Operator`s manual

Viewing Waveforms, Vectors, and Pictures
7-22
When you recall an image, you get what was last stored at that location or nothing (if no settings were
ever stored).
Use the IMAGE DENSITY control in the MEMORIES menu to change the brightness of the image.
You must do this before storing it. After the image is stored and recalled, the brightness cannot be
changed.
Locking and Clamping the Signal
The following sections describe how to lock and clamp a signal.
Locking the Signal
The MM-410/AVM-510A lets you lock the signal in two ways:
•
Narrow  used for normal high-quality signals.
•
Wide  used for VCR outputs and other unstable signals.
You can also lock the signal to external sync form a sync source or another signal.
Some signal sources have inherently poor stability, such as the video from consumer-grade VCRs. The
MM-410/AVM-510A lets you lock to these unstable signals by switching from narrow locking to
wide.
If you find a signal display that jitters back and forth horizontally, use the following procedures to
switch to a wide lock:
1. Press the Config button.
2. Select OTHER and then press the Enter button.
3. Select LOCK and then press the Enter button or turn the knob to change from NARROW to
WIDE.
4. Press Clr Mnu to exit.
The signal can also be locked to an external reference. Pressing the Blue button and then the Field
Sel (Ext Ref) button changes from one reference to the other.
You can also change to the external reference using the menu path of: Config, REFERENCE and then
selecting INT/EXT or using the path of: Config, PICT. REF, and then selecting INT/REF.
Clamping the Signal
The MM-410/AVM-510A also allows two types of clamping: Fast and Slow. Fast clamping removes
low frequency components of a signal, such as a 50 or 60 Hz hum. Slow clamping does not remove
this hum.
NOTE:
The signal display is always clamped to remove dc voltages.