Cobra Electronics HH36ST User Manual

Page 4

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RECEIVER

Sensitivity

SSB: 0.25 µV for 10dB (S+N)/N at greater than

1/2-watt of audio output.
AM: 0.5 µV for 10 dB (S+N)/ at greater than 1/2-
watt of audio output.

Selectivity

AM: 6dB @ 3 KHz, 50 dB @ 9 KHz.

SSB: 6 dB @ 1.1 KHz, 60 dB @ 2.3 KHz.

Image Rejection

More than 65 dB.

IF Frequency

AM: 7.8 MHz 1st IF, 455 KHz 2nd IF.

SSB: 7.8 MHz.

Adjacent-Channel Rejection

60 dB AM & 70 dB SSB.

AM and SSB RF Gain Control

40 dB adjustable for optimum signal reception.

Automatic Gain Control (AGC)

Less than 10 dB change in audio output for

inputs from 10 to 100,000 microvolts.

Squelch

Adjustable; threshold less than 0.25 µV.

ANL

Switchable.

Noise Blanker

RF type, effective on AM and SSB.

Voice Lock Range

±2.5 KHz.

Audio Output Power

4 watts into 8 ohms.

Frequency Response

300 to 2500 Hz.

Built-in Speaker

4 ohms, round.

External Speaker (Not Supplied)

8 ohms; disables internal speaker when

connected.

PA SYSTEM

Power Output

4 watts into external speaker.

External Speaker for PA

8 ohms.

(Not Supplied)

(SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE)

4

Section III Installation

LOCATION

Plan the location of the transceiver and microphone bracket before starting the
installation. Select a location that is convenient for operation and does not
interfere with the driver or passengers in the vehicle. In automobiles, the
transceiver is usually mounted below the dash panel, with the microphone
bracket beside it.

MOUNTING THE CONNECTION

The COBRA 148GTL is supplied with a universal mounting bracket. When
mounting the bracket and radio to your car, make sure it is mechanically strong.
Also provide a good electrical connection to the chassis of the vehicle. Proceed as
follows to mount the transceiver:

1. After you have determined the most convenient location in your vehicle, hold

the COBRA 148GTL with mounting bracket in the exact location desired. If
nothing will interfere with mounting it in the desired position, remove the
mounting bolts. Before drilling the holes, make sure nothing will interfere with
the installation of the mounting bolts.

2. Connect the antenna cable plug to the standard receptacle on the rear panel.

Most CB antennas are terminated with a type PL-259 plug and mate with the
receptacle.

3. Connect the red DC power input wire (with the fuse) to +13.8V DC. This wire

extends from the rear panel. In automobile installation, +13.8V DC is usually
obtained from the accessory contact on the ignition switch. This prevents the
set being left on accidentally when the driver leaves the car and also permits
operating the unit without the engine running. Locate the accessory contact on
most ignition switches by tracing the power wire from the AM broadcast
receiver in the car.

4. Connect the black lead to -13.8V DC. This is usually the chassis of the car. Any

convenient location with good electrical contact (remove paint) may be used.

5. Mount the microphone bracket on either side of the transceiver, using the two

screws supplied. When mounting in an automobile, place the bracket under
the dash so the microphone is readily accessible.

5

Section II Specifications (Cont.)

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