Vertex Standard VX-177 manual DCS Code Inversion

Page 67

MISCELLANEOUS SETTINGS

DCS CODE INVERSION

The DCS system was first introduced in the commercial LMR (Land Mobile Radio) ser- vice, where it is now in widespread use. DCS is sometime referred to by its different pro- prietary names, such as DPL® (Digital Private Line®, a registered trademark of Motorola, Inc.).

DCS uses a codeword consisting of a 23-bit frame, transmitted (subaudible) at a data rate of 134.4 bps (bit/sec). Occasionally, signal inversion can result in the complement of a code to be sent or received. This prevents the receiver’s squelch from opening with DCS enabled, as the decoded bit sequence would not match that selected for operation.

Typical situations that might cause inversion to occur are:

￿Connection of an external receiver preamplifier.

￿Operating through a repeater.

￿Connection of an external linear amplifier.

Note that code inversion does not mean that any of the above listed equipment is defective!

In certain amplifier configurations, the output signal (phase) is inverted from the input. Small signal or power amplifiers having an odd number (1, 3, 5, etc.) of amplification stages may result in inversion of a transmitted or received DCS code.

While under most circumstances this should not occur (amplifier designs and industry standards take this into account), if you find that your receiver squelch does not open when both you and the other station are using a common DCS code, you or the other station (but not both) can try the following:

1. Press the [F] key, then press the [0(SET)] key to enter the Set mode.

2. Rotate the DIAL knob to select Set Mode Item 14: DCS.N/R.

3. Press the [F] key momentarily, then rotate the DIAL knob to select one of the following modes: T/RX N: Encoder, Normal; Decoder, Normal

RX R: Encoder, Normal; Decoder, Reverse (Inverted)

TX R: Encoder, Reverse (Inverted); Decoder, Normal

T/RX R: Encoder, Reverse (Inverted); Decoder, Reverse (In- verted)

4.When you have made your selection, press the PTT switch to save the new setting and exit to normal operation.

5.Remember to restore the default setting to “T/RX N” (Encoder; Normal, Decoder; Normal) when done.

VX-177 OPERATING MANUAL

65

Image 67
Contents Yaesu Europe B.V Vertex StandardContents General Description Supplied Accessories Accessories & OptionsAvailable Options Controls & Connectors TOP & Front Panels Controls & Connectors LCD PTT Push To Talk Switch Controls & Connectors Side PanelMoni Switch Press F + KEY Controls & Connectors Keypad FunctionsOne step or moves the memory Antenna Installation Installation of AccessoriesInstallation of FNB-83 Battery Pack LOW Battery Indication Battery ChargingInstallation of FBA-25A Alkaline Battery Case Option Belt Clip InstallationInterface of Packet Tncs Adjusting the Audio Volume Level Switching Power on and OFFOperation Squelch Adjustment Tuning DialFrequency Navigation Scanning Direct Keypad Frequency EntryTransmission Changing the Transmitter Power LevelKeyboard Locking Advanced OperationDisabling the Keypad Beeper KEYPAD/LCD IlluminationRF Squelch Checking the Battery VoltageRepeater Shifts Repeater OperationAutomatic Repeater Shift ARS Manual Repeater Shift Activation Changing the Default Repeater ShiftsChecking the Repeater Uplink Input Frequency VFO Split ModeRepeater Operation Ctcss Operation CTCSS/DCS/EPCS OperationDCS Operation Tone Search Scanning Epcs Enhanced Paging & Code Squelch Storing the Ctcss Tone Pairs for Epcs OperationActivating the Enhanced Paging & Code Squelch System CTCSS/DCS/EPCS Bell OperationTone Calling 1750 HZ Split Tone OperationStoring Independent Transmit Frequencies Odd Splits Memory ModeMemory Storage Home Channel Memory Memory RecallLabeling Memories Deleting Memories Memory Offset TuningMemory Bank Operation Assigning Memories to a Memory BankMemory Bank Recall Removing Memories from a Memory BankMoving Memory Data to the VFO Memory only ModeVX-177 Operating Manual Scanning Setting the Scan-Resume TechniqueProgrammed VFO Scan Manual VFO ScanVFO Scanning Memory Scanning How to Skip Omit a Channel during Memory Scan OperationPreferential Memory Scan Memory Bank Scan Programmable Band Limit Memory Scan PMS Priority Channel Scanning Dual Watch VFO PriorityMemory Channel Priority Home Channel PriorityVFO-VFO Dual Watch Priority Revert ModeBand Edge Beeper Automatic Lamp Illumination on Scan StopVX-177 Operating Manual Emergency Channel Operation Emergency FeatureEmergency Automatic ID EAI Feature Emergency Feature Smart Search Operation Setting the Smart Search ModeStoring Smart Search Memories Internet Connection Feature Internet Connection Feature Basic Arts Setup and Operation Arts Alert Beep Options Arts Polling Time OptionsCW Identifier Setup Manual Dtmf Tone Generation Dtmf OperationDtmf Autodialer To send the telephone number Storing the 3-digit code for the Dtmf Pager Operation Dtmf Pager Operation Requires Optional FTD-7Activating the Dtmf Pager Storing the ANI code Activating the ANI featurePassword Miscellaneous SettingsChanging the Channel Steps Programming the KEY AssignmentsTX Battery Saver Receive Battery Saver SetupAutomatic POWER-OFF APO Feature Disabling the TX/BUSY IndicatorBusy Channel LOCK-OUT Bclo Transmitter TIME-OUT Timer TOTDCS Code Inversion Changing the TX Deviation Level Reset Procedures Try again CloningVX-177 Operating Manual ARS SET Menu ModeNET CTCSS/DSC/DTMF/EPCS Setting ANI Set Mode Item 4 ARS Set Mode Item 1 APOSet Mode Item 2 AR BEP Set Mode Item 3 AR INTSet Mode Item 11 CW WRT Set Mode Item 8 BSY.LEDSet Mode Item 9 CLK.SFT Set Mode Item 10 CwidSet Mode Item 20 EDG.BEP Set Mode Item 17 DT WRTSet Mode Item 18 ECS.CDR Set Mode Item 19 ECS.CDTSet Mode Item 25 Lamp Set Mode Item 22 I NETSet Mode Item 23 INT CD Set Mode Item 24 INT MRSet Mode Item 30 Pswd Set Mode Item 27 M/T-CLSet Mode Item 28 Name Set Mode Item 29 NM WRTSet Mode Item 36 PRI.RVT Set Mode Item 33 REV/HMSet Mode Item 34 RF SQL Set Mode Item 35 RPT.MODSet Mode Item 42 Skip Set Mode Item 39 SCN MDSet Mode Item 40 SCN.LMP Set Mode Item 41 ShiftSet Mode Item 47 TOT Set Mode Item 44 SQL.TYPSet Mode Item 45 Step Set Mode Item 46 TN FRQSet Mode Item 54 ANI.WRT Set Mode Item 51 WID.NARSet Mode Item 52 EAI Set Mode Item 53 ANIGeneral SpecificationsInstallation of the FTD-7 Dtmf Paging Unit Option Declaration by Manufacturer 0511X-0K