48910, 920, 930 User's Manual 200 Pondview Drive, Meriden, CT 06450 • (877) 737-9675 • Fax (203) 821-3852 www.rfsworld.
Disclaimer All information and statements contained herein are accurate to the best of the knowledge of Radio Frequency Systems, but Radio Frequency Systems does not make any warranty with respect thereto, including without limitation any results, which may be obtained from the products described herein or the infringement by such products of any proprietary rights of any persons.
TABLE OF CONTENTS GENERAL STATEMENTS .................................................................................................................................. 4 MAXIMUM PERMISSIBLE EXPOSURE LIMITS........................................................................ 5 PRODUCT OVERVIEW........................................................................................................................................... 6 FIELD TUNE-UP, ALIGNMENT OR CALIBRATION .................................
General Statements Thank you for selecting this RFS product. We are confident that you will find this product in proper working order, meeting all stated specifications. If not, please contact customer service immediately at 1-800-321-4700 and we will resolve the issue without hesitation. Please read this manual. A full understanding of product operation will support optimal performance and prevent accidental damage not covered by the stated warranty.
Maximum Permissible Exposure Limits THIS PRODUCT IS CATEGORICALLY EXCLUDED FROM ROUTINE ENVIRONMENTAL EVALUATION ACCORDING TO CFR 47, SECTION 1.1037. Repeaters like the 48900 series generate radio signals and thereby give rise to electromagnetic fields. The installer is expected to have a complete understanding of CFR Title 47, Sections 1.1307 and 1.1310. A brief discussion follows but is not intended to be a substitute. Additional information can also be obtained from OET Bulletin 65.
maximum output power (+22 dBm); the resultant ERP is +40 dBm or 10,000 mW. OET Bulletin 65 provides the following formula for calculating the pow er density with the EPA recommended factor for ground reflection: 1.05 ERP/ π R2 Where R is the distance to center (of any body part of person). Solving for 10,000 mW @ 3ft. (91.44 cm) we get a power density of 0.4 mW per cm 2.
Theory of Operation The 48900 signal boosters are designed to enhance radio communication in buildings, basements, tunnels and other RF shielded environments. The 48910 is tuned for the 800 MHz Cellular band, the 48920 for the 800 SMR band and the 48930 for the 900 MHz SMR band. These units work by receiving and amplifying the base TX signals via a donor antenna directed at the desired base site. This RF path is called the downlink.
Electrical Specifications Downlink 869-894 851-869 935-941 65 dB ±2.0 dB 20 dB 20 dB 4.0 dB +22 dBm +19 dBm 50 Ohms 1.5 <0.5 microsecond 110 VAC@ .
Intermodulation, Power, and AGC Per CFR Title 47, Part 90, there shall be no spurious emissions greater than {43+ 10 Log 10 (Power Out Watts)} dB below the carrier Power Out (dB) level. This is always equivalent to -13 dBm. The primary contributor to spurious emissions is multiple signal intermodulation. As multiple signals are amplified, they generate intermodulation products (IM).
In all cases, the actual signal output power is equal to the input signal power plus the gain of the repeater. If a signal level of -80 dBm exists at the input to the repeater and the gain is 65 dB, the resulting output will be –15 dBm dBm, not +9 as noted in the previous paragraph. +9 dBm in this case is the maximum output for 16 channels.
External Filter Ports SMA female connectors on the faceplate of the 48900 allow for connection of externally mounted passive 50 Ohm filtering. The external filter then modifies the related passband. Should the conditions change in the field, the external filter can be removed or replaced with minimal interruption in service. RFS has a variety of filter options, see the application notes on our website of contact RFS Applications Engineering for assistance.
§ Install service area antenna(s). Determining the location and type of service area antennas is part of the distribution system design. Generally, it is desired to minimize the amount of coax that has to be installed. However, in buildings with extensive obstructions, it may be necessary to install several service area antennas. For assistance with antenna placement, contact RFS Applications Engineering.
Antenna Isolation Isolation between the donor (base) antenna and service area antenna should be 20 dB greater than the gain of the repeater amplifier. If the isolation is less than the amplifier gain, then positive feedback sufficient for oscillation is present in the system. Such oscillations will overdrive one or both amplifier chains and continuously activate the AGC auto-shutdown circuitry. This situation will be apparent by the red fault LED being lit.
Problem: Green power LEDs on faceplate not lit. Red LED on faceplate is lit. Green power LED lit and no red Fault LED on faceplate; unit does not appear to be working. Yellow AGC LED is lit. Solution: Check power source and the AC fuse located in the EIC plug. Check the DC fuse located inside the 48900 on the side of the individual amplifier modules. Check connections to the internal power supply. First try to cycle the power then watch the AGC LEDS to make sure the unit is not in AGC shut down.
Maintenance, Repair and Warranty Periodic Maintenance There is no periodic maintenance required for the 48900. As long as the units are kept away from extreme temperatures and moisture, they should provide long-term, carefree operation. However, periodically check all RF connections for corrosion, strain damage, and proper tightness. Also, periodically check the AC power connections for integrity.
