Cobra Electronics 148.GTL.ST ユーザーズマニュアル
Section I Introduction
FREQUENCY RANGE
The COBRA 148 GTL ST transceiver represents one of the most advanced SSB/AM
two-way radios ever designed for use as a Class D station in the Citizens Radio
Service. This unit features advanced Phase Lock Loop (PLL) circuitry, which is used
in the AM mode and in the upper and lower single sideband modes, providing
complete coverage of all 40 channels shown belo w.
The COBRA 148 GTL ST transceiver represents one of the most advanced SSB/AM
two-way radios ever designed for use as a Class D station in the Citizens Radio
Service. This unit features advanced Phase Lock Loop (PLL) circuitry, which is used
in the AM mode and in the upper and lower single sideband modes, providing
complete coverage of all 40 channels shown belo w.
Channel
Channel Frequency
in MHz
1
26.965
2
26.975
3
26.985
4
27.005
5
27.015
6
27.025
7
27.035
8
27.005
9
27.065
10
27.075
11
27.085
12
27.105
13
27.115
14
27.125
15
27.135
16
27.155
17
27.165
18
27.175
19
27.185
20
27.205
The COBRA 148 GTL ST has a vastly superior receiver which includes an RF gain
control and noise blanker circuitry effective in both AM and SSB modes., and an
automatic noise limiter effective in the AM mode. The receiver also features
increased protection against cross modulation and strong adjacent channel signals.
To obtain maximum performance please read carefully the descriptions and oper-
ating instructions in this manual.
control and noise blanker circuitry effective in both AM and SSB modes., and an
automatic noise limiter effective in the AM mode. The receiver also features
increased protection against cross modulation and strong adjacent channel signals.
To obtain maximum performance please read carefully the descriptions and oper-
ating instructions in this manual.
Channel
Channel Frequency
in MHz
21
27.215
22
27.225
23
27.255
24
27.235
25
27.245
26
27.265
27
27.275
28
27.285
29
27.295
30
27.305
31
27.315
32
27.325
33
27.335
34
27.345
35
27.355
36
27.365
37
27.375
38
27.385
39
27.395
40
27.405
2
Serial No.
Date of Purchase
Dealer Name
Keep this manual for detailed information about your Cobra CB radio.
SAVE YOUR SALES RECEIPT, THE CARTON AND “PACKING” MATERIALS FOR
POSSIBLE FUTURE USE.
SAVE YOUR SALES RECEIPT, THE CARTON AND “PACKING” MATERIALS FOR
POSSIBLE FUTURE USE.
3
Section II Specifications
GENERAL
Channels
40 AM, 40LSB, 40 USB.
Frequency Range
26.965 to 27.405 MHz.
Frequency Control
Phase Lock Loop (PLL) synthesizer.
Frequency Tolerance
0.005%
Frequency Stability
0.001%
Operating Temperature Range
-30° C to + 50° C
Microphone
Plug-in dynamic; with push-to-talk switch
and coiled cord.
and coiled cord.
Input Voltage
13.8V DC nominal, 15.9V max., 11.7V
min. (positive or negative ground).
min. (positive or negative ground).
Current Drain
Transmit: AM full mod., 2.2A. SSB 12 watts
PEP output, 2A.
Receive: Squelched, 0.25A Maximum audio
output, 0.6A.
PEP output, 2A.
Receive: Squelched, 0.25A Maximum audio
output, 0.6A.
Size
2 3/8”(H) x 7 7/8”(W) x 9 1/4”(D).
Weight
5 lbs.
Antenna Conductor
UHF, S0239.
Semiconductors
3 field effect transistors, 45 transistors, 63
diodes, 6 integrated circuits, 1 two color light
emitting diode.
diodes, 6 integrated circuits, 1 two color light
emitting diode.
Meter (3-in-1)
Illuminated; indicates relative output power,
received signal strength, and SWR.
received signal strength, and SWR.
TRANSMITTER
Power Output
Power Output
AM, 4 watts.
SSB, 12 watts, PEP.
SSB, 12 watts, PEP.
Modulation
High-and low-level Class B, Amplitude
Modulation.
Modulation.
Intermodulation Distortion
SSB: 3rd order, more than -25 dB.
5th order, more than -35 dB.
5th order, more than -35 dB.
SSB Carrier Suppression
55 dB.
Unwanted Sideband
50 dB.
Frequency Response
AM and SSB; 300 to 2500 Hz.
Output Impedance
50 ohms, unbalanced
Output Indicators
Meter shows relative RF output power
and SWR. Transmit LED glows red when
transmitter is in operation.
and SWR. Transmit LED glows red when
transmitter is in operation.
148.GTL.ST.MANUAL 10/1/98 10:56 AM Page 5