Dawn CONTROL-1500A Manual page 35

CONTROL-1500A Single Axis Antenna Controller
2. Jog the antenna off of the satellite so the antenna is looking at nothing. Measure and
record the receiver's AGC voltage. In the description that follows, the term 'off satellite' will
be used to refer to this case where the antenna is positioned well off of any satellite,
looking at nothing.
Note that if both AGC inputs will be utilized, record the 'off satellite' voltage for both
receivers.
3. If the difference between the two recorded values is less than 1 volt, connect the receiver's
AGC output to the controller's AGC1 input. Otherwise, connect the receiver's AGC output
to the controller's AGC2 input. Be sure to connect the ground return of the controller to a
ground on the receiver. See figure 3.1.
If both AGC channels will be utilized, connect the Signal Strength output of the receiver
with the smaller 'on satellite' – 'off satellite' voltage difference to the controller's AGC1
input. Connect the other receiver's Signal Strength output to the controller's AGC2 input.
4. If the AGC voltage associated with the 'on satellite' case is greater than that of the 'off
satellite' case, the receiver has POSITIVE AGC polarity (otherwise the receiver has
NEGATIVE AGC polarity). Go to CONFIG mode and use the SCROLL keys to bring up the
AGC Polarity item. Key in the proper polarity using either the 0 or 1 key, and terminate the
entry with the ENTER key.
5a. If two receivers are interfaced to the controller proceed to step 6.
If the receiver's AGC has NEGATIVE polarity, go to step 5b. If the receiver's AGC has
POSITIVE polarity, from Manual mode use the Scroll Up/Scroll Down keys to examine the
signal strength for the AGC channel which was NOT selected in step 3. If the signal
strength reading for that channel is greater than 10, adjust the OFFSET and GAIN for that
channel until the signal strength reading for that channel is less than 10. To lower the
displayed signal strength turn the OFFSET pot clockwise and the SCALE pot counter-
clockwise. Proceed to step 6.
For versions of the software (v1.4x and earlier) that do not support use of the Scroll
Up/Down keys to display AGC1 or AGC2, rotate the OFFSET pot clockwise 20 turns or
until a faint click is audible. Similarly, rotate the SCALE pot counterclockwise 20 turns or
until a faint click is audible.
5b. If the receiver's AGC has NEGATIVE polarity and only one receiver is interfaced to the
controller, connect a jumper from the controller's unused AGC input channel to connector
J1, pin 11. From Manual mode use the Scroll Up/Down keys to examine the signal
strength for the AGC channel which was not selected in step 3 above. If the signal strength
reading for that channel is greater than 10, adjust the OFFSET and GAIN pots for that
channel until the signal strength reading for that channel is less than 10. To lower the
displayed signal strength value, turn the OFFSET pot counter-clockwise and the SCALE
pot clockwise. When this is accomplished proceed to step 6.
For versions of the software (v1.4x and earlier) that do not support use of the Scroll
Up/Down keys to display AGC1 or AGC2, rotate the OFFSET pot counterclockwise 20
DAWNco • 3340 S. Lapeer Rd • Orion, MI 48359-1320 • Ph (248) 391-9200 • Fax (248) 391-9207 • sales@DAWNco.com
Chapter 3 Installation/Setup 28