TB 9-6625-2134-24
(211) Press 2 dB/DIV VERTICAL DISPLAY pushbutton to on and switch
variable attenuator through 1 dB steps. If display on crt does not indicate 1.0 minor
division for each 1 dB step, repeat technique of (193) through (209) above.
(212) Adjust signal generator for a full-screen display on crt.
(213) Switch variable attenuator down range and measure the worst case error
over the dynamic range. If TI is in 10 dB/DIV VERTICAL DISPLAY mode, maximum
error must not exceed 1.5 dB over the first 80 dB range; or, if TI is in the 2 dB/DIV
VERTICAL DISPLAY mode, maximum error must not exceed 1.0 dB over the 16 dB range.
(214) Press VERTICAL DISPLAY 2 dB/DIV pushbutton to on.
(215) If display is longer than five divisions from top of crt, adjust R4020 (fig. 16)
for less gain and rebalance Level R4071 (fig. 16) as in (202) above.
(216) Set variable attenuator to 10 dB and adjust signal generator for a full-screen
display on crt (+10 dBm).
(217) Press MIN NOISE pushbutton to on and set variable attenuator for 0 dBm.
(218) Display will return to reference in (216) above.
(219) Adjust REFERENCE LEVEL control to -15 dBm and adjust signal
generator output for a full-screen display on crt.
(220) Press LIN VERTICAL DISPLAY pushbutton to on.
(221) Adjust R4052 (fig. 16) for a full-screen display on crt.
(222) Press VERTICAL DISPLAY 2 dB/DIV and 10 dB/DIV pushbuttons. Crt
display will now be in the same position.
(223) Press LIN VERTICAL DISPLAY pushbutton to on.
(224) Check linearity by adding in sequence 6, 12, and 18 dB of attenuation from
variable attenuator. Display will indicate a reading down from top of display of 4, 6, and 7
(.4) divisions.
(225) Push POWER switch to off. Remove VR modules (fig. 17) and reinstall, using
service kit extender board.
(226) Disconnect signal generator from TI and remove extender board from LOG
and VIDEO board (fig. 16). Reinstall LOG and VIDEO board and reconnect J621 (fig. 16).
(227) Remove VR modules #1 and #2 (fig. 17) and reinstall in TI, using service kit
Pull
POWER switch on and connect CAL OUT to RF INPUT.
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