Encoder Installation
32 025-9567E
Deviation
The encoder can continuously generate a sequence of three tones for use in determining the
proper tone output level and the proper pre-emphasis or de-emphasis. The deviation test
consists of a 500 Hz tone, followed by a 1000 Hz tone, followed by a 2000 Hz tone, each
tone lasting four seconds. This sequence is repeated until the encoder RESET key is pressed.
When RESET is pressed, the encoder will begin its operation as if power had been removed
and reapplied (power-on self-test will begin).
The deviation test is invoked from the encoder keypad by holding down the RESET key then
holding down the “1” key and releasing the
RESET key. When the encoder display shows the
word “
PrOG” the “1” key may be released at which time the display will change to “1 __”.
Now key-in the number 41 and the deviation test will begin. From a PC the deviation test is
invoked by typing a “P”, “1”, then “41”. The deviation test is halted from a PC by holding
the “break” key down for 2 seconds. While the tones are being generated for the deviation
test, the encoder display will show the word “tOnE”.
Verification Mode
Often times it is desirable to measure the encoding tones, one at a time, in a simulated
transmission but without keying the transmitter and sending the tones over the air. The
verification mode, when enabled, will prevent the Push-To-Talk from ever closing. In
addition, each individual encoding tone will pause for verification at the audio output until a
keyboard key is pressed. The tone sequences will progress to the next tone only when a key
is momentarily pressed. The gaps between tones, which generate no tone, also pause until a
key is pressed. When verifying a stack of calls, the current call begin generated will have its
number shown in the encoder display. Holding two keys down simultaneously will cause the
tones to rapidly progress so that a particular call in a stack can be reached quickly. Note that
the tones generated while in verify mode may not be as accurate as when they are being sent
in normal operation. The tones may be off by as much as 1% at the higher frequencies. The
verification mode, therefore, is more for programming verification rather that tone accuracy
verification.
The verification mode is enabled or disabled via the encoder keypad by holding down the
RESET key then holding down the “1” key and releasing the RESET key. When the encoder
shows the word “
PrOG” the “1” key may be released at which time the display will change to
“1 __”. To enable the verification mode key-in the number “51”. To disable the verification
mode key-in the number “50”. After keying the two-digit number the encoder will return to
the normal idle state
From a CRT the verification mode is enabled by typing a “P”, “1”, then “51”. The
verification mode is disabled by typing a “P”, “1”, then “50”. After typing the number, press
the “break” key for 2 seconds and the encoder will return to the normal idle state.
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