Wavetek 3HRV Spécifications télécharger pdf (Page 24)

4-1

SECTION 4 OPERATION - HOW TO USE THE 3HRV HEADEND

REVERSE SWEEP RECEIVER

4.1 INTRODUCTION

This section provides detailed operation of the 3HRV. Included are

detailed descriptions of the various displays of the selected modes of

operation.

4.1.1 Wavetek Stealth Reverse Sweep Concept

With the reverse sweep option, a transmitter is built into the hand-

held sweep receiver. The headend reverse sweep receiver (3HRV) is

set up to receive the reverse sweep sent from the field. When a

reverse sweep is activated from a field test point, the 3HRV receives

the telemetry signal that indicates which receiver is sending the

sweep. The headend receiver measures the sweep, and sends the

results, along with the serial number of the sending receiver via its

telemetry signal to the field. The field receiver with the tagged serial

number then displays the sweep response as measured in the headend

on its LCD. Up to 10 receivers at a time can perform reverse sweep-

ing. If additional receivers attempt to sweep a message is displayed.

4.1.2 Basic Reverse Sweep Procedure

Sweeping the reverse path is a little different from sweeping the

forward path. Because the system is designed with appropriate spacing

for the forward high frequency range, the reverse path may not require

amplification at each station. The lower frequencies aren't attenuated

in cable as much as the higher frequencies. In sweeping the forward

path the amplifier is aligned such that its output is within certain

limits (the amplifier compensates for the cable behind it). However in

sweeping the reverse path the amplifier is aligned such that the

response at the headend is within certain limits from this amplifier

alignment point. So, in the reverse path the amplifier compensates for

loss characteristics in the cable in front of it.

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Wavetek 3HRV Spécifications Page 24