Tyco Electronics MM23016 MM23016, Rev. C , 8.8.5 Private Operation

MM23016, Rev. C

• If Private mode is disabled and a private call is received, the Reply transmission will be in Private

mode if the transmission is made during the scan hangtime. If the reply transmission occurs after the

scan hangtime, the transmission will be in Clear mode.

When operating on a group or channel programmed for private mode, all transmissions will be private

transmissions and the radio will receive clear and private signals. If the selected group or channel is

programmed for auto-select capability, the mode can be toggled between private and clear with the OPT

or OPTION button. Radios programmed for forced private operation do not allow a change of the

transmit mode; therefore, the OPT or OPTION has no effect.

8.8.4.1 Displaying the Currently Used Cryptographic Key Number

To display the cryptographic key currently in use for either the system encryption key (for special call

such as individual, phone, all, agency or fleet) or the group/channel key (for group or conventional calls),

perform the following procedure (Not Available on Conventional radios):

1. Press the MENU button.

2. Use to select DISP KEY. Then press the MENU button.

3. Then use to toggle between displaying the system key or the group/channel key.

Table 8-4: Current Cryptographic Key Display

ENCRYPTION KEY

DISPLAYED MESSAGE DISPLAYED

System "SYS KEY"

"KEY = 1"

Group/Channel "GRP KEY"/"CHN KEY"

"KEY = 2"/KEY = 2"

8.8.4.2 Key Zero

All cryptographic keys can be zeroed (erased from radio memory) by pressing the CLR button (System

Model) or CLEAR (Scan Model) and while still pressing this button, press and hold the OPT button

(System Model) or OPTION (Scan Model). Press both buttons for 2 seconds. A series of warning beeps

will begin at the start of this 2-second period and then switch to a solid tone after the keys have been

zeroed. The display will indicate KEY ZERO.

If the cryptographic key(s) are zeroed, one or more key s must be transferred fro m the Key Loader into the

radio before private communications can continue. (Refer to Key Manager TQS3416 Administration and

Software Release Notes for further information.)

8.8.5.1 Receiving an Encrypted Call

When receiving, the radio automatically switches between clear or private operation. If the transmission

being received is an encrypted transmission, it will be decrypted, the receiver will unsquelch and the

message will be heard in the speaker. The selected group or channel must be programmed for private

operation and the correct cryptographic key must be loaded into the radio for this to occur.