Research Concepts RC2000A - Manual (Page 100)

100 RC2000A Dual Axis Antenna Controller Appendix I 2.6x Addendum
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.
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.
6. In the next few steps of the procedure, the OFFSET and GAIN pots of the AGC channel(s)
connected to the receiver's AGC output are adjusted so that the 'off satellite' signal strength value is
between 50 and 100 and the 'on satellite' signal strength value is between 600 and 700. The
adjustments are made from MANUAL mode.
If both controller AGC ports are used, steps 7 through 9 should be performed for each channel.
Use the Scroll Up/Down keys to view the AGC channel whose pots are being adjusted.
Note that the GAIN and OFFSET adjustments are implemented using 20 turn pots. A lot of turns
may be required.
7. Go to MANUAL mode, position the antenna 'off satellite' (if it is not already there), Adjust the
OFFSET pot (for POSITIVE polarity receivers) or the GAIN pot (for NEGATIVE polarity receivers)
so that the signal strength reading is about 75.
If the AGC has POSITIVE polarity and the signal strength is too low, turn the OFFSET pot counter-
clockwise. If the AGC has POSITIVE polarity and the signal strength is too high, turn the OFFSET
pot clockwise.
If the AGC has NEGATIVE polarity and the signal strength is too low, turn the GAIN pot counter-
clockwise. If the AGC has NEGATIVE polarity and the signal strength is too high, turn the GAIN pot
clockwise.
8. While still in MANUAL mode, position the antenna 'on satellite' and adjust the GAIN pot (for
POSITIVE polarity receivers) or the OFFSET pot (for NEGATIVE polarity receivers) so that the
signal strength value is about 650.
If the AGC has POSITIVE polarity and the signal strength is too low, adjust the GAIN pot clockwise.
If the AGC has POSITIVE polarity and the signal strength value is too high, adjust the GAIN pot
counter-clockwise.
If the AGC has NEGATIVE polarity and the signal strength is too low, adjust the OFFSET pot
clockwise. If the AGC has NEGATIVE polarity and the signal strength value is too high, adjust the
OFFSET pot counter-clockwise.
9. Position the antenna 'off satellite'. If the signal strength is between 50 and 100, proceed to step 11.
If the signal strength is less than 50 or greater than 100 perform steps 8 and 9 again.
10. Position the antenna 'on satellite'. Jog the antenna off of the satellite until the picture is just barely
watchable. Note the signal strength value. Go to CONFIG mode and use the SCROLL keys to
bring up either the AGC C Band Threshold item or the AGC K Band Threshold item, whichever is
appropriate for the frequency band that the user has chosen to operate at (and has adjusted the
pots at). Key in the signal strength value noted above. Terminate the entry with the ENTER key.
For a dual receiver system, both AGC channels are used. The thing to remember is that the same
Research Concepts, Inc. • 5420 Martindale Road • Shawnee, Kansas • 66218-9680 • USA www.researchconcepts.com