TM 11-5840-281-12-1
4-28. CIRCUIT ALINEMENT. (CONT)
CURSOR ALINEMENT (CONT)
Height-Finder Cursor
The height finder cursor, which represents a straight horizontal line in space, is calibrated against two points of intercept
using scan angles of elevation antenna. One point of intercept is at 2 miles, where scan angle from horizontal is 1.41
degrees and altitude above horizontal is 300 feet. The second point is at 10 miles, where scan angle from horizontal is
13.8 degrees and altitude above horizontal is 15,000 feet. Two personnel are required to perform this procedure: one at
radar site and one at receiver-transmitter site.
1.
Ensure all controls and switches are in positions indicated in Preliminary Operating Procedure (para 2-5).
2.
On pulse generator, place EL CURSOR switch to HF position and SCAN MODE switch to 350 EL position.
3.
Set ALTITUDE control on pulse generator so field elevation is indicated in ALTITUDE indicator window.
4.
Disengage ALTITUDE control by pressing and holding drive shaft on right side of indicator window. Rotate
ALTITUDE control fully counterclockwise. Release drive shaft to engage altitude indicator.
NOTE
ALTITUDE indicator window now indicates elevation of field when ALTITUDE control is fully
counterclockwise.
5.
On receiver-transmitter main power panel, place SCAN and HV switches to OFF position.
6.
At radar site, install clinometer on elevation antenna clinometer mount, Clinometer Installation (para 4-21).
7.
Adjust clinometer to indicate elevation angle of 1.41 degrees, then manually rotate elevation antenna until
bubble level gives level indication.
8.
On pulse generator, alternately place ANGLE VOLTS switch into EL and OPERATE positions. Ad- just ART
ANGLE V control until artificial sweep trace coincides with operate sweep trace on elevation display. Record
ART ANGLE V dial indication that represents 2-mile intercept setting.
9.
Adjust clinometer to indicate 13.8 degrees, then manually rotate elevation antenna until bubble level gives level
indication.
10.
Alternately place ANGLE VOLTS switch on pulse generator in EL and OPERATE positions. Adjust ART ANGLE
V control until artificial sweep trace coincides with operate sweep trace on elevation display. Record ART
ANGLE V control dial indication that represents 10-mile intercept setting.
11.
On receiver transmitter main power panel, place SCAN on HV switches to ON position.
4-98
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