
INSTALLATION AND SERVICE
MANUAL
CONTINUOUS DUTY
VHF POWER AMPLIFIER
August 10, 2007 Rev B
Crescend Technologies
920 E. State Parkway
Schaumburg, IL 60173
Copyright Crescend Technologies Rev B
Tel: 847 908 5400
Fax: 847 908 5408
Email: sales@CrescendTech.com
Web Site: www.CrescendTech.com

GENERAL DESCRIPTION
Warning! Changes or modifications not expressly approved by the party
responsible for compliance could void the users’ authority to operate the
equipment.
Compliance
subject to the following two conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received, including
interference that may cause undesired operation.
1.1. INTRODUCTION
This manual contains information and procedures for installation, operation, and general
maintenance of Crescend’s VHF Continuous Duty Power Amplifier.
1.2. PRODUCT DESCRIPTION
The Crescend Technologies VHF RF power amplifiers are designed for trunking and
conventional repeater applications. Rack mountable and designed to accept a range of
input powers for a given rated output power, the amplifier covers a broad range of
frequencies. Closed loop power control is used to maintain a constant output power under
varying voltage, signal input, frequency and output load conditions. Several design features
work to protect the amplifier under adverse conditions.
The amplifier front panel includes status LED indicators for DC and Alarm conditions. RF
Input, RF Output, DC, summary alarm and power cutback connections are found on the
back of the amplifier. A fan is used to cool the amplifier.
Table 1-1. Amplifier Functional Specifications
Frequency Range: See Table 1-2 (Range Set at Factory)
Operating Voltage: +13.8 ±0.7 Vdc
Current Consumption: See Table 1-2
Duty Cycle: 100%
Power Input: See Table 1-2 (Range Set at Factory)
Power Output (Single Carrier Operation): See Table 1-2 (Range Set at Factory)
Input Return Loss: -10 dB (Maximum)
Spurious & Harmonics: See Table 1-2
Input/Output Impedance: 50 Ohms (Nominal)
Load VSWR Tolerance: VSWR Protected above 2.5:1 (Nominal)
Input/Output Connector: Type N Female
Vertical Mounting: 7.0 in
Horizontal Mounting: 19.0 in
Weight: 10 lbs (4.6 kg) (Nominal)
Cooling Method: Fan Forced Air Over Heat Sink
Operating Temp. Range: -30°C to +60 °C
Storage & Transport: -40 °C to +70 °C
Humidity: 80% at +40 °C (Non-Condensing)
Altitude: 10,000 Feet (Maximum)
Front Panel Display:
This device complies with part 15 of the FCC rules. Operation is
INDICATORS
Copyright Crescend Technologies 2 Rev B

Alarm and Control Pins:
DC ON (Green), LOW OUTPUT (Red),
HIGH VSWR (Red), OVER TEMP (Red)
SUMMARY ALARM
Summary of Low Output, High VSWR, Over
Temp Alarms
CONTROLS
CTRL(Partial Power Cutback)
SH/D (External Power Control)
Copyright Crescend Technologies 3 Rev B

Table 1-2. Frequency Ranges, Input/Output Power, Current, Spurious and Harmonics
Typ
Frequency
Range (MHz)
136-144 (DA)
144-152 (DB)
152-162 (EA)
162-174 (EB)
NOTES:
All specifications above apply at +13.8 ± 0.1 VDC operating
Input Power
Range (W)
0.1-0.2
0.2-0.5
0.5-1
1-2
2-5
5-10
10-20
20-50
Manufacturer’s Rated Output Power of this Equipment is for
Single Carrier Operation.
voltage, ambient temperature of 25°C ± 5°C.
Rated Output
Power (W)
80 (P8)
100 (P10)
110 (P11)
150 (P15)
Current
(A)
16
18
22
26
Max
Current
(A)
19
23
25
28
Spurious
and
Harmonic
s (dBc)
<
-65
<-65
<
-65
<-67
Copyright Crescend Technologies 4 Rev B