291
Chapter 8, Signaling Decoder Screen
Dual-Tone Multi-Frequency (DTMF) Decoder
Input Level
This field specifies the signal level that you input (after de-emphasis if used). The
higher the level of signal expected by the analyzer, the higher the trigger level is
set.
Operating Considerations
The unit-of-measure is determined by the
AF Anl In
setting.
The input level should be set high enough to prevent false triggering, but low
enough to allow triggering for fluctuating signal levels.
De-emphasis Effects
De-emphasis is a single-pole, low-pass filter with a 212.2 Hz corner frequency. It
is enabled/disabled using the
De-Emphasis
field on the AF ANALYZER screen.
(Refer to
Figure 15, "AF ANALYZER Functional Block Diagram," on page 100
.)
The Input Level is the expected level at the output of the de-emphasis network.
Assuming a mean DTMF frequency of approximately 1 kHz, decoding with de-
emphasis on (set to
750 µ
s) requires the input level to be set to 212/1000 = 0.212
times the peak deviation, or about 1/5 the incoming level of the tone.
Examples of Input Level Settings
Example 1
Peak deviation 3 kHz, De-emphasis off. Set the input level to 3 kHz.
Example 2
Peak deviation 3 kHz, De-emphasis 750 ms. Set the input level to 3
×
0.212 =
636 Hz
Содержание 8920A
Страница 14: ...Contents 14 2 Configuring Your Test Set General Operating Information 50 ...
Страница 17: ...Contents 17 5 AF Analyzer Screen Block Diagram 100 ...
Страница 19: ...Contents 19 7 Configure Screen Field Descriptions 254 ...
Страница 21: ...Contents 21 9 Duplex Test Screen Block Diagram 340 Field Descriptions 341 ...
Страница 23: ...Contents 23 11 Help Screen Field Descriptions 436 ...
Страница 24: ...Contents 24 12 I O Configure Screen Field Descriptions 438 ...
Страница 25: ...Contents 25 13 Message Screen Field Descriptions 444 ...
Страница 26: ...Contents 26 14 Oscilloscope Screen Field Descriptions 446 Using the Oscilloscope 452 ...
Страница 27: ...Contents 27 15 Print Configure Screen Field Descriptions 454 ...
Страница 29: ...Contents 29 17 RF Analyzer Screen Block Diagram 472 Field Descriptions 473 ...
Страница 30: ...Contents 30 18 RF Generator Screen Block Diagram 484 Field Descriptions 485 ...
Страница 31: ...Contents 31 19 RX Test Screen Block Diagram 494 Field Descriptions 495 ...
Страница 32: ...Contents 32 20 Service Screen Field Descriptions 502 ...
Страница 33: ...Contents 33 21 Spectrum Analyzer Screen Field Descriptions 506 Using the Spectrum Analyzer 518 ...
Страница 35: ...Contents 35 23 TX Test Screen Block Diagram 550 Field Descriptions 551 ...
Страница 38: ...Contents 38 Index 619 ...
Страница 39: ...39 1 Get Started ...
Страница 52: ...52 S HP892XX USRGUIDE manual configts fb Chapter 2 Configuring Your Test Set General Operating Information ...
Страница 98: ...98 S HP892XX USRGUIDE manual acpscrn fb Chapter 4 Adjacent Channel Power Screen Field Descriptions ...
Страница 99: ...99 5 AF Analyzer Screen ...
Страница 113: ...113 6 Call Processing Subsystem ...
Страница 129: ...129 Chapter 6 Call Processing Subsystem The CALL CONTROL Screen Figure 20 AMPS CALL CONTROL Screen with Meas Selected ...
Страница 252: ...252 S HP892XX USRGUIDE manual callscrn fb Chapter 6 Call Processing Subsystem CALL CONFIGURE Screen ...
Страница 268: ...268 S HP892XX USRGUIDE manual confscrn fb Chapter 7 Configure Screen Field Descriptions ...
Страница 269: ...269 8 Signaling Decoder Screen ...
Страница 338: ...338 S HP892XX USRGUIDE manual decoscrn fb Chapter 8 Signaling Decoder Screen Tone Sequence Decoder ...
Страница 339: ...339 9 Duplex Test Screen ...
Страница 353: ...353 10 Signaling Encoder AF Generator 2 ...
Страница 435: ...435 11 Help Screen ...
Страница 437: ...437 12 I O Configure Screen ...
Страница 443: ...443 13 Message Screen ...
Страница 445: ...445 14 Oscilloscope Screen ...
Страница 456: ...456 S HP892XX USRGUIDE manual prinscrn fb Chapter 15 Print Configure Screen Field Descriptions ...
Страница 471: ...471 17 RF Analyzer Screen ...
Страница 482: ...482 S HP892XX USRGUIDE manual rfanscrn fb Chapter 17 RF Analyzer Screen Field Descriptions ...
Страница 483: ...483 18 RF Generator Screen ...
Страница 492: ...492 S HP892XX USRGUIDE manual rfgscrn fb Chapter 18 RF Generator Screen Field Descriptions ...
Страница 493: ...493 19 RX Test Screen ...
Страница 504: ...504 S HP892XX USRGUIDE manual servscrn fb Chapter 20 Service Screen Field Descriptions ...
Страница 519: ...519 22 Tests Screen ...
Страница 548: ...548 S HP892XX USRGUIDE manual testscrn fb Chapter 22 Tests Screen ROM Programs ...
Страница 549: ...549 23 TX Test Screen ...
Страница 551: ...551 Chapter 23 TX Test Screen Field Descriptions Field Descriptions Figure 145 The TX Test Screen txscrn wmf ...
Страница 561: ...561 24 Connector Key and Knob Descriptions ...
Страница 585: ...585 25 Modifications Accessories Manuals Support ...
Страница 605: ...605 Error Messages ...
Страница 618: ...618 S HP892XX USRGUIDE manual errormsg fb Error Messages ...