Specifications

Operation
58 Runco RS-1100 Series Owner’s Operating Manual
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• Signal Fine Tune: This sub-menu displays current input signal timing information and
provides the following advanced settings.
• Clamp Place: “Clamping” refers to the removal of any DC offset from the analog
input signal so that it can be accurately digitized. Clamping normally occurs a short
time after the trailing edge of the horizontal sync signal (H-sync), when the video
source is known to be producing black. The analog-to-digital converter in the
RS-1100 uses the input signal at this point as its black level reference and
processes all other signal levels accordingly.
Clamp Place is the number of pixel periods (1 to 255 inclusive) that should pass after
the trailing edge of H-sync before clamping starts. If images from an HD source
appear excessively dim, try adjusting the Clamp Place to correct this.
• Clamp Duration: Clamp Duration is the number of pixel periods (1 to 255 inclusive)
for which clamping is active. For best results, set the clamp duration to include the
majority of the black reference signal time that follows the H-sync signal trailing
edge. Increase the Clamp Duration if you see brightness changes at the top of the
screen and/or slow recovery from large changes in the average picture level (APL),
or brightness.
• Pre-Coast/Post-Coast: With some HD sources, H-sync may become distorted or
disappear altogether during the vertical sync (V-sync) pulse period. With composite
sync or sync-on-green RGB signals, H-sync may contain equalization pulses or
other distortions during V-sync.
To maintain proper signal timing, such distortions should be ignored; otherwise,
“tearing” of the image at the top of the display may result. The solution is to employ
“coasting,” which allows the pixel clock to free-run at its then-current frequency. It
can do so for several lines without significant frequency drift.
Pre-Coast sets the number of H-sync periods that Coast becomes active prior to
V-sync. Post-Coast sets the number of H-sync periods that Coast stays active
following V-sync. Increase one or both settings to correct jitter or instability in the
image.
• SOG (Sync-On-Green) Threshold: SOG Threshold adjusts the voltage level of the
RS-1100 Sync-on-Green signal detection circuitry. Adjust the SOG Threshold if an
image from a “sync on green” RGB source is unstable or won’t display at all. Higher
settings lower the SOG detection threshold in 10-millivolt steps; lower settings raise
the threshold. The range is from 0 (330 mV) to 31 (10 mV) inclusive. The default
setting is 23 (100 mV) and should rarely require adjustment.
• Overscan Rate: Refer to Image Over Scan on page 59.
Timing 1080ix60
Clamp Place +80
Clamp Duration +10
Pre-Coast +10
Post Coast +5
SOG Threshold +23
Overscan Rate +2