Changing The Search Parameters; Auto Thres; El Step Size - Sea Tel 4009-9 BROADBAND-AT-SEA Installation Manual

4009-9 Installation Manual

10.2. Changing the Search Parameters

The information above described what some of these parameters need to be set to for a specific search pattern.
Below are some additional pieces of information on the other parameters and the steps to change any one of
these parameters.

10.2.1. AUTO THRES

Sets offset of AGC tracking threshold above the average noise floor. Units are in A/D counts,
approximately 20 counts/dB. A setting of 0 disables auto threshold, therefore, the operator would have
to manually enter a threshold value.
When AUTO THRESHOLD is enabled (any value between 1-255), the ACU automatically re-sets the AGC
tracking threshold whenever the antenna Targets (AZ, EL or SAT) or Searches. The new AGC threshold is
set to the average signal level input (approximate background noise level) plus the AUTO THRES offset
value. EXAMPLE: If the Noise Floor off satellite is 1000 counts of AGC and Auto Threshold is set to 100,
Threshold will be set to approximately 1100 after the antenna has finished targeting or Searching.
To change the Automatic Threshold value OR manually set threshold; Note the Peak "on satellite" AGC
value, move EL and note the "off satellite" (Noise Floor) AGC value. Calculate the Difference between
Peak AGC and Noise Floor AGC. AUTO THRES should be set to 1/3 (to ½) of the Difference. This will
usually be around 100 counts (3 dB) for a typical antenna configuration. Changes to this parameter may
be required based on carrier tracking frequency, possible adjacent satellite, or ambient interference with
desired satellite.
To manually update, press the LEFT arrow key to bring the cursor up under the least significant
character. Continue to move the cursor until the desired character to be edited is underscored (selected).
Use the UP or DOWN arrow keys to increment or decrement the selected character.
Use the LEFT or RIGHT arrow key to move the cursor left or right to select other characters to modify.
When you are finished modifying press ENTER to execute the new value OR press NEXT to abort and exit
setup mode.

10.2.2. EL STEP SIZE

For proper DishScan® operation this parameter must be set to factory default value of 0000.
To manually update, press the LEFT arrow key to bring the cursor up under the least significant
character. Continue to move the cursor until the desired character to be edited is underscored (selected).
Use the UP or DOWN arrow keys to increment or decrement the selected character.
10-4
Setup – Searching