EF JOHNSON 5100 ES II, Operating Manual, Page: 127 / 144

December 2006 5100 ES Model II/III Portable Radio Operating Manual 10-5
Secure Communication (Encryption)
10.2.5 Encryption Key Erase
A Key Erase menu item can be programmed that allows the user to permanently erase all
stored keys. If OTAR TEK and KEK keys are stored, all keys of both types are erased.
This function can be used to ensure that unauthorized encrypted calls can no longer be
placed or received by a radio.
10.2.6 Encryption Icon Operation
Basically, the encryption icon is on continuously whenever a secure call is received or
transmitted. Other operation is as follows:
• When a secure call is received on a digital channel in either the secure or clear mode,
this icon flashes.
• When a clear call is received on a digital channel in the secure mode, this icon is on
continuously.
• There is a programmable option on the Radio Wide screen to sound a beep whenever a
secure call is received on a clear channel.
10.3 Clear/Secure Strapping
10.3.1 Transmit Mode Options
The following transmit options are available when encryption is selected:
“Clear” - All calls are in the clear mode unless responding to a secure call. If the
response is then made within the delay time, it occurs in the secure mode.
“Secure” - All calls are made in the selected secure mode.
“Switched” - The mode is selected by the Clear/Secure switch. When the clear mode is
selected by this switch and a secure call is received, or vice versa, you will hear a beep.
Press the programmed option button to change to the appropriate mode.
If the channel has been strapped “Clear” and the option switch selects the “Secure” mode
on power up and a transmission is attempted, transmitting is disabled. Likewise, if the
channel is strapped “Secure” and the option switch selects the “Clear” mode on power up
and a transmission is attempted, the transmitter is disabled.
The radio can be programmed to ignore the “Clear” or “Secure” switch setting (“Ignore
Clear/Secure Switch When Strapped” selected on
Global screen). These preceding
indications then do not occur and transmissions always occur in the strapped mode.