SECTION III
INSTRUMENTATION AND AVIONICS
MODEL 560
CONTROLS AND INDICATORS
Tuning of the COM radios is accomplished by three methods. The first method, discussed below, also
provides methods to store frequencies in the memory locations. This is considered the "normal" method.
Storing of the frequencies while tuning is not required, however, and is discussed there only because it
may be convenient to store the frequencies as they are used for possible later use. The second method is
"direct tuning", and the third is remote tuning through the Auxiliary COM 1/NAV 2 control display unit
control head which may be used when only battery power is available or desired, or in case of emergency.
Operation of the Auxiliary COM 1/NAV 2 control display unit control head is discussed at the end of the
COM section.
Normal, or preselect tuning of the COM radios is accomplished in the following manner: Press the line
key next to the second COM frequency line displayed on the RMU. The amber box will move to that
position if it is not already there; set the desired frequency by means of the concentric tuning knobs at the
bottom of the RMU; press the upper left button on the RMU bezel (the one with vertical arrows), which will
switch the pretuned frequency with the active frequency. When a frequency is preselected (set in the
second line), it may result in the changing of a frequency which was identified by MEMORY, plus a number
from 1 to 12, below the active frequency. The prior number has been stored in memory and the imposition
of the second frequency over it is only temporary (which is identified TEMP) and will not result in the new
frequency being stored in the memory unless the STO button is pressed before the frequency is transferred
to the active location (top line). In this case, the word TEMP will be replaced by the word MEMORY plus
the memory position number. The pilot may progress through all 12 of the memory locations by pressing
the line key near the line identified by TEMP or MEMORY in the COM box (upper left hand corner), which
will move the amber box to surround that line. Turning either the large or small tuning knob will then select
each memory space sequentially, showing the frequency stored there in blue on the line above the
MEMORY annunciator line. Vacant memory locations will not appear. When the last occupied memory
location is selected, the frequency shown on the second line, which was a temporary frequency in memory,
will again be shown to occupy that space, plus the word TEMP, indicating that it is not stored in MEMORY.
When progressing through the stored memory locations, the frequency in the memory location being
displayed can be transferred into the active position (tuned) simply by pressing the upper button (the one
with the vertical arrows).
If the pilot desires to view all of the stored frequencies at once, he may press the PGE (page) button
at the bottom of the RMU and the active frequency, with a maximum of six stored frequencies, will be
displayed along with the number of their memory location. Pressing the line key adjacent to the MORE
annunciator will advance the page to show the remaining frequencies with their location numbers of 7
through 12. If it is desired to insert a frequency in any particular location on these pages, move the cursor
to that location by pressing the line key next to the desired memory location and the tuning knob will control
that selection. The memory locations must be filled sequentially, i.e., blanks cannot be left open. If
memory location eleven is vacant, for instance, and an attempt is made to store a frequency in location
twelve, the word “can’t” will appear in amber at the bottom of the page. It is not necessary to push STO to
store the frequency. If deletion of a stored frequency is desired, press the line key adjacent to that memory
location and press the line key adjacent to the DELETE annunciator. Higher memory locations will move
down to fill the vacant space. If the pilot desires to place a frequency in a particular memory location, press
the line key at that location to move the amber box there; press the line key at the INSERT location. The
frequencies at the selected location and at higher location numbers will move up one location. The
frequency in the selected location may then be modified and it will be stored.
If all the memory locations on the first memory page are not filled, the second memory page cannot
be accessed. Direct tuning of the COM radio is accomplished by selecting the cursor (amber box) to the
COM preset location (second frequency line) and pressing the line key at that position for a minimum of
three seconds. The preset frequency will disappear and the cursor will move and enclose the active
frequency. Direct tuning is then available. Preset tuning may be restored by pressing the same button
again.
An additional feature provided by the SRZ-850 integrated system is stuck microphone protection. The
COM transmitter has a two-minute timer which cuts off transmission after that time has elapsed if the MIC
key has not been released. A short warning tone is sounded a few seconds before the automatic shutoff.
When the microphone cutoff has been activated at the two-minute limit, a MIC STK warning in red will be
annunciated in the upper left corner of the RMU.
I
3-18 Configuration AA 56OMB-01
To Next Page