F800 CIRCUIT DESCRIPTION
22 (25)
Uppgjord (även faktaansvarig om annan) -
Prepared (also subject responsible if other)
Nr
-
No.
KL/ECS/S/LT Magnus Lindahl
ECS/S/LT-96:5044
Dokansv/Godk -
Doc respons/Approved
Kontr
-
Checked
Datum
-
Date
Rev
File
KI/ECS/S/LTC
1996-06-06
A
965044.DOC
Modulation
Switch
Mod FM
Mod PM
From Outport
From AF circuits
FIG O: Block diagram modulation switch
The modulation sensitivity block is used to split the modulation signal into two different
signals. Due to different modulation sensitivity in the transmitter a mixture of FM and
PHASE modulation has to be used. The proportions between FM and PHASE
modulation depends on which frequency the transmitter is active on. The proportions
are controlled by the processor via outports Z13 and Z14. The processor sets the
switches in Z25 according to the operational frequency.
From the modulation sensitivity block there are two out signals, MOD FM for
frequency modulation and MOD PM for phase modulation. Both signals are connected
to the radio board. Max. deviation is set in the modulation sensitivity block. A fixed
proportion between FM and PHASE modulation is set, on the radio board