Design Guide for the Model 428D-83I-01-M/C-110/48 TTA System

Transcription

1 Design Guide for the Model 428D-83I-0-M/C-0/48 TTA System 8625 Industrial Parkway, Angola, NY 4006 Tel: Fax:

2 Table Of Contents Tower Top Amplifier... 3 Multicoupler Control Unit (MCU)... (4-6) Control Management Unit (CMU)... (7-9) Optional Narrowband Filter... 0 MCU Expansion Deck... 0 Design Considerations... Pa g e 2 08/4/204

3 Design Components Tower Top Amplifier (428D-83I-0-T) - The Tower Top Amplifier (TTA) uses a quadamplifier design to overcome the losses of a long transmission line. A preselector is included in the tower top box with a 28 MHz bandwidth (796 to 824 MHz). Figure : Picture and block diagram of the tower top box. 08/4/204 Page 3

4 Multicoupler Control Unit (428D-83I-0-M-0/48) - The Multicoupler Control Unit (MCU) provides additional amplification to overcome the distribution loss of the microcoupler (see Figures 2, 3, 4, and 5). The multicoupler has the ability to distribute to 6 receivers and can be expanded to 32 with an additional shelf. The unit has adjustable attenuators for setting Reserve Gain of the system. Each amplifier assembly within the system is monitored to provide alarm indications. Form-C relay outputs are provided to interface to supervisory alarms systems. The standard unit is designed for 20 VAC operation but by adding 48 to the end of the part number instead of 0, the unit will be designed for -48 VDC operation. Figure 2: MCU Picture. Front, rear, and overhead views. Page 4 08/4/204

5 Figure 3: Block diagram of the MCU. Tower Top Box Antenna Main Trans MCU Station Receivers Figure 4: Physical installation of MCU. 08/4/204 Page 5

6 RX TX WARNING Failure to ground the TTA System properly can result in equipment failure caused by electrical surges. Tower Top Amplifier 2 * ** GROUNDING REQUIREMENTS Surge protectors 6, 7, and must be grounded to the Master Ground Buss. MCU ground stud must be connected to the Equipment Rack Master Ground Bar. NOTE Building entry-point ground plate and Equipment Rack Master Ground Bar must be grounded to Master Ground Buss. Internal Perimeter Ground (Halo) Master Ground Buss Ant Main Transmit Combiner To Electrical Service Ground From Repeaters 8 7 * 0 Main (RF In) ** Equipment Rack Master Ground Ba BNC Port * 5 Entry-Point Ground Buss MCU Copper Ground Strap Building Entry-Point Ground Plate Figure 5: Electrical installation of MCU. Pa g e 6 08/4/204

7 Control Management Unit (428D-83I-0-C-0/48) - The Control Management Unit (CMU) interfaces the TTA to the ESS GTR8000 radio system (see Figures 6, 7, 8, and 9). The CMU provides a single RF output for interface to the ESS. There are no receive ports or expansion ports provided since receive distribution is included in the ESS. The unit has an adjustable attenuator for setting Reserve Gain of the system. Each amplifier assembly within the system is monitored to provide alarm indications. Form-C relay outputs are provided to interface to supervisory alarm systems. The standard unit is designed for 20 VAC operation but by adding 48 to the end of the part number instead of 0, the unit will be designed for -48 VDC operation. Figure 6: CMU Picture. Front, rear, and overhead views. 08/4/204 Pa g e 7

8 Figure 7: Block diagram of the CMU. Figure 8: Physical installation of CMU. Pa g e 8 08/4/204

9 Tower Top Amplifier 2 4 WARNING Failure to ground the TTA System properly can result in equipment failure caused by electrical surges. * ** GROUNDING REQUIREMENTS Surge protectors 6, 7, and must be grounded to the Master Ground Buss. CMU ground stud must be connected to the Equipment Rack Master Ground Bar. Building entry-point ground plate and Equipment Rack Master Ground Bar must be grounded to Master Ground Buss. Internal Perimeter Ground (Halo) Master Ground Buss Main Transmit Combiner 2 6 To Electrical Service Ground From Repeaters 8 7 * 0 ** Equipment Rack Master Ground Ba BNC Port * 5 Main (RF In) Entry-Point Ground Buss Copper Ground Strap Building Entry-Point Ground Plate CMU Figure 9: Electrical installation of CMU. 08/4/204 Page 9

10 Optional Narrowband Filter - The narrowband filter is designed to help limit the bandwidth of the system. The option is shipped from the factory as shown in Figure 0 ready to be interconnected to the deck. It is recommended that the optional filter be mounted in the same rack just above the deck. There are a total of 9 different narrowband filters available as shown in the table below. Figure 0: Optional Narrowband Filter. Figure : Optional Expansion Deck. MCU Expansion Deck (75-83K-0) - The multicoupler expansion deck will increase the total multicoupler outputs of the system to 32. The expansion deck is not used with the CMU style system. The optional deck is shipped with the required interconnect cable (as shown in Figure ) and is designed to be installed in the same rack but below the MCU deck. Page 0 08/4/204

11 Design Considerations Surge Protectors - The TTA system utilizes standard receive DC Pass surge protectors. These surge protectors must be provided by the engineer. The recommended surge arrestors (see Figure 2) from PolyPhaser are shown in Figure 5 and Figure 9 and are designated as item 6, 7, and. Torquing specification obtained with proper Torque Wrenches is required to properly tighten all connectors. See Torquing Initiative document for more information. The 09 is an optimized arrestor with improved performance. The TSX protector is not only an optimized protector but also complies with our 50 dbc PIM and 25kW PIP requirements. All transmit protectors will utilize 7-6 DIN connectors. DS09050WA (N male to antenna) (N female to equipment) DS09050WD (N female to antenna) (N female to equipment) DSTSXDFMBF (DIN female / male) DSTSXDFFBF (DIN female / female) Transmit Protector Receive Cable and Port Protector Figure 2: PolyPhaser Surge Arrestor Part Number and Picture. Cable - The test cable connects the Control Unit with the TTA. This allows the TTA to be tested from the bottom of the tower but emulates a signal at the input to the TTA. The test cable should be constructed with LDF4 or equivilent /2 Heliax. Superflex cable is never recommended for outside use. A surge protector must be installed at the exit to the building. ing and Alignment - ing the TTA system involves following the 5-step procedure. The Reserve Gain is adjusted according to the procedure. In the case of the MCU style system, the distribution gain is also adjusted. Standalone or interface to other radios - The MCU was designed to allow individual radios to be connected to the TTA system. The ESS can also be utilized to interface external receivers and allow radio expansion outside the ESS. 08/4/204 Page

12 8625 Industrial Parkway, Angola, NY 4006 Tel: Fax: