Codan Radio Communications VT-3-150-SN User Manual
Transmitter Main Board Instruction Manual
3-13
input to the transmitter to be used to gain access to the SUBTONE INPUT 2 which
connects to the PHASE MOD IN input of a modified synthesizer.
connects to the PHASE MOD IN input of a modified synthesizer.
• Make sure J13 and J16 are not installed.
Figure 3-1
Transmitter Audio Processor Low Frequency Modulation.
REMOVE
R47
R47
REPLACE WITH
10 uF
10 uF
+
SHORT TOP TWO PINS
MT3TXMNM7
MT-3 Transmitter Audio Processor (board version 43-911914 through 43-911916)
• Install jumpers: JU38Y, JU35Y
• Remove jumpers: JU27X, JU27Y, JU31, JU35X, JU37, JU38X
• Short pins P4-1 and P4-3 (or install J23) together with a short piece of 22 or 24 gauge
solid wire and solder (see figure 3-1). This allows the DIRECT MODULATION input
to the transmitter to be used to gain access to the SUBTONE INPUT 2 which connects to
the PHASE MOD IN input of a modified synthesizer.
to the transmitter to be used to gain access to the SUBTONE INPUT 2 which connects to
the PHASE MOD IN input of a modified synthesizer.
Note that the SUBTONE 2 input should not be used while this modification is in effect. Note also
that adjusting R44 has no effect on the deviation of the low frequency signal.
that adjusting R44 has no effect on the deviation of the low frequency signal.
MT-3 Transmitter Audio Processor (board version 43-911918)
• Contact factory for configuration.
3.11.3Synthesizer and Crystal Controlled Oscillator
Refer to the manual for the Oscillator used in your Transmitter for the required Low Frequency
Modulation modifications.
Modulation modifications.