INSTALLATION AND SERVICE MANUAL CONTINUOUS DUTY UHF POWER AMPLIFIER July 3, 2008 Crescend Technologies 920 E. State Parkway Schaumburg, IL 60173 Copyright Crescend Technologies Tel: Fax: Email: Web Site: 847 908 5400 847 908 5408 sales@CrescendTech.com www.CrescendTech.
GENERAL DESCRIPTION 1.1. INTRODUCTION This manual contains information and procedures for installation, operation, and general maintenance of Crescend’s UHF Continuous Duty Power Amplifier. 1.2. PRODUCT DESCRIPTION The Crescend Technologies UHF 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.
Table 1-2. Input/Output Power, Current, Spurious and Harmonics Input Power Range (W) Rated Output Power (W) Typ Current (A) Max Current (A) 0.1-0.2 0.2-0.5 0.5-1 1-2 2-5 5-10 10-20 20-50 80 (P8) 100 (P10) 18 21 23 26 NOTES: Manufacturer’s Rated Output Power of this Equipment is for Single Carrier Operation. All specifications above apply at +13.8 ± 0.1 VDC operating voltage, ambient temperature of 25°C ± 5°C.
2. INSTALLATION 2.1. INTRODUCTION This section contains installation recommendations, unpacking, inspection, and installation instructions for the amplifier. Carefully read all the material in this section prior to equipment unpacking or installation. Also read and review the operating procedures in Section 3 prior to installing the equipment. It is important that the licensee perform these tasks correctly and in good faith.
6. If remote output power cutback of PA is desired, connect control cable to “CTRL” pin on rear of amplifier module. See section 2.5 for more details. 7. Measure primary DC input voltage. DC input voltage should be +13.8 +/- 0.1VDC. Turn off DC voltage. WARNING: Turn off external primary DC power before connecting DC power cables. 8. Connect positive primary power wire (+13.8VDC) to terminal marked +13.8VDC and negative primary power wire to GND terminal on rear of amplifier. 9.
3. GENERAL OPERATING INFORMATION 3.1. INTRODUCTION This section contains operating instructions for the amplifier. 3.2. STATUS INDICATORS The function of the amplifier status indicators and is described in Table 3-1. Table 3-1. Amplifier Status Indicators STATUS LED FUNCTION DC ON Green LED. Illumination indicates DC Power has been applied. LOW OUTPUT Red LED. Activates when the output power drops to approximately 70-80% of set output power. HIGH VSWR Red LED.
Warning: Be sure that the signal frequency is in the range 403 – 470 MHz! 5. Turn off RF input signal. The fan should continue running, but turn off after approximately 6-12 seconds. 4. PRINCIPLES OF OPERATION 4.1. INTRODUCTION This section contains principles of operation of the RF Power Amplifier. 4.2. RF INPUT SIGNAL The amplifiers are set at the factory to work over different input power ranges. The available range of inputs ranges may be found in Table 1-2. 4.3.
5. MAINTENANCE 5.1. INTRODUCTION This section contains periodic maintenance and performance test information for the amplifier. NOTE: 5.2. Check your sales order and equipment warranty before attempting to service or repair the unit. Do not break the seals on equipment under warranty or the warranty will be null and void. Do not return equipment for warranty or repair service until proper shipping instructions are received from the factory.
5.4. TEST EQUIPMENT REQUIRED FOR TEST Test equipment required to test the amplifier performance is listed in Table 5-2. Equivalent test equipment may be substituted for any item. NOTE: All RF test equipment must be calibrated to 0.05 dB resolution. Any deviation from the nominal attenuation must be accounted for and factored into all output readings. Table 5-2. Test Equipment Required (or equivalent) EQUIPMENT MANUFACTURER MODEL Signal Generator (1) H.P.
6. TROUBLESHOOTING 6.1. INTRODUCTION This section contains a list of potential problems and suggested actions to be taken. If the suggested corrective action does not eliminate the problem, please contact your Crescend factory for further instructions. NOTE: Check your sales order and equipment warranty before attempting to service or repair the unit. Do not break the seals on equipment under warranty or the warranty will be null and void.
Operating temperature of amplifier is exceeding safe level. Note: When unit cools, LED turns off and output returns to rated power 2. 3. 4. Copyright Crescend Technologies 11 Make sure that air access to front and rear of unit is unimpeded Verify that air vents are clear of dust and dirt and that fan(s) are operating properly.
6.3. RETURN FOR SERVICE PROCEDURES When returning products to Crescend, the following procedures will ensure optimum response. 6.3.1. OBTAINING AN RMA A Return Material Authorization (RMA) number must be obtained prior to returning equipment to the factory for service. Please contact our Customer Service Department at 800-872-6233 to obtain this number. Failure to obtain this RMA number may result in considerable delays in receiving repair service. 6.3.2.
