User's Manual

Weehawken Tunnel VHF Repeater System
User/Maintenance Handbook
Handbook N.-Weehawken_VHF Issue No:-A Date:-05/08/05
Page:-
50 of 75
7. SUB-UNIT MODULES
Note that the sub unit modules are tabled in part number order – the modules pertinent to any
particular shelf will be found in the parts list under the heading of that shelf.
7.1
VHF High Band Bandpass + Notch Filter (01-003105)
7.1.1 Description
The bandpass filters are multi-section designs with a bandwidth dependent upon the passband
frequencies, (both tuned to customer requirements). The response shape is basically Chebyshev
with a passband design ripple of 0.1dB. The filters are of helical design, and are carefully
aligned during manufacture in order to optimise the insertion loss, VSWR and intermodulation
characteristics of the unit. The tuned elements are silver-plated to reduce surface ohmic losses
and maintain a good VSWR figure and 50 load at the input and output ports. The bandpass
filters fitted here have a notch filter as the final tuned element in their construction to
completely eliminate unwanted frequencies close to the band edge.
The notch reject filters should require no routine maintenance, being totally passive devices. If
a filter is suspected of failure, no invasive measures are recommended as even opening the case
of the device could render it unusable.
7.1.2 Technical Specification
PARAMETER SPECIFICATION
Passband: 155 - 160 MHz
Insertion Loss: 1.6 dB (typical)
RF Connectors: SMA
Power Rating: 100 Watt
Impedance: 50Ω
VSWR: Better than 1.2:1
operation: -10%C to +60%C Temperature
range
storage: -20%C to +70%C
Size: 348x102x55mm (case only)