Cisco Cisco 1 GHz GainMaker Amplifier インストールガイド
Chapter 3 Balancing and Setup
44
Switch S1 Position Information for AGC Stations
Position 1
Thermal Setup Mode
Thermal Setup Mode
Position 2
Manual Setup Mode
Manual Setup Mode
Position 3
AGC Operational Mode
AGC Operational Mode
A thermistor (thermal) driven
circuit on the amplifier sets the
DC control voltage that drives
the Bode.
This circuit detects the
amplifier’s internal temperature
and generates the proper level
of DC control voltage, setting
the proper loss characteristics of
the Bode with respect to the
current outdoor temperature.
Note: This is the same as the
“Thermal” toggle switch setting
on most prior AGCs.
circuit on the amplifier sets the
DC control voltage that drives
the Bode.
This circuit detects the
amplifier’s internal temperature
and generates the proper level
of DC control voltage, setting
the proper loss characteristics of
the Bode with respect to the
current outdoor temperature.
Note: This is the same as the
“Thermal” toggle switch setting
on most prior AGCs.
The Manual Backoff
potentiometer sets the DC control
voltage that drives the Bode.
Manually adjusting the Manual
Backoff potentiometer sets the
proper loss characteristics of the
Bode with respect to the current
outdoor temperature.
Manual adjustment is done by
monitoring the amplifier RF
output level and adjusting the
potentiometer to reduce the gain
“x” dB from the full gain
(minimum loss) of the
potentiometer setting.
The value of “x” (gain reduction)
is dependant upon outside
temperature and is determined by
consulting the Manual Backoff
Chart (on page 49).
Note: This is the same as the
“Manual” toggle switch setting on
some prior AGCs.
potentiometer sets the DC control
voltage that drives the Bode.
Manually adjusting the Manual
Backoff potentiometer sets the
proper loss characteristics of the
Bode with respect to the current
outdoor temperature.
Manual adjustment is done by
monitoring the amplifier RF
output level and adjusting the
potentiometer to reduce the gain
“x” dB from the full gain
(minimum loss) of the
potentiometer setting.
The value of “x” (gain reduction)
is dependant upon outside
temperature and is determined by
consulting the Manual Backoff
Chart (on page 49).
Note: This is the same as the
“Manual” toggle switch setting on
some prior AGCs.
The AGC detector circuit monitors
the AGC pilot carrier level at the
input to the AGC module. The
detected AGC pilot carrier level
variations cause a proportional
variation of the DC control voltage
that drives the Bode.
Important: The switch must be left
in this position after initial
balancing in order for the AGC to
function with the Bode properly.
The AGC and Bode combination
thus cause offsetting gain and
slope variations to occur as
needed, holding the actual
amplifier output stable.
Note: This is the same as the
“Auto” toggle switch setting on all
prior AGCs.
the AGC pilot carrier level at the
input to the AGC module. The
detected AGC pilot carrier level
variations cause a proportional
variation of the DC control voltage
that drives the Bode.
Important: The switch must be left
in this position after initial
balancing in order for the AGC to
function with the Bode properly.
The AGC and Bode combination
thus cause offsetting gain and
slope variations to occur as
needed, holding the actual
amplifier output stable.
Note: This is the same as the
“Auto” toggle switch setting on all
prior AGCs.
Note: AGC operational mode is used only after the station has been initially balanced in either
thermal or manual setup mode.
thermal or manual setup mode.
Switch S1 Positions for Thermal Stations
The mode of thermal compensation you select for a thermal station determines the
position in which you place switch S1.
position in which you place switch S1.
Position 1 - Selects amplifier only compensation mode
Position 2 - Not used
Position 3 - Selects amplifier and coax compensation mode
Bode Network
The Bode Network, or Bode, is an interstage variable attenuation and slope network
whose loss characteristics are driven by DC control voltage.
whose loss characteristics are driven by DC control voltage.
The position of switch S1 sets the DC control voltage driving the Bode according to
the setup mode or operational mode required for the station.
the setup mode or operational mode required for the station.
Refer to the following table for more information on choosing the correct switch
position for your application.
position for your application.