set
it according to the testing standards, which typically is 200kHz or 250kHz. A
wrong bandwidth selection results in either a smaller-than-actual field
strength reading due to the fact that the energy outside the bandwidth hasn't
been detected, or a higher-than-actual field strength reading for taking the
unwanted interference into account.
In scenario where monitoring the audio is the main purpose while the field
strength is just for a glimpse, bandwidth could be narrowed appropriately, like
120kHz or 150kHz. As for monitoring, the priority is to hear the content clearly.
By selecting a minimum bandwidth in which no obvious distortion has
occured, noise can be reduced and an ideal monitoring effect can be achieved.
(2) Select desired port and connect the tested antenna. To acquire a
precise field strength, an antenna with known gain must be used. As for
direction finding, the utilized antenna should come with either a distinct
directionality, or a sharp null point. Lastly, if the user just wants to monitor the
audio, just select the antenna following heart.
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