Tait TB8100 User Manual page 129

Bypass
High pass filter
TB8100 Service Kit User's Manual
Option Description
Flat full band Passes audio evenly across the audio spectrum.
Flat speech Passes only speech frequencies.
band
Pre-emph Passes speech, amplifying higher frequencies. This option can be
speech band used for transmitting to systems with de-emphasis.
Pre-emph full Passes all audio, amplifying higher frequencies. This option can
band be used for transmitting to systems with de-emphasis.
Subaudible Passes only the subaudible band, containing any CTCSS tones or
band DCS codes. This option can be used to separate out the signalling
and put it on the line output that is connected to a tone panel.
Note: The Path B filter does not appear if the Bypass check box is
selected.
Bypasses the transmitter filters. This check box is generally cleared, but must be
selected for TaitNet MPT1327 trunked networks. Bypassing the filter
minimises the time delay through the base station. This is important when the
base station is handling FFSK data. See TN-745-AN for details.
Important: Bypassing the transmitter filters also bypasses the
limiters.This can cause over-deviation and void the equipment
compliance. The Bypass check box should only be selected when
approved level-control devices (for example, modems or trunking controllers)
are connected and appropriate action is taken to ensure that compliance
regulations are met.
The Bypass check box should be selected on the transmit path if that path will
carry externally generated subaudible signalling (for example, in QuasiSync
systems). If the transmitter filters are not bypassed, subaudible signalling will not
be transmitted when audio on the other transmit path causes limiting.
The High pass filter check box appears when the Bypass check box is selected.
The setting of the High pass filter check box is important for modems and other
wide band interface signals. For trunking and for quasi-synchronous
applications it should be selected, for paging and for complex modulation
modems it should be cleared.
Selecting the High pass filter check box inserts a high pass filter with a very low
3 dB cut frequency into the appropriate signal path; this effectively AC couples
the signal path.
Working with Channel Profiles 119