Cobra 148 GTL 148-GTL User Manual
Product codes
148-GTL
Section I Introduction
FREQUENCY RANGE
The COBRA 148GTL 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 below.
The COBRA 148GTL 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 below.
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
27.055
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
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
20
27.205
The COBRA 148GTL 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.
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
operating instructions in this manual.
operating instructions in this manual.
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Section II Specifications
GENERAL
Channels
40 AM, 40 LSB, 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
-22° F to +122° F (-30° C to +50° C).
Microphone
Plug-in dynamic; with push-to-talk switch and
coiled cord.
coiled cord.
Input Voltage
13.8V DC nominal, 15.9V max., 11.7V min.
(positive or negative ground).
(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.
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).
(6 cm (H) x 20 cm (W) x 23.5 cm (D)).
Weight
5 lbs. (2.27 kg).
Antenna Conductor
UHF, S0239.
Semiconductors
3 field effect transistors, 45 transistors, 63 diodes,
6 integrated circuits, 1 two color light emitting
diode.
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
AM, 4 watts. 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.
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.
Transmit LED glows red when transmitter is in
operation.
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