(d)
Park Control produces a voltage that is sent to the microcomputer. When an ILS frequency is selected, the computer output parks the RMI needle at the right wing point.
(4) KING RADIO KNR 6030 Receiver
(a) The VOR transmission is an RF carrier amplitude modulated by a 9960-Hz subcarrier to a nominal 30% depth of modulation. The subcarrier is in turn frequency modulated by a 30-Hz reference signal. The RF carrier is also amplitude modulated by a 30-Hz signal whose phase difference (with respect to the reference signal) is equal to the receiver's bearing from the VOR station. The RF carrier is also modulated with either speech or an identification signal to ensure that the proper VOR station is being received.
EFFECTIVITY
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(b)
The VOR signal is detected by the VOR/LOC antenna and demodulated by the VHF receiver before being sent to the digital phase detector. The digital phase detector computes the phase difference between the two 30-Hz signals and then the omnibearing (OB) word generator codes this difference into a digital 16-bit word. The microprocessor then uses the digital magnetic heading input from the synchro-to-digital processor to calculate the VOR output to the RMI driver. The microprocessor also uses the course select input from the OB synchro-to-digital processor to calculate the VOR deviation signal. The VOR deviation signal goes thru a digital-to-analog converter (DAC) before being output to the HSI. The microprocessor also generates the to/from signal associated with VOR deviation for display in the HSI.
(c)
A VOR flag is generated by the VOR processor when calculations of VOR bearing or VOR deviation cannot be made.
C. Functional Description, Glide Slope Mode Operation
(1)
COLLINS 51RV-2B Receiver
(a)
The UHF synthesizer takes the output of the VHF synthesizer, 50 KHz from the frequency standard, and the frequency control information and produces uniquely paired UHF glide slope injection frequencies. The localizer injection frequency together with the output of a vco (voltage controlled oscillator) are applied to a mixer. The difference frequency is divided to 50 kHz in the variable counter and compared to the kHz reference frequency.
(b)
The dc output of the phase detector controls the VCO to produce an output frequency which, when subtracted from the localizer injection frequency produces a multiple of 50 kHz. The output of the vco is tripled and applied to the first mixer in the glide slope receiver.
(c)
The G/S UHF receiver operates similarly to the VHF receiver. The glide slope rf from the glide slope antenna is applied via a bandpass filter to the first mixer. The first IF is amplifier and processed through a second conversion and applied to detector and AGC circuits. The audio output of the detector is applied to the glide slope instrumentation.
(d)
Discriminators in the glide slope instrumentation produce glide slope deviation signals which are applied to the pilots' instruments. The output of the discriminator is compared in integrity monitor circuits. The integrity monitor circuits produce the glide slope flag signal if a fault occurs in the glide slope circuits.
(2)
COLLINS 51RV4/4( ) Receiver
(a) The UHF synthesizer produces the UHF glide slope highside injection frequency for the first mixer in the glide slope receiver.
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