Cessna 400 Adf - Cessna TR182 1979 Pilot Operating Handbook

PILOT'S OPERATING HANDBOOK
SUPPLEMENT
CESSNA 400 ADF
(TYPE R-446A)
SUPPLEMENT
CESSNA 400 ADF
(Type R-446A)
SECTION 1
GENERAL
The Cessna 400 ADF is an automatic direction finder set which
provides continuous, visual bearing indications of the direction from
which an RF signal is being received. It can be used for plotting position,
for homing, and for aural reception of AM signals between 200 kHz and
1699kHz. In addition, a crystal-controlled, beat frequency oscillator (BFO)
permits coded identifier of stations transmitting keyed CWsignals (Morse
Code) to be heard.
The basic units of the Cessna 400ADF are a R-446AReceiver with dual
frequency selectors, a goniometer-indicator (IN-346A), a sense antenna
and a loop antenna. The receiver and goniometer-indicator are panel-
mounted units. The sense and loop antennas are mounted on the external
airplane surfaces. The goniometer-indicator presents station bearing in
degrees of azimuth. An automatic pointer-stow feature alerts the operator
to non-ADF operation by slewing the pointer to the 3:00 o'clock position
when the REC mode is selected. Operating controls and displays for the
Cessna 400 ADF are shown and described in Figure 1. The audio system
used in conjunction with this radio for speaker-phone selection is shown
and described in Section 7 of this handbook.
The frequency range of the Cessna 400ADF is electronically divided
into three bands: 200-399kHz, 400-799kHz, and 800-1699kHz. Frequency
spacing within each band is in 1-kHzincrements. The operating frequency
and band are selected by a four-section Minilever switch which displays a
digital readout of the frequency selected and supplies a binary code to
control the logic circuits within the set.
A
secondary (standby) operating
frequency is selected by another four-section Minilever switch. Frequency
control of the ADF is switched to the primary or the secondary operating
frequency by a toggle switch. The operating modes (ADF and REC) are
selected by individual pushbutton switches. Additional pushbutton
switches are used to select the BFO and to test signal reliability during
ADF operation.
1 October 1978
1
of 6