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Coded / clear using positive mode control keying – CTI Products TSAM Transmitter Steering & Audio Matrix User Manual

Page 49

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TSAM Installation and Maintenance Rev. 2.10

Chapter 5

CTI Products, Inc.

Setting Programmable Options

41

5.5.2.1

Coded / Clear using Positive Mode Control Keying

This option works with Main (Steered) system and the Secondary system (if used).

The TSAM can be programmed to generate two function tones in a tone control sequence. This is called
positive mode control (PMC). PMC is used in some Motorola radio systems for controlling encrypted and
clear mode keying. The additional function tone is typically set for:

• Clear TX

1050 Hz

• Coded TX

1150 Hz

Special PMC Frequency Change Tone:
The PMC tone is also used in specially configured base stations for secondary channel frequency change
operation. This control tone is the Frequency Change Tone, (2050 Hz). Using the Frequency Change
Tone, the TSAM switches remote base stations from frequency to frequency without keying the base
station. This prevents a base station being switched back to the Main channel from momentarily keying
during an ongoing transmission, which can happen with conventional tone control schemes. This is a
very special function found only on specially modified radios used in Denmark.

The PMC tone sequence sent to the base station is:

• HLGT
• PMC Tone
• Standard Function Tone
• LLGT + Voice Audio

Select Coded (Encrypted) TX operation:
P Positive Mode Control (PMC - Dual function tone)
Supports Main & Secondary
S Single Function Tone Coded Control
Supports Main Only
F1=Clear Keying; FCoded=Coded Keying
N No Coded Support
(P/S/N)? --> (N) N : P
Clear Key FT (Hz) = (1050) 1050 : 1050
Coded Key FT (Hz) = (1150) 1150 : 1150
Frequency Change FT (Hz) = (2050) 2050 : 2050

To edit the PMC options, press P at the menu prompt and enter the desired control tones.

If you do not have specially modified base stations that use the Frequency Change tone, program it
the same as the HLGT (typically 2175 Hz).

The PMC tone is controlled by the Console 1 & 2 Coded/Clear signals.