DRAKE HCP2550A Manual de instrucciones - Página 8

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Rear Panel Controls and Connections

MADE IN THE U.S.A. BY

RF OUTPUT

FCC OFFSET

EAS IF IN

R1 – RF OUTPUT Connector

This is the converted channel output.

R2 - FCC OFFSET Switch

The HCP2550A synthesizer has been programmed to

comply with FCC requirements for offsets on cable

channel frequencies assigned to aviation and navigation

communications with the 'FCC OFFSET' switch set to the

"+" position. With the switch in the "+" position, the

HCP2550A will automatically offset the visual carrier

either +12.5 kHz or +25 kHz above the channel frequency

on required channels as listed in Table 2 – OUTPUT

CHANNEL included in this manual. Be certain of the

permissible operating frequency if this switch is to be

set to the "0" position since NO offset will be applied to

any channel. Similarly, setting the switch to the "-"

position forces the offset to a programmed -12.5 kHz or

-25 kHz as required. The normal setting for this switch

is in the "+" position.

R3 – EAS IF IN Connector

This is an alternate composite IF intended for the

Emergency Alert System (EAS) signals as defined by Part

11 of the FCC requirements. This input is manually

activated by setting the 'EAS' switch (R9) to the 'Manual'

position and grounding the

EAS

automatically activated by setting the 'EAS' switch to the

'AUTO' position. When the unit is strapped for automatic

switching to the EAS input, switching will occur for levels

of the 45.75 MHz RF signal exceeding +20 dBmV at the

'EAS IF IN' connector. The nominal operating EAS

composite IF input level is +28 dBmV. Note that the

composite signal must have the visual carrier at

45.75 MHz and the aural carrier at 41.25 MHz.

R4 – COMPOSITE IF IN Connector

This is the composite IF input to the output channel

circuits. The composite IF has both the aural and visual

IF combined. This connection is normally cabled directly

to the "COMPOSITE IF OUT" connector (see Item R5).

This external loop allows the use of accessories such as

scramblers or alternate video sources. Note that

accessory equipment must also have the visual carrier at

45.75 MHz and the aural carrier at 41.25 MHz. Both input

carriers must be at their nominally specified levels.

COMPOSITE IF

EAS

OUT

IF LOOP

screw terminal (R6), or is

R10

CAUTION:

- RISK

SIGNAL

OF FIRE - REPLACE

STRENGTH

EAS

PILOT

FUSE AS MARKED

AFTER DISCONNECTING

AUTO

OFF

UNIT FROM AC LINE.

ATTENTION:

- RISQUE D'INCENDIE -

MANUAL

REMPLACEZ FUSIBLE DU

TYPE INDIQUE APRES

DEBRANCHER DU SECTEUR.

Figure 2

R5 – COMPOSITE IF OUT Connector

This is the composite IF output from the IF circuits. The

composite IF provides a vestigial sideband filtered visual

carrier at 45.75 MHz (plus or minus any input signal

offset) combined with a level controlled aural carrier at

41.25 MHz (plus or minus any input signal offset). This

connection is normally cabled directly to the

"COMPOSITE IF IN" connector (see Item R4).

R6 –

Terminal

With the "EAS" switch (see Item R9) set to the `MANUAL'

position, connect this screw terminal to ground for manual

activation of the EAS input.

R7 – GROUND Terminal

This screw terminal connects to circuit ground.

R8 – SIGNAL STRENGTH Terminal

This screw terminal provides monitoring the received

signal strength by supplying a 0 to +12 VDC output that is

proportional to the relative signal strength. Increasing

signal strength levels produce an increasingly positive

voltage at this terminal.

R9 – EAS Switch

Set this switch to the 'AUTO' position for automatic EAS

activation for signal levels greater than +20 dBmV at the

"EAS IF IN" connector. With this switch set to the

'MANUAL' position, ground the "

R6) for manual activation of the EAS input.

R10 – PILOT Threshold Switch

Set this switch to the 'ON' position to enable the front

panel "PILOT THRESHOLD" Control (see Item F8 – "Front

Panel Controls and Indicators" section of this manual).

R11 – RF INPUT Connector

This is the input to the channel processor circuits for all

signals with video carrier frequencies in the range of 54

through 806 MHz.

R12 – FUSE Holder

Always replace this fuse with one of the same type and

rating: ½ Amp, 250 V, SLO-BLO, 5 x 20 mm type.

R13 – LINE CORD Receptacle

Accepts a 3-wire detachable power cord. Connect to a

115 VAC ( 10%), 60 Hz source.

R11

R12

R13

FUSE

115 VAC, 60 Hz

1 / 2 AMP, 250 V

SLO

BLO

RF INPUT

SERIAL #

EAS

" terminal (see Item

30 WATTS