(3)  
Rotate mode switch on ADF control panel through ADF, ANT, and LOOP positions. Verify that panel and dial lights are illuminated for all three modes.

 (4)  
Select ADF-1 on flight interphone system audio selector panel.

 (5)  
Set mode switch to ANT.

 (6)  
Check that a local AM broadcast station in the 190-1800 kHz frequency range can be received loud and clear. Vary ADF system GAIN control (and gain control (if provided) on audio selector panel) to check that control of audio from station is smooth and audio can be adjusted to more than adequate level.

 (7)  
Set mode switch to LOOP. With LOOP control in maximum left position, check that applicable pointer needles on RMI's rotate CCW and the time for full 360-degree rotation is 10 seconds or less. Check that same occurs for right position of LOOP control except rotation is CW. Return mode switch to ANT position.

 (8)  
Set BFO switch to on position.

 (9)  
Tune ADF system to receive known low frequency range stations in 300-360 kHz range, and range station(s) in 190-399.5, 400-799.5, 800-1599.5, and 1600-1799.5 kHz ranges, as available.

 (a)  
Tune for BFO zero beat with carrier frequency of range station(s) selected. Detune slightly up from station zero beat with BFO in off position and check that 1020 Hz range station identification code signal can be heard clearly. Return BFO control to on position. Repeat with ADF mode selected.

 (b)  
With ANT mode selected, retune to zero beat and check that frequency readout on control panel checks within 1% of listed frequency for stations selected. Repeat with ADF mode selected.

 EFFECTIVITY

 AF 101-151; IB 405;  CONFIG 1 LH 001-010; SN 301-302  10 Page 501  Dec 25/87

34-57-00
ADF RECEIVERS

ADF SENSE ANTENNAS AND COUPLERS LOCATED AFT OF WHEEL WELLS ON AIRPLANES NOT INCORPORATING SB 34-2114.
ADF SENSE ANTENNAS AND COUPLERS LOCATED FWD OF RH WHEEL WELL ON AIRPLANES INCORPORATING SB 34-2114.
ADF SENSE ANTENNA COUPLERS ARE MOUNTED DIRECTLY TO FAIRING J-BEAM ON AIRPLANES INCORPORATING SB 34-2195.
BEAT FREQUENCY  MODE 
OSCILLATOR SWITCH  FREQUENCY  SELECTOR 
AND TONE CONTROL  INDICATOR  SWITCH 

GAIN CONTROL
LOOP ANTENNA CONTROL
RADIO MAGNETIC INDICATOR

CONTROLS
ADF CONTROL PANEL

ADF System Component Location
Figure 501

EFFECTIVITY

 AF 101-151; IB 405;  CONFIG 1 LH 001-010; SN 301-302  09 Page 502  Dec 25/87

34-57-00
 (c)  
Select ANT, ADF, and LOOP positions on mode switch and check that on stations selected above, an approximate 1000 Hz BFO beat note can be heard for each position. BFO control should be set to dot-to-dot position during this test (c).

 (d)  
Select LOOP mode. Rotate LOOP control left and right and check that BFO signal is minimum when applicable pointer needle on RMI's is at 0 or 180 degrees from station bearing.

 NOTE:____ Narrow needle is used with ADF No. 1 system (Captain's),
 and wide needle with ADF No. 2 system (First
 Officer's).
 (e)  Check that pitch of BFO signal increases when BFO control
 is rotated CW while receiving a range station in ANT, ADF,
 and LOOP modes.
 (f)  Vary GAIN control when BFO control is set to dot-to-dot
 position during ANT, ADF, and LOOP modes.  Loudness of BFO
 signal should vary smoothly.  GAIN control varies audio level
 in ANT mode, and received RF in ADF and LOOP modes.

 (10)
 Set mode switch to ADF.

 (11)
 Turn BFO switch off.

 (12)
 Tune ADF system to receive a known standard broadcast station in 550 kHz to 830 kHz range. Verify loud, clear reception of transmission.

 (13)
 Tune ADF system to receive AM broadcast stations in 190-399.5, 400-799.5, 800-1599.5, and 1600-1799.5 kHz frequency ranges. Check for loud and clear reception in ANT and ADF modes for each station selected.

 (14)
 Select ADF mode.  Check that both RMI's indicate in tolerance bearing to selected station.

 (15)
 Set mode selector switch to LOOP.

 (16)
 Use LOOP control switch to drive RMI indicator needles 170 degrees away from station bearing.

 (17)
 Select ADF mode and verify that indicator needles return smoothly to station bearing.

 (18)
 Set mode selector to LOOP.

 (19)
 Set LOOP control switch to L and verify CCW needle rotation.
　
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