Tektronix 1705A End of Adjustment Procedure

Checks and Adjustments
1705A Spectrum Monitor 5-27
e. ADJUST --R239 (IF AGC) for maximum signalamplitude.
f. ADJUST --R240 (RF AGC) so the signal is one major Division (±0.5
major Divisions) down from the top graticuleline.
g. ADJUST -- R232 to its midpoint.
18. Adjust 2 dB/Div Position
a. Disconnect thesignal from the L--BAND INPUT.
b. TurnVERTICAL POSITION fully clockwise.
c. Hold the VIDEO push button down until 2 dB/Div appearson the crt
readout.
d. ADJUST-- R140 to position the noise floor to centerscreen.
e. Hold the VIDEO push button down againto exit the 2 dB/Div mode.
19. Adjust 590 MHz Notch
a. Select L--BAND INPUT and set the SPAN/DIV to 10 MHz.
b. Connect the signal generator to th e L--BANDINPUT.
c. Set the signal generatorFrequency to 1200 MHz, and Amplitude to
--20 dBm.
d. Use the HORIZONTALPOSITION control to place the 1200 MHz
signal at the extremeleft graticule mark. A small spur should be visible
near the extremeright graticule mark. Note: R240, RF AGC, may be
adjusted to easevisibility of the spur. Be sure to reset R240 (step 17
part f.).
e. ADJUST --C69 carefully until spur is minimized. Note: While
adjusting C69, note the 1200 MHz amplitude. Thespur should be
minimized without reducingthe 1200 MHz spike by more than 2 dB.
End of Adjustment Procedure