Interference By The Transmitter Of Your Station; Countermeasure - JRC NDR-91 Instruction Manual

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By removing the antenna, connecting the receiver to other antenna, using the other
power supply line and moving the installation place, the route can be found.
(3) Countermeasure
Basically, the countermeasure must be taken at the noise source side. In any cases, all
equipments must be grounded. If the equipment is surely grounded by means of the
wide copper board, the noise interference may be resolved. Also, a line filter which
suppresses the HF noise is very effective at the power supply wire. After finding the
noise source and noise route, please examine the trouble and ask the countermeasure to
the maker or sales agent of that equipment which is of the noise source.
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6.3.4 Interference by the transmitter of your station
At the station where many radio equipments are installed, when some transmitter
transmits the radio wave, the receiver may catch the noise in spite of that the frequency is
different. It is a rule that the receiver is muted by using -BK signal while transmitting.
But when performing the simultaneous transmission and reception because of the duplex
communication, it is important to separate transmitting antenna and receiving antenna as
far as possible. Even though the antennas are located at same distance from the transmitting
antenna, the receiving antenna located not in parallel to the transmitting antenna has less
interference.
Generally, the interference depends on the difference between the receiving frequency
and transmitting frequency. The bigger the difference is, the less the interference is. Also,
the degree of the interference depends on the performance of the antenna multi-coupler,
protective diode, etc.
N o i s e s o u r c e
T h e n o i s e g o e s t o t h e
v i a t h e p o w e r c a b l e .
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