65 Aleksandar Stamboliyski Str., 8000 Bourgas, Bulgaria
Tel: +359 56 820027, Fax: +359 56 836700
E-mail: [email protected] ,Web: www.devabroadcast.com
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Co-channel Interface
In many populated areas, there is not enough space in the radio spectrum and stations might
be jam-packed. Poor frequency planning may also result in the mutual interface between the
broadcasting stations.
The inherent broad bandwidth of DB7000 re-broadcast receiver is vulnerable from stations
working on the nearby frequencies, where signal strength will be the most important factor – the
stronger the interfering station, the stronger the interference effect.
We recommend you to observe the independent positive and negative deviation readings in
order to identify adjacent channel interference. If the positive deviation is higher than the negative
one, interference from a strong station above the monitored frequency would be indicated and
vice–versa. For example, the negative deviation can probably be trusted as an indication of total
carrier modulation, though this should be confirmed in free of interference RF environment.
Anyhow, the program deviation should be fairly symmetrical about the carrier frequency. Using
the built-in Attenuator can be of some help, but the usage of an outdoors directional antenna could
improve the situation with unwanted adjacent working stations. Other solutions include a band-
pass filter at the primary frequency or a trap at the interfering frequency.
