G Way Solutions VHF2W80 Users Manual
Installationand
OperatingManual
VHF,Bi‐DirectionalAmplifier
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 (Figure 4) 12
DIAGNOSTICS GUIDE 13
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BDAOVERVIEW:
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. Due to significant size of the diplexers and/or High “Q” filters
needed to achieve specified gain, the system is built as Amplifier 19” Drawer and external filters,
assembled into a 19”, 20U cabinet.
VHFPartNumberDescription:
BDA-V(XXX)/(YYY) – 33/ 33-80-(ZZZ)
V(XXX) (YYY) 33 33 80 (ZZZ)
BDA
High Band
Center
Frequency
[MHZ]
Low Band
Center
Frequency
[MHZ]
UL
Composite
Power
[dbm]
DL
Composite
Power
[dbm]
Table 1
Gain Enclosure
BDABlockDiagramDescription:
Refer to Figure 1, on page 4 for the following discussion.
The BDA Downlink path receives RF signals from the base station and amplifies and transmits
them to the subscriber. The BDA Uplink path receives RF signals from the subscriber and
amplifies and transmits them to the base station. The Uplink and Downlink occupy two distinct
frequency bands. For example, a sample frequency band in VHF is as follows: 158-159 MHz for
the Uplink and 154-156 MHz for the Downlink. Two diplexers isolate the paths and route each
signal to the proper amplifying channel.
An Automatic Level Control (ALC) allows for output power limiting. A variable step attenuator
gives 0 – 31 dB of attenuation in 1 dB steps. The use of these controls is covered in the
“OPERATION” section, page 10.
OptionalEquipmentOverview:
a) Visual Alarms
All G-Wave BDAs feature visual alarms as a standard. LEDs are provided for UL and DL alarms,
ALC UL and DL alarms as well as Power indicator.
b) DC Input Power Option (S1)
The BDA is equipped with both AC and DC voltage inputs for power operation. This gives the
flexibility of powering the BDA with either an AC or DC source. If both sources are connected,
the BDA will automatically select the stronger source for power.
c) Remote Monitoring via 9-Pin Dry Contact Connector (RM9)
A 9-Pin dry contact will be provided to hard wire into a building’s alarm system. Dry contact will
provide alarms for ALC and amplifier failure.
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BlockDiagramDrawing:
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. Downlink MPA - Is a medium power amplifier with an ALC circuit which offers 42dB
Gain.
6. Low Pass Filter Downlink- This low pass filter provide a rejection of harmonics.
7. Output Diplexer – Has a low bandpass insertion loss and high selectivity for one distinct
downlink/uplink frequency band.
8. First stage Internal Filter Uplink - This highly selective filter gives additional rejection
for increased isolation.
9. Uplink LNA- Is a low noise amplifier which offers 26 db Gain and establishes the
Noise Figure of the Uplink path.
10. Internal Filter Uplink - This highly selective filter gives additional rejection for
increased isolation.
11. Uplink Pre-amp - Is a low noise amplifier that drives the Uplink MPA and offers 16dB
Gain.
12. Uplink MPA - Is a medium power amplifier with an ALC circuit which offers 42dB
Gain.
13. Low Pass Filter Downlink- This low pass filter provide a rejection of harmonics.
14. Input Diplexer – Has a low bandpass insertion loss and high selectivity for one distinct
downlink/uplink frequency band.
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