Cobra Electronics HH36ST Section I Introduction, Section II Specifications, Frequency Range

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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.

Channel

Channel Frequency

Channel

Channel Frequency

 

in MHz

 

in MHz

1

26.965

21

27.215

2

26.975

22

27.225

3

26.985

23

27.255

4

27.005

24

27.235

5

27.015

25

27.245

6

27.025

26

27.265

7

27.035

27

27.275

8

27.055

28

27.285

9

27.065

29

27.295

10

27.075

30

27.305

 

 

 

 

11

27.085

31

27.315

12

27.105

32

27.325

13

27.115

33

27.335

14

27.125

34

27.345

15

27.135

35

27.355

16

27.155

36

27.365

17

27.165

37

27.375

18

27.175

38

27.385

19

27.185

39

27.395

20

27.205

40

27.405

 

 

 

 

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.

To obtain maximum performance please read carefully the descriptions and 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.

 

 

Input Voltage

13.8V DC nominal, 15.9V max., 11.7V 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.

 

 

Size

2 3/

8

”(H) x 7 7/

”(W) x 9

1/ ”(D).

 

 

 

8

4

 

(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.

 

 

Meter (3-in-1)

Illuminated; indicates relative output power,

 

received signal strength, and SWR.

TRANSMITTER

 

 

 

 

 

Power Output

AM, 4 watts. SSB, 12 watts, PEP.

Modulation

High-and low-level Class B, Amplitude

 

Modulation.

 

 

Intermodulation Distortion

SSB: 3rd order, more than -25 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.

 

 

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Contents Citizens Band SSB/AM 2-WAY Mobile Radio Contents If You Think You Need ServiceGeneral Section II SpecificationsSection I Introduction Frequency RangeLocation Section III InstallationReceiver PA SystemAntenna Tuning the Antenna for Optimum SWRAntennas with adjustable screws set screws Ignition Noise InterferencePublic Address Controls and IndicatorsSection IV Operation External SpeakerSection IV Operation Receiving SSB Signals Indicator FunctionsOperating Procedure to Receive Operating Procedure to TransmitWire MIC Cable Alternate Microphones and InstallationSection IV Operation Code Meaning Section V Maintenance and AdjustmentSection VI Appendix CodePermitted Example Message FEW Rules That should be ObeyedHOW Your CB can Serve YOU USE Channel 9 for Emergency Messages onlyRadio Bidireccional Móvil SSB/AM DE Banda Ciudadana Índice Página Si cree que requiere servicioGenerales Sección I Introducción Sección II EspecificacionesIntervalo DE Frecuencias Canal Frecuencia del canalLugar Sección III InstalaciónReceptor Sistema DE AltavozNota Sección III Instalación continuaciónInterferencia POR Ruido DEL Encendido AntenaFunciones DE Control Sección IV OperaciónAltoparlante Externo Controles E IndicadoresSección IV Operación continuación Recepción DE Señales SSB Funciones DE LOS IndicadoresProcedimiento Operativo Para Recibir Procedimiento Operativo Para TransmitirCable DE Micrófono DE 4 Hilos Micrófonos Alternativos E InstalaciónSección IV Operación continuación Código Significado Sección V Mantenimiento y ajustesSección VI Apéndice CódigoUtilice EL Canal 9 Únicamente Para Mensajes DE Emergencia Sección VI Apéndice continuaciónReglas QUE Debe Obedecer Aplicaciones DEL Radio CB