Section 3. Operation
3-3
Carrier Controlled Repeat (Open Repeater)
The Model 38 can be programmed to activate based on just carrier. In this mode the Model
38 will provide simultaneous tone and open repeater operation; users that have CTCSS or
Digital Squelch encode operate normally, users that have no encode repeat also. This allows
a mix of CTCSS tone users with open repeat capability and is ideal when adding tone users
to an existing open repeater.
To enable carrier (COR) for repeat, a user number is identified as the “CARRIER” repeat
user. This allows all standard user-programmable attributes to apply to open repeat,
including; enable/disable for the carrier user, CTCSS or digital code encoding, airtime
accumulation, station ID, etc. If the COR user number is set to “0”, the carrier repeat
function is disabled.
Reserved Users
If a user is marked as “Reserved,” the repeat audio will be squelched and a beep tone sent in
place of voice communications. A chirp tone will be sent when the user unkeys to indicate
reserve mode. This mode allows the system manager to reserve CTCSS tones and DCS codes
for seasonal users, or to temporarily prevent communications for a delinquent account.
WHAT HAPPENS WHEN A MOBILE UNKEYS
When a mobile unkeys, CTCSS tone or DCS code is no longer detected, the Model 38 will
do the following:
Anti-Kerchunker Filter
The anti-kerchunker filter cancels the transmit hold time and drops the repeater
immediately if a mobile transmission is less than the programmed “anti-kerchunk”
time. This serves two main purposes:
•
It will discourage users from “kerchunking” the repeater to death.
•
It will make the repeater co-exist better on shared-channels. When a lot of CTCSS
tones are enabled on a single channel, it’s not uncommon for voice falsing of
active CTCSS tones on a co-channel repeater to occur. This is because a human
voice often contains frequencies in the CTCSS band. A radio user could be
talking and cause a co-channel repeater to key up over the conversation. When the
repeater transmit hold time is greater than about a second, this causes major
interference to the voice communication. With the anti-kerchunker filter enabled,
the repeater will key ONLY for the duration that the voice simulates CTCSS, not
the entire transmit hold time. The anti-kerchunker filter is disabled by
programming the time to zero.
Courtesy Tone
If the courtesy tone is enabled for the user group, a short beep will be sent. The beep
frequency may be set from 400 to 4000 Hz (default setting is 1000 Hz). A system
programmable setting called “tailbips” can be enabled to cause the courtesy tone to
