Black ground lead W4605 to test set GROUND jack and to a good ground on the computer drawer.
Set BRIDGE ADJ dial to 0000.
Set SINGLE BEAM-DUAL BEAM switch S857 to SINGLE BEAM.
Set LOWER BEAM ELEVATION counter M821 to +7 mils.
Adjust potentiometer R881 for a null on test set.
(10) Disconnect test probe and red test lead.
(11) Set LOWER BEAM ELEVATION counter M821 to +21 mils.
(12) TEST NORMAL switch to NORMAL.
(13) Adjust potentiometer R884 for reading of 1. 00 on the calibrated C gears.
(14) Perform computer accuracy checks (single beam operation).
5-10. COMPUTER ACCURACY CHECK (SINGLE-BEAM OPERATION)
It is assumed that the requirements of the normal (dual-beam operation) check of computer accuracy given in
paragraph 44, TM 11-5840-208-20 have been met prior to this modification procedure. The accuracy of the computer
during single-beam operation is checked by performing the series of problems listed in the chart in e below. The accuracy
of the computer is not acceptable when the computed solution of any problem contains an error of more than 40 meters
for weapon easting (EW) or northing (NW), or more than 70 meters for combined easting and northing, or more than .15 for
"C". Preliminary instructions are included below.
On the computer, set RADAR LOCATION EASTING and NORTHING counters to 000000 METERS.
Set SINGLE BEAM-DUAL BEAM switch to SINGLE BEAM.
Set weapon HEIGHT and RADAR HEIGHT counters to 1000 METERS.
With the detent switch in the OFF position, set ∆ RANGE and ∆ AZIMUTH handwheels in detent.
For each problem in the chart given below, with the TEST-NORMAL switch on the right side of the computer at
TEST, set ∆ T, HW, RL, AZ, EL, ∆ R and ∆ A as given in the chart. Then set the TEST-NORMAL switch to NORMAL and
read weapon range (RW), weapon azimuth (AW), weapon easting (EW), weapon northing (NW) and "C" solutions on the
computer, and compare these solutions with those in the chart.
Note: When setting AZ into the computer, first use the AZ ORIENT switch, followed by a fine setting, using the
LOWER BEAM AZIMUTH control. Just prior to setting ∆ R and ∆ A into the computer, set the detent switch to the
DETENT RELEASE position.