2.3 OPERATING F REQUENCIES VS ICAO CHANNEL DESIGNATORS
For all test frequencies listed in test setups in this report, the ICAO Channel Identification
developed for the 8.33 kHz channels is used. The channel identification will not
necessarily reflect the actual operating frequency. Table 4.7-1 shows the relationship
between ICAO Channel Identification, actual operating frequency, receiver bandwidth,
and ARINC 429 frequency control word. NOTE: Narrow Band (NB) is selectivity for
8.33 kHz channels and Wide Band (WB) is selectivity for 25 kHz channels.
Table 4.7-1
Frequenc y (MHz)ICAO Cha n ne l
Name
ARINC 429
Control Word
Content
ARINC 429
Control Word
Label
Rece iver IF
Bandwidth
automatically
selected b y
unit
• In transmit mode, the antenna output shall be terminated in 50
ohm load and the sidetone audio output terminated in 600 ohm
load. In receive mode, receiver and data audio outputs are
terminated in 600 ohm load.
• All receiver RF levels are in dBm at UUT antenna input.
• Upper limit of operation at ICAO channel 136.990 applies for
some units. Disregard operation beyond this frequency in any
alignment or tests wh ere frequencies exceeding this limit are
specified.
• Connect TX_Mode_Indicator (VHF-4000 Pin 47, VDL-2000 Pin 3)
to 27.5 Vdc th rough a 270 ohm, ½ watt load.
5.1 STANDARD DISCRETE CONFIGURATION
The “Standard Discrete Configuration” is defined as the following configuration of the input discretes:
Open
RIU_Installed_Sel43NAOpen (RIU not installed)
All_Call_Dsbl_Set44NAOpen (All -Call enabled)
Voice/Data_Sel4517Open (Voice m ode)
Burst_Tune_Sell49NAOpen (Continuous tuning)
ARINC/CSDB Selec t50NAOpen (ARINC-429 control selected)
Port_C_Sel51NAOpen (ARINC 429 In put Port C not
selected)
RX_Comp_Dsbl_Sel52NAOpen (Receive compressor disabled)
Port_A/B_Sel55NAOpen (ARINC 429 In put Port B
selected)
Unit_ID_A_Sel
Unit_ID_B_Sel
56
62
15
18
Open (All-Call enabled *)
Open
WOW_Sel5714Open (Weight on Wheels not selected)
Data_Load_Enbl_Sel6129Open (Data Load disabled)
SYSTEM_ON_FNA27Gnd (Tran sceiver On)
5.2 STANDARD RF GENERATOR CONFIGURATION
The “Standard RF Generator Configuration” is defined as follows:
Generator set to the frequency defined at time of reference, amplitude modulated
by a 1 kHz sine wave at a modulation level of 30%, and a RF level of –47 dBm.
All test steps are performed using continuous tuning on the low speed ARINC 429 control bus
429_Input_Port_B (Pins 3 and 4). The control words are labels 030 for 25 kHz channels & 047 for 8.3
kHz channels.
Calibration and TFM parameters are set using the high-speed maintenance input bus MAINT_IN (Pins 9
and 10) and output port MAINT_OUT (Pins 13 and 14). The control word is label 277 (See Appendix for
format).
5.3.1.2 VDL-2000
All test steps are performed using continuous tuning on the high-speed ARINC 429 maintenance input bus
429MAINT_IN (pins 1 and 32). The control words are labels 030 for 25 kHz channels & 047 for 8.3 kHz
channel s .
Calibration and TFM parameters are also set using the high-speed ARINC 429 maintenance input bus
429MAINT_IN (pins 1 and 32). The control word is label 277 (See Appendix for format).
5.3.2 Standard Data Configurations
• The “Standard 25 kHz ARINC Configuration” is defined as follows:
Octal label 047 (8.33 kHz label) s et to NCD.
Transmit the control data on label 030 (Oct) every 200 ms.
The tuning channel will be defined at the time of reference to this definition.
The SSM is set to 11 (squelch disabled).
SDI set to 00 (All call).
• The “Standard 8.33 kHz ARINC Configuration” is defined as follows:
Octal label 030 (25 kHz la bel) set to NCD.
Transmit the control data on label 047 (Oct) every 200 ms.
The tuning channel will be defined at the time of reference to this definition.
The SSM is set to 11 (squelch disabled).
SDI set to 00 (All call).
5.4 TEST SEQUENCE
If the UUT has never been aligned then all alignment steps must be performed in sequence. For realignment of UUT as a result of a repair action or modification, perform only alignment steps of circuits
that have been effected by repair action or modification. Checksum will be automatically updated
whenever FLASH memory is updated.
Connect main connector plug from test station to UUT.
Apply 27.5 ± 0.5 Vdc to the power input.
VHF-4000, power pins 58, 64 and ground pins 59, 65.
VDL-2000, power pins 10, 11 and ground pins 8, 9.
Wait 30 seconds for the unit to complete power on testing.
The VHF4000 or VDL2000 may be aligned per Section 6.3 Alignment Procedures or with the automatic
alignment system (CATS-21) executing DGS-005.
6.1 SOFTWARE LOAD PROCEDURE
Load the desired top-level software using the data loader capability of the VHF-4000 or the boundary scan
interface.
6.2 CALIBRATION AND TFM PARAMETERS
The VHF-4000 uses electronic alignment for circuits that use values for various parameters stored in
FLASH memory. TFM parameters are those that require different values depending upon temperature,
frequency or mode. Calibration parameters are those that are the same for all temperature, frequency, and
mode.
6.2.1 Initialization of Calibration Parameters
Store into FLASH memory the hex values for calibration parameters listed in the following table or the
nominal value (nominal values derived from trend data).
Calibration Parameter#Applicable
Combined Au dio Level Adju st43Rx4268 level adjust for combin ed audio Rx output
Digital Audio Lev el Adju st44Rx23E7level adjust for digital audio Rx output
Rx Compres sor Threshold45Rx250F input level threshold for receiver com pressor
Carrier Squ el ch Mute Thresh old46Rx7FFF Carrier Squel ch mut ing upper limit
Carrier Squelch Unmute Threshold47Rx7FFF Carrier Squelch unmuting upper limit
25 kHz Noise Squelch Mute Threshold 48Rx7FFF 25 kHz Noise Squelch muting upper limit
25 kHz Noise Squelch Unmut e
Thres hold
8.33 kHz Noise Squ elch Mute
Thres hold
8.33 kHz Noise Squ elch Unmut e
Thres hold
138.6 MHz N oise Squelch Mute
Thres hold
138.6 MHz N oise Squelch Unmute
Thres hold
Digital Audio Sideton e Level Adjus t54Tx2C76 level adjust for digital audio sideton e output
Combined Au dio Sideton e Lev el Adjust 55Tx1C39 level adjust for combined audio sidetone out
Low Volt age Scalin g Threshold56Tx07D0 low volt limit for signal scalin g in transmits
VSWR Sc a ling Thr e sh old57Tx4E20 VSWR l im it for signal scalin g in tr ansmits
Anal og Tx Compr essor Threshol d58Tx6DElevel to begin analog Tx signal compres sion
Digital Audio Tx Compressor Thr eshold 59Tx07FF level to begin digital Tx signal compression
Tx Pow er Upper Threshol d for all but
Mode 2
Tx Pow er Lower Threshol d for all but
Mode 2
Tx Power Upper Thres hold for Mode 2 62Tx07FF V Fwd high limit for Mode 2 Tx faults
Tx Pow er Lower Threshol d for Mode 2 63Tx0000 V Fwd l ow limit for Mode 2 Tx faults
VSWR Fault Thr eshold64Tx7FFF VSWR limit for reporting of faults
PA Over Temper ature Threshold65Tx0783 PA temperatur e limit at which Tx is aborted
+3.3 VDC Upper Thr eshold66Rx/Tx09C5 faul t upper limit f or +3.3 VDC input value
+3.3 VDC Lower Thr eshold67Rx/Tx0698 fault lower limit for +3.3 VDC input value
+8.0 VDC Upper Thr eshold68Rx/Tx 0A7A f aul t upper limit f or +8.0 VDC input value
+8.0 VDC Lower Thr eshold69Rx/Tx0649 fault lower limit for +8.0 VDC input value
-8.0 VDC Upper Thr eshold70Rx /Tx0965 fault upper limit f or -8.0 VDC input valu e
-8.0 VDC Lower Threshold71Rx/Tx05A3 fault lower limit for -8.0 VDC input value
+5.0 VDC Upper Thr eshold72Rx/Tx 0CF6 f aul t upper limit f or +5.0 VDC input value
+5.0 VDC Lower Thr eshold73Rx/Tx06FA faul t lower limit for +5.0 VDC input value
+15.0 VDC Upper Thr eshol d74Rx/Tx0A79 fault upper limit for +15.0 VDC input value
+15.0 VDC Lower Thr eshol d75Rx/Tx06FB Fault low er limit for +15. 0 VDC input value
Tx Timeout Thr eshold76Tx3FFFlimit at which Tx is aborted
TFM Tem per ature Boundary A77Rx/Tx01C1 Sets TFM temperature zones 1 & 2 boundary
TFM Tem per ature Boundary B78Rx/Tx0364 Sets TFM tem peratur e zones 2 & 3 boundary
TFM Tem per ature Boundary C79Rx/Tx0508 Sets TFM temperature zones 3 & 4 boundary
TFM Temperature Hyste resis80Rx/Tx33Hysteresis for descending temp zone tra nsits
VSWR Scalin g Coefficient81Tx571CPower reduct ion to apply for VSWR scaling
SELCAL Audio Lev el Adjust82Rx5654 Level adjust for SELCAL audio DAC ou t put
Low V IQ Phase Adj. Upper Threshol d 83Tx0000
Low V IQ Phase Adj. Lower Threshol d 84Tx0000
SW AGC Selftest Limit On Threshold85Rx7FFF SW AGC level max limit with signal present
SW AGC Selft est Limit Off Threshol d86Rx0000 SW AGC level min limit with signal absent
HW AGC Selft est Limit On Threshol d87Rx0000 HW AG C level max limit with signal present
HW AGC Selft est Limit Off Threshol d88Rx7FFF HW AGC level min limit with signal absent
Trans f er Fault Tone Level Adj.89Rx/Tx12CAudio level of fault
D8PSK Low Volt age Scalin g Threshold 90Tx0000
I _Q _Ref91TX0000 Not Used
Spare_192N/A0000 Not Used
Spare_293N/A0000 Not Used
Spare_394N/A0000 Not Used
Spare_495N/A0000 Not Used
Value
Notes
(hex)
28V val. to start Low Voltage IQ Phase Adjust
(TBD
new
value
28V val. to end Low Voltage IQ Phase Adjust
(TBD
new
value
Low volt limit for signals scaling in transmit in D8PSK
(TBD
modes.
new
value)
6.2.2 Initialization of TFM Parameters
Store into FLASH memory the hex values for TFM parameters listed in the following table or the nominal
value for 118 MHz (nominal values derived from trend data).
I Phas e Adjust1Tx0000 n ormal setting for I phase adjustm ent DACs
Q Phas e Adjust2Tx2048 n ormal setting for Q phase adjustm ent DACs
Simulcomm 03RxFFsets SCOM Thresh DAC when Simulcomm discretes
Simulcomm 14RxFFsets SCOM Thresh DAC when Simulcomm discretes
Simulcomm 25RxFFsets SCOM Thresh DAC when Simulcomm discretes
Simulcomm 36RxFFsets SCOM Thresh DAC when Simulcomm discretes
Preselect or 17Rx/Tx0000 sets Pres el _1 DAC
Preselect or 28Rx/Tx0000 sets Pres el _2 DAC
Preselect or 39Rx/Tx0000 sets Pres el _3 DAC
Preselect or 410Rx/Tx0000 sets Presel_4 DAC
PA Drive Bias for D8PSK11Rx/Tx0000 sets PA Drive Bias DAC when in ARINC 750 Mode 2
PA Drive Bias for all but D8PSK12Rx/Tx0000 sets PA Drive Bias DAC when not in ARINC 750
PA Final Bias for D8PSK13Rx/Tx0000 sets PA Final Bias DAC when in ARINC 750 Mode 2
PA Final Bias for all but D8PSK14Rx/Tx0000 sets PA Final Bias DAC when not in ARINC 750
D8PSK I Channel G ain15Tx0000 sets I chann el gain for D8PSK tr a nsmission s
D8PSK Q Channel G ain16Tx0000 sets Q channel gain for D8PSK tr ansmissions
AM I Chann el Carrier Power17Tx0000 sets I chann el offset (carrier pow er) for AM
AM Q Chann el Carrier Power18Tx0000 sets Q channel offset (carrier pow er) for AM
D8PSK I Channel Carr ier Null (off set)19Tx0000 sets I chann el offset (carrier null ) for D8PSK
D8PSK Q Channel Carr ier Null (off set) 20Tx0000 sets Q channel offset (carrier null) for D8PSK
Mode A I Channel Carrier Power
(offset)
Mode A Q Channel Carrier Power
(offset)
AM I Chann el Mod % (gain)23Tx0000 Sets I channel mod % (gain) for AM Tx
AM Q Chann el Mod % (gain)24Tx0000 Sets Q channel mod % (gain) for AM trans m ission s
Mode A I Channel Mod % (gain)25Tx0000 Sets I channel mod % (gain) for Mode A
Mode A Q Channel Mod % (gain)26Tx0000 Sets Q channel mod % (gain) for Mode A
AM Voice Rx Audio Phase Shift27Rx0000 Adjusts phase of Rx audio output relat ive to input RF
D8PSK Qu adr ature Mismatch28Tx0000 compensates transmit sign al for feedback modul ator
Rx Synthesizer Adjust29Rx55CN count for receiver synthes iz er tuning
Tx Synth esizer Adju st30Tx8CCN count for transmitter synthesizer tuning
I Low Voltage Phase Adju st31Tx0000 normal setting for I phase adjustment DACs
Q Low Voltage Phase Adju st32Tx07FF normal setting for Q phase adjustment DACs
Mode 2 –90.5 dBm Level33Rxnor m al setting for –90.5 dBm Mode 2 Rx level
Mode 2 –91.5 dBm Level34Rxnor m al setting for –91.5 dBm Mode 2 Rx level
AM I Chann el Carrier Null (offset)35Tx07FF sets I channel offset null for AM transmissions
AM Q Chann el Carrier Null (offset)36Tx07FF sets Q ch annel offset null for AM transmissions
Spur Suppr ession N oise Level37Tx8.3 kHz synthesiz er spur adj.
Spare 638N/A
Spare 739N/A
Spare 840N/A
Spare 941N/A
Spare 1042N/A
21Tx0000 sets I channel offset (carrier pow er) for Mode A
22 Tx0000sets Q chann el offset (carrier pow er) for Mode A
9) Ground the PTT and vary TFM parameter #1 & #2 (Q phase & I adjust) u p or down
from initial value as necessary to null the Q detector voltmeter reading. Final value
must be less than TBD.
Note: The I& Q Phase Adjust values are calculated as a function of the phase angle
using the following formula:
Q bits = ((1.25 x sine (Angle) + 1.25)) / (2.5/4095)
I bits = ((1.25 x cos (Angle) + 1.25)) / (2.5/4095)
10) Unground the PTT.
11) Store the values for TFM parameter #1 and #2 in Flash memory.
6.3.6 +20 V Transmitter Phasing Adjustment [Tx TFM]
1) Set Standard ARINC Configu ration at current frequency.
2) Set Standard Discrete Configuration.
3) Verify power supply input voltage is 20.0 +/- 0.2 Vdc.
4) Apply 0.7 Vrms, 1 kHz tone to Microphone Audio input.
5) Set I & Q channel carrier offset to 0
6) Set Q Channel Gain to 0.
7) Set I Channel Gain to get 4 – 6 watts RF output power
8) Monitor the Q_Detector Output of the RF Card
9) Ground the PTT and vary TFM parameter #30 & #31 (LV Q phase & I adjust) up or
down from initial value as necessary to null the Q detector voltmeter reading. Final
value must be less than TBD.
Note: The I& Q Phase Adjust values are calculated as a function of the phase angle
using the following formula:
Q bits = ((1.25 x sine (Angle) + 1.25)) / (2.5/4095)
I bits = ((1.25 x cos (Angle) + 1.25)) / (2.5/4095)
10) Unground the PTT.
11) Store the values for TFM parameter #1 and #2 in Flash memory.
6.3.7 Preselecto r Adjust me nts [Rx Cal]
1) Set Standard ARINC Configuration at current frequency.
2) Set Standard RF Generator setting at current frequency.
3) Set Standard Discrete Configuration.
4) Moni tor the combined audio output.
5) Adjust the generator RF level to give approximately 12 dB SINAD ratio.
6) Iteratively adjust TFM parameters #7 –10 from initial values for the best SINAD while reducing the
RF level to maintain 12 dB SINAD. The final SINAD after adjustment must be at least 8 dB with –
103 dBm input RF level.
7) Store the values used for TFM parameters #7 - #10 in Flash memory.
6.3.8 Analog Voice/Data Unmodulated Transmitter RF Power [Tx TFM]
1) Set Standard ARINC Configu ration at current frequency.
2) Set Standard Discrete Configuration.
3) Set TFM parameters #17 & #18 (AM I and Q channel carrier power) to 2048 (Dec).
4) Ground the PTT and increment TFM parameters # 17 until the RF wattmeter
indicates 10 watts +/- 1 watt.
1) Set Standard ARINC Configu ration at current frequency.
2) Set Standard RF Generator setting at current frequency.
3) Set Standard Discrete Configuration.
4) Set rear connector simulcomm discretes to 01(VHF4000 Pins 42 open and 46
ground, VDL Pins 16 open and 34 ground).
5) Set the generator RF level to -10 dBm and 90% modulation.
6) Monitor the AGC_Level output of the RF Card.
7) Decrease TFM parameter # 4 un til the AGC_Level decreases at least 2% - 4% from
the reading in step 6.
8) Store the value used for TFM variable #4 in the Flash memory.
9) Find value at 118 MHz channel and use value for 119-125 MHz channels.
10) Find value at 126 MHz channel and use value for 127-136 MHz channels.
6.3.11 Analog Voice/Data Transmitter Modulation [Tx TFM]
1) Set Standard ARINC Configu ration at current frequency.
2) Set Standard Discrete Configuration.
3) Apply a 0.4 Vrms audio signal at 1.0 kHz to th e microphone input.
4) Ground the PTT and simultaneously increment TFM parameters #23 and 24 (AM I
and Q Channel Mod) to obtain modulation of the negative peaks at 90 +/- 3 %.
5) Unground the PTT.
6) Store the value used for TFM parameters #23 and #24 in the Flash memory.
1) Set the UUT discrete inputs to “standard discrete configuration”.
2) Set the ARINC data to “Standard 25 kHz ARINC Configuration” on channel 118.500.
3) Connect 50 ohm load to antenna cable
4) Set TFM parameters #18 and 19 (D8PSK I and Q channel offset) and #15 and 16 (D8PSK Channel
Gains) to $00 to set transmitter power to 0 watts.
5) Set TFM parameters #12 and #14 (PA drive bias and final driver bias) to $0000.
6) Ground the PTT (VHF-4000 pin 41, VDL-2000 pin 35), and monitor the input current to the UUT.
7) Adjust TFM parameter #12 until the current increases by 500 mA ± 50 mA over the original value.
8) Adjust TFM parameter #14 until the current increases by an additional 1500 mA ± 50 mA over the
value in step 5.
9) Un gr ou nd the PT T.
10) Store the values used for TFM parameters #12 and #14 at 118.500 in 18 FLASH memory location up
to 136.500 MHz for the VDL-2000 and 151.5 MHz for the VHF-4000.
6.3.16.2 MODE 2 CARRIER NULL
1) Set the UUT discrete inputs to “standard discrete configuration”.
2) Tune the UUT to C hannel 118.500.
3) Set TFM parameters # 15 and 16 (D8PSK I_Channel Gain and Q_Channel Gain) to $00.
4) Set TFM parameters # 18 and 19 to mid-scale: $800.
5) Ground the PTT line (Pin 41 VHF-4000, Pin 35 VDL-2000), and adjust TFMs # 18
and 19(I_Offset and Q_Offset) alternately to null the carrier as detected on a
selective measuring receiver or power meter. The null shall be less than -15 dBm at
the sampled port.