HP 8642A Operating Manual page 194

Operation
Model 8642A/B
Special Functions (cont'd)
DETAILED DESCRIPTIONS OF ALL SPECIAL FUNCTIONS (cont'd)
121. Sweep Up and Down On. Sweep Up and Down is a type of sweep that causes the Signal Generator
to sweep from the start end-point to the stop end-point and then from the stop end-point to the start
end-point in the same amount of time (during auto or single sweep modes). See Figure 3-7, Sweep
Waveforms, in RF Frequency Sweep, page 3-66, or Figure 3-10, Sweep Waveforms, in Amplitude Sweep,
page 3-93.
122. Linear Amplitude Sweep. This special function selects a linearly stepped output rather than the
usual logarithmicly stepped output. Use a sweep time greater than 900 ms to obtain maximum sweep
resolution.
123. Phase Continuous Frequency Sweep. Phase Continuous Frequency Sweep enables the Signal
Generator to frequency sweep between two end-points in a linear, phase continuous manner. Refer to RF
Frequency Sweep, page 3-49.
134. Turn Off LCD Lighting. This special function turns off the LCD back-lighting in the display.
135. Disable Display. Special Function 1 35 causes the Signal Generator to execute commands without
displaying the instrument state (useful in secure environments).
204. Disable ALC Off. This special function re-enables the output leveling loop that was disabled with
Special Function 4.
205. External Low Rate FM Off
This special function turns off the FM modulation source selected with Special Function 5. When Special
Function 5 is turned off in this way, the Signal Generator selects external, ac-coupled FM.
206. FM Pre-Emphasis Off. This special function turns off the pre-emphasis selected with Special
Function 6.
207. Low Distortion FM/<$M Off. This special function switches out the shaper circuitry inserted with
Special Function 7.
208. Prefer Divide Bands. This special function re-enables the automatic preference of selecting the
divide bands over the heterodyne band if possible. This preference is disabled with Special Function 8.
209. Attenuator Range Hold Off. This special function turns off Attenuator Range Hold selected with
Special Function 9.
211. Special Function Verify On. This special function re-enables the automatic display of the special
function description disabled with Special Function 111.
212. Internal + External Low Rate FM Off. This special function turns off the FM modulation source
selected with Special Function 112. When Special Function 112 is turned off this way, the Signal
Generator selects internal and external, ac-coupled FM summed together.
213. Modulation Frequency Correction On. This special function re-enables the single-band calibration
that normally occurs whenever the modulation oscillator frequency is set or the internal modulation
oscillator is put into use. Refer to page 3-1 7 3, Special Function 1 1 3.
3-174