Telephone User Manual

Station Apparatus
2000-series Telephones
Strata CTX I&M 06/04 11-53
Station Apparatus
DKT2020-FDSP Full-Duplex Speakerphone with External
Microphone
The DKT2020-FDSP is designed to allow both parties of a speakerphone call to speak
simultaneously. This eliminates “clipping” and enables true two-way conversation. However,
when two parties are talking simultaneously, the performance is not as good as on a handset. The
technology necessitates some volume loss in this situation.
An optional External Microphone can be connected for improved performance. However, the
External Microphone is extremely directional and should only be used in certain applications. The
telephone also provides half-duplex/full-duplex manual selection.
The DKT2020-FDSP has three operational modes for enhanced microphone use (Best, Good and
Normal). These modes allow adjustments for different room acoustical characteristics. Choosing
either the Internal or External Microphone (RFDM) and proper operational mode should be pre-
selected by the system installer.
When the External Microphone option is installed, the telephone’s Internal Microphone is disabled
on all but Voice First Handsfree Answerback calls and OCA calls. The External Microphone is
powered by the phone (no batteries are required) and does not need to be turned off when not in
use.
Choosing either the Internal or External Microphone is performed on the DIP switch 5, located
under the keystrip (see Figure 11-35).
Important!
The DKT2020-FDSP’s full-duplex operation depends on the speaker volume setting. Raising or
lowering speaker volume directly affects the performance of the full-duplex operation.
• Depending on the room’s echo characteristics, raising the volume of the speakerphone can
cause the full-duplex operation to deteriorate. When set to maximum volume, it may be
necessary to switch to half-duplex operation.
• The speakerphone will automatically reduce volume in each direction when both the FDSP
user and the distant party are talking at the same time. The volume reduction is required to
control the echoes at high volume levels. It is possible for surrounding conversations and other
sounds to trigger this effect even when you are not speaking.
• The performance of the DKT2020-FDSP can vary on calls that involve a delay, such as
wireless calls, Voice Over Internet Protocol calls, etc. With these types of calls, the quality can
diminish.
• When using the [PDN] or Intercom button, the performance for internal calls is not as good as
for external calls.
DIP Switches
The DKT2020-FDSP has DIP switches that enable the External Microphone and use telephone use
in other countries. The DIP switches are under the flexible button key strip (see Figure 11-35).
There are three different DIP switch settings for optimum operation in various types of
environments:
• Best – provides full-duplex operation with the Internal or External Microphone. This is ideal
for a large enclosed area, such as an office with little echo. Echo varies according to the
environment. For instance, a room that is relatively empty has more echo than a room with
furniture or items that can absorb sound waves.