User's Manual

Model 1150A DVOR
6-12 Rev. - November, 2008
This document contains proprietary information and such information may not be disclosed
to others for any purposes without written permission from SELEX Sistemi Integrati Inc.
k. Read the field intensity value in Monitors>> Data>> Integrity data and subtract the reading from 0.0. The
change should be less than 1 dB.
l. Place this offset value in Monitors>> Configuration>> Offsets and Scale Factors for Monitor 1 and for
Monitor 2.
6.4.13
DME Keying Check
This procedure is used on systems where the DVOR is collocated with a DME.
a. Place the DVOR in normal.
b. Select (on VOR) RMS>>Commands>>Select Audio>Transmitter 1 Ident.
c. Place DME in normal.
d. Verify audible DME keying. Select (on SELEX-SI DME) RMS>>Commands>>Select Audio>Transmitter
1 Ident.
e. If keying is not detected or is not in synchronization with the DVOR check terminal board wiring and
connections.
6.4.14
DVOR Frequency Synthesizer Alignment
The following procedure must be used to properly align the Frequency Synthesizer Assembly for operation at a new
frequency. References to the 1A3A1 Frequency Synthesizer Assembly are for Transmitter 1 and references to the
1A3A11 Frequency Synthesizer are for DVOR Transmitter No. 2.
NOTE
The RF power level at 1A3A1J2 on the front panel of the Frequency Synthesizer Assembly can be
as high as +15 dBm. In the following step, use attenuators as appropriate for the frequency
counter used to properly protect any counter input ports.
a. Connect a frequency counter to 1A3A1J2, the SMA connector on the front panel of the Frequency
Synthesizer Assembly.
b. Turn on Tx 1.
c. Measure the output frequency of the 1A3A1J2 Frequency Synthesizer Assembly. If the measured
frequency is outside the Operational Tolerance of Table 4-1(c) then perform the following steps:
i. Remove power from the DVOR.
ii. Remove the Frequency Synthesizer 1A3A1 from the VOR cabinet.
iii. Connect the 1A3A1 Frequency Synthesizer Assembly to the DVOR with extender board.
iv. Apply power to the DVOR. Turn on Tx 1. Place Monitor in Bypass.
v. The 10.000 MHz TCXO (Y1) in the Frequency Synthesizer Assembly may be adjusted to correct
the operating frequency. Small adjustments can be made to Y1 with the R27 potentiometer to
achieve this. Once the TCXO is set the station frequency should be within the Initial Tolerance of
Table 4-1(c).
vi. Remove power from the DVOR.
vii. Replace the Frequency Synthesizer Assembly in the system cabinet.
viii. Apply power to the DVOR.
NOTE
Placing the Frequency Synthesizer Assembly on the extender board may cause VOR Monitor to
indicate an alarm condition. The alarm may be caused by carrier phase control loop unlock or
phase difference of the Carrier to Sidebands. There will be no effect on the frequency counter
readings taken at the test port output, J2 on the front panel of the Frequency Synthesizer
Assembly.
d. Connect a DMM to the carrier phase loop error voltage at TP1 on the 1A3A1 Frequency Synthesizer
Assembly front panel.
e. Log in to the PMDT and select Transmitters>> Configuration. Adjust Tx 1 Carrier PLL control from 0 to
100% to achieve 0.0 +/- 0.05 volts on TP1.