Chapter 3. Remote Commands; Introduction; Rf Input Level; Attenuator Control - Comtech EF Data LPOD PS-1 Installation And Operation Manual

Chapter 3. REMOTE COMMANDS

3.1

Introduction

This section describes the operating features of the LPOD C-/Ku-Band Outdoor Amplifier /
Block Up Converter (BUC). A few key parameters and procedures are summarized, followed by
detailed instructions of remote control communication commands.
3.1.1

RF Input Level

The required RF input level to reach the full rated output power of the SSPA is determined by the
individual amplifier maximum gain and power rating. For example, if the test data of an SSPA rated
for 250W (54 dBm) indicated a gain of 75 dB, then a signal of 54 dBm – 75 dB = -21 dBm would
approximately give the rated output power. Increasing input power beyond this level would result in
an output signal with increasingly higher levels of distortion. Of course, if the LPOD attenuation
control is utilized, a higher level input signal level can be accommodated. The maximum input level
should never exceed 15dBm, or permanent damage to the unit may occur.
3.1.2

Attenuator Control

The LPOD gain can be attenuated over its specified range by exercising the
details for the format of this command are found later in this chapter.
3.1.3

Mute Control

The LPOD may be muted via software or discrete control. Exercising the
"software" mute the unit. The LPOD also may be "hardware" muted by pulling Pin S on the Com
1 / Discrete control connector (J6) to ground (See Chapter 2. SYSTEM CONNECTIONS and
OPERATION).
The Mute command provides over 75 dB of RF on/off isolation. However, the Mute command
only turns off the first few low power stages of the amplifier, the high power stages remain on.
By allowing the higher power transistors to stay on, the LPOD remains in more thermally stable
state should the mute condition be removed.
3–1
ATT command. The
command will
MUT=1