Installation and Operating Manual VHF, Bi‐Directional Amplifier BDA‐VHF‐33/33‐80‐20RU18
TABLE OF CONTENTS PARAGRAPH PAGE NO BDA OVERVIEW and PART NUMBER DESCRIPTION (Table 1) 3 BDA BLOCK DIAGRAM DESCRIPTION 3 OPTIONAL EQUIPMENT OVERVIEW 3 BDA BLOCK DIAGRAM DRAWING (Figure 1) 4 ELECTRICAL SPECIFICATIONS 5 MECHANICAL SPECIFICATIONS 6 ENVIRONMENTAL CONDITIONS 6 BDA CONNECTIONS 7 RF EXPOSURE WARNING 7 MECHANICAL OUTLINE DRAWING (Figure 2 & 2a) 8 OPTIONAL BATTERY BACK-UP CONFIGUATION (Figure 3) 9 BDA INSTALLATION 10 BDA OPERATION 11 GAIN ADJUSTMENT/ LED DESCRIPTION (Fig
BDA OVERVIEW: The BDA assembly extends the coverage area of radio communications in buildings and RF shielded environments. The unit features low noise figure and wide dynamic range. It is based on a duplexed path configuration with sharp out of band attenuation allowing improved isolation between the receiving and transmitting paths.
Block Diagram Drawing: Figure 1 1. First stage Internal Filter Downlink -This highly selective filter provides additional rejection for increased isolation. 2. Downlink LNA- Is a low noise amplifier which offers 26 db Gain and establishes the Noise Figure of the downlink path. 3. Internal Filter Downlink - This highly selective filter gives additional rejection for increased isolation. 4. Downlink Pre-amp - Is a low noise amplifier that drives the downlink MPA and offers 16dB Gain. 5.
Electrical Specifications: BDA-VHF-33/33-80-20RU18 Specifications Typical Frequency Range : 138-174 MHz Bandwidth : 1-5 MHz Minimum passband separation : 2 MHz Pass band Gain @ min attenuation : 80 dB (Max.) Variable Step Attenuator Range (1-dB steps) : 0-31 dB Gain Flatness : ±1.5 dB (Typ.) Noise Figure @ +25⁰C at Max. gain : 5.5 dB (Max.) 5.0 dB (Typ.) 3rd Order Intercept point @ 2 tones +30dbm each : +54 dbm Composite Output Power : +33 dBm (Typ.) Output Power ALC Set : +33 dBm (Typ.
Mechanical Specifications: Size : 40.0 x 21.0 x 22 inch RF Connectors : N-Type Female Weight : < 212 lb / (84 kg) approx. (Additional Filter Rack not included) Environmental Conditions: The unit is designed for indoor applications: Operating temperature: - 20°C to +50°C Storage temperature: - 40°C to +85°C FCC NOTE: The product has been tested and found to comply with the Booster requirements per FCC Part 90 This is a Class B device.
BDA CONNECTIONS: The BDA AC power is accepted through a standard 3-wire male plug (IEC-320) with phase, neutral and ground leads. The AC power is wired to a high efficiency DC switching power supply which is CE and UL approved. The power supply runs the amplifiers and the Power On lamp. The metal enclosure of the BDA is connected to ground. An optional 9-pin D-Sub connector provides failure alarm output contacts (see diagram next page) as well as an optional 12 VDC (250 mA) auxiliary output.
Mechanical Outline Drawings: Optional DC Power Input (S1) Figure 2 Conditions for Optional Alarm The alarm monitors current of both uplink and downlink amplifiers. An alarm condition will occur if either uplink or downlink amplifiers are over or under its current tolerance or if there is no DC power present.
Optional Battery BackUp Configuration: 15 Amp Fuse + + - - 12 Volt 12 Volt Lead-Acid Lead-Acid Battery Battery 15 Amp - + Battery of - BDA Figure 3: Optional Battery Back-Up Configuration Battery Back-Up Time Recommend Battery Rated Capacity (20 Hour Rate) Typical DC Current Rating for BDA-XXX-33/33-80 1.5 Hour 2.5 Hours 3 Hours 5 Hours 4.3 Amp Hours 7.2 Amp Hours 8.6 Amp Hours 14.4 Amp Hours 2.3 Amps 2.3 Amps 2.3 Amps 2.
BDA Installation: DO NOT APPLY A.C. POWER TO THE BDA UNTIL CABLES ARE CONNECTED TO BOTH PORTS OF THE BDA AND THE ANTENNAS. 1. Set the BDA Rack on the floor or mount on a wall (where applicable). Using appropriate screws and anchors, attach the BDA to the wall at the four mounting holes on the side flanges. (Special version not shown in this manual). 2. Ensure that the isolation between the donor antenna and the service antenna is at least 12 dB greater than the BDA gain.
BDA Operation: Refer to figure 4 for adjustment access location and label. Variable Step Attenuator BDA gain can be attenuated, for Uplink and Downlink separately, up to 31 dB in 1 dB steps using the variable step attenuator (Figure 4). To adjust the attenuation up to 11 dB, use the dialer on the front panel. To adjust the attenuation up to 31 dB, set the thumbnail switch to +10 dB, and then dial in the remaining attenuation via the dialer.
Operation of the BDA at minimum attenuation with greater than -45 dBm average power incident on either BASE or MOBILE port can cause damage to the BDA.
Diagnostic Guide: The BDA provides long term, care-free operation and requires no periodic maintenance. There are no user-serviceable components inside the BDA. This section covers possible problems that may be related to the installation or operating environment. a. Gain Reduction Possible causes: Defective RF cables and RF connections to antennas, damaged antennas. b. Excessive Intermodulation or Spurious Possible causes: Amplifier oscillation caused by insufficient isolation.
