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Page 8 of 10

TN-1114-AN

© Tait Electronics Limited 21 December 2005

4.

Select one of the 

Extended bypass

 check boxes. This selects the 

other 

Extended bypass

 check box as well. (You cannot configure 

extended bypass separately for the transmit and receive paths.) 

7

Performance Specifications

Extended bypass has been tested with external modems as follows:

The performance figures given in these specifications are typical, and are 
supplied only as a guide to the expected performance.  The actual 
performance achieved by your system will depend on the specific external 
modem used, and the interface levels into the TB8100.

narrow bandwidth C4FM

9600bps
external modem based on a CML FX919 chipset

narrow bandwidth GMSK

BT=0.5, 4800bps
external modem based on a CML FX489 chipset

wide bandwidth GMSK

BT=0.5, 9600bps
external modem based on a CML FX489 chipset

NB C4FM

NB GMSK

WB GMSK

Minimum Receiver RF Level for a Robust Link

––

a

–109dBm
(0.79

µ

V)

–109dBm
(0.79

µ

V)

Strong Signal Packet Error Rate (PER)*

*for RF levels of 0dBm

<10

-4

<10

-4

<10

-4

Signal Displacement Bandwidth

>1kHz

>1kHz

>2kHz

Selectivity

––

a

71dB

79dB

Modulation Fidelity*

*measured as Error Vector Magnitude, through combined 
receive and transmit paths

3.5%

6%

6%

a. Unavailable at time of publication.

Summary of Contents for TB8100

Page 1: ...TB8100 base station Using a TB8100 with an External Modem Application Note TN 1114 AN 21 December 2005...

Page 2: ...5 Connecting the TB8100 to an External Modem 5 6 Configuring the Base Station 7 7 Performance Specifications 8 8 Frequency Response Graphs 9 Associated Documentation TB8100 Installation and Operation...

Page 3: ...performance has been tested using only the unbalanced line interface on an isolated system interface board TBA10B0 Note The TB8100 does not check the extended bypass functionality against the hardware...

Page 4: ...ve audio bypass path received audio from the FM demodulator is decimated from 50kHz to 25kHz It is then directly converted to the analogue unbalanced line output with no further filtering Extended Byp...

Page 5: ...system interface board the transmit path is DC coupled with a bias of 2 5V and the receive path is AC coupled We recommend that you enable the high pass filter in the Signal Path tab of the channel pr...

Page 6: ...em to cope with the timing sequence of audio presented from the unbalanced line Refer to the TB8100 Specifications Manual for gating response times Tx Key If you do not require continuous transmission...

Page 7: ...come non compliant It should be selected only when the TB8100 is connected to approved level controlled devices modems trunking controllers etc Important With extended bypass you cannot use the balanc...

Page 8: ...system will depend on the specific external modem used and the interface levels into the TB8100 narrow bandwidth C4FM 9600bps external modem based on a CML FX919 chipset narrow bandwidth GMSK BT 0 5 4...

Page 9: ...y Publication History Amendment Record Tait Contact Information Corporate Head Office New Zealand Tait Electronics Limited P O Box 1645 Christchurch New Zealand E mail Marketing taitnet taitworld com...

Page 10: ...Page 10 of 10 TN 1114 AN Tait Electronics Limited 21 December 2005...

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