MODEL 38A Repeater Panel
The Zetron Model38 Repeater Panel is
a flexible, remotely programmable repeater tone panel that converts
any station capable of duplex operation into a full featured
repeater. The Model38 is an ideal replacement for older
card-per-user tone panels, eliminating time consuming trips to
remote repeater sites as well as the high cost of individual tone
cards for each customer.
ToneLock, a Zetron exclusive,
eliminates repeater talkdown or dropout resulting from weak, fading
signals, high modulation levels, or poorly processed mobile
transmitter audio. A ToneLock equipped Model38 will recognize a
CTCSS tone or digital code with a receiver quieting level of 3 dB
SINAD. Typical programmable tone panels require a minimum of 8 dB
SINAD before reliable tone decoding occurs. The Model 38 can even
out perform traditional reed type decoders. The Model38 will not
false on adjacent tones, even when receiving CTCSS tones transmitted
with a phase reversal.
CUSTOMER MANAGEMENT FEATURES
The Airtime Keeper keeps track of all
system use for customer billing purposes. Airtime totals can be
retrieved by Morse code, by a Model8B Programmer/Timekeeper, or by
using a pair of modems and any RS-232 equipped terminal or computer.
Airtime data may also be retrieved with a directly connected Model8B
Programmer/Timekeeper or an RS-232 equipped terminal, or computer.
The Prepaid Airtime feature allows a customer to purchase a block of airtime in advance. As the customer uses the repeater, the amount of unused airtime decreases. When the supply of prepaid airtime is nearly gone, the customer hears a warning tone whenever a radio unkeys. If the customer does not purchase additional airtime, the customer�s tone reverts to reserved status when the original block of time runs out. This permits the system operator to pre-bill problem customers.
The Privacy Mode feature prevents users on different CTCSS tones or digital codes from assuming control of the repeater until after the transmitter hold-time expires. This reduces or eliminates repeater barge-ins. The Anti-Kerchunker Filter cancels the transmit hold-time and drops the repeater transmitter immediately if a mobile transmission lasts less than one second. This prevents prolonged repeater transmissions due to momentary mobile key-ups. The Stuck Mic feature identifies which radio fleet has locked up the repeater. When the repeater times out, the Model38 transmits a two-digit DTMF sequence corresponding to the programmed user number. This helps identify the source of intentional or accidental repeater jamming.
PROGRAMMING AND CONTROL
The Model 38 Repeater Panel can be interrogated and programmed from a DTMF radio, from a Zetron Model 8B, or from a computer that is either connected directly or operating through telephone or packet modems (see diagram). Programming by computer is easy because the Model 38 puts questions and lists of choices on-screen. Programming via the built-in RS-232 port does not require taking the unit out of service. This means your repeater stays on the air, even as customers are added or removed from the system.
|Frequency Range||67 to 250.3 Hz|
|38 CTCSS/22 DCS
No. of Tones
No. of Digital Codes
|50 CTCSS/18 DCS
No. of Tones
No. of Digital Codes
|Input Impedance||100K-ohm AC coupled. For connection to unsquelched discriminator audio|
0.0 to 3.0 V p-p, selectable
Flat or de-emphasized
Less than 1%
Less than 1K-ohm AC coupled
|Morse ID Freq.||1200 Hz; adjustable �800 Hz|
|Beep Frequency||1000 Hz; adjustable 400 to 3000 Hz|
|DTMF Encoder||Standard DTMF tones|
|Connections||Discriminator; Push-to-Talk; CTCSS, Output; Repeat Audio; Alarm Input/Remote PTT Input; Power; Ground|
|Connector Type||Detachable screw terminal|
|Adjustments||Four adjustments from rear panel: Input Level; CTCSS Encode Level; Output Level; Squelch|
|Indicators||Power; Carrier; Decode; Encode; Transmit; DTMF|
|Local Prog. Port||Front-panel audio jack for local DTMF programmer|
|Serial Data Port
Tx data, Rx data, common/gnd
Follows XON/XOFF protocol
Selectable: 150; 300; 600; 1200; 2400; 4800
|Rear Switches||Audio Input Level
(high/low); Audio Input (flat/de-emphasized);
CTCSS Output Level (high/low);
CTCSS Output (flat/de-emphasized);
Audio Output Level (high/low); COR (internal/external); COR Polarity (positive/negative)
|Repeat Audio||Flat or de-emphasized|
|Long Digit Reset||A single DTMF digit
received by the
Model 38 for 15 seconds may be used to reset the Model 38 remotely.
|ToneLock||ToneLock decodes a CTCSS tone with a receiver quieting level of 3 dB SINAD after initial acquisition|
|COR Input Range||Adjustable threshold of
0 to 7VDC.
Level must change by at least 1 volt between carrier and no carrier conditions
|Squelch Tail Elimination||Model 38 decodes mobile�s reverse phase burst, or digital turnoff code|
|Current Consumption||350 mA at 13.8VDC|
|Oper. Voltage Range||11VDC to 15.0VDC|
|Rack-Mount Size||1.7" x 19" x 4.8"|
|Operating Temp||0 to 65 degrees C.|
WISCO International, Inc. -
MIAMI, FL U.S.A.
Fax: E-mail: firstname.lastname@example.org