Spectra Logic TAC/COM SERIES - Manual (Page 90)

Tac/Com Control Head Manual SM06 Rev. 4.10
As soon as the data is loaded into the radio, the next channel in the next block appears
(d32). Channels wrap around from highest to lowest, so that it is never necessary to
reverse direction to advance to any channel.
3.5.4
Summary of Subaudible Tones
Subaudible tones are sometimes used to screen unwanted transmissions on shared
frequencies. They are often referred to as PL Tones or Private Line Tones. The correct
name defined by the Telecommunications Industry Association (TIA) is Continuous
Tone Controlled Squelch System (CTCSS).
Tac/Com has stored a useful tone look-up table inside the help function. To view it, edit
a channel and move the editing cursor (flashing character) to the far right hand position
where the tone should be. Pressing HELP there will allow the CTCSS tone table to be
reviewed.
3.5.4.1
Methods of Tone Display
Over the years, many different codes have come into existence to describe these tone
sub-audible tone frequencies. They are listed below:
Tone Frequency (FREQ): - This is the TIA standard.
This is a frequency below 300 Hz that uniquely identifies the tone key that is
used to control the radio squelch (allows audio to be heard), or control a repeater
function. There are only three digits available on the control head for this data,
so any decimal fraction is omitted from the display (i.e., 103.5 Hz becomes 103).
Although not displayed, the correct frequency is still used.
EIA Codes (1-32):
This is a sequential number from 1-32 (or 38) that identifies the tone in order
from lowest (67.0 Hz) to highest (203.5 Hz or 250.3 Hz), as defined by the
Electronics Industry Alliance (EIA).
Wulfsberg Codes (WCODES):
These are sequential shifted OCTAL codes based on the thumbwheel design of
the C-1000 control. Because they are missing numbers ending in 0 & 9, they are
often confused with the straight sequential number for the EIA tones.
Motorola Codes (MCODES):
These are alphanumeric codes that seem largely random in assignment, but
often appear in the land mobile business if Motorola equipment is used.
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