EUROTEL - ITALY
ETL0480TBD
IV - ALIGNMENT & MAINTENANCE INSTRUCTIONS
1 ) ETL0470 - Changing the channel of operation, simplified procedure
To change the channel of operation, two procedures must be followed.
•
The output filter (if installed) must be re-aligned on the new frequency. A detailed procedure is
available in section D, technical information.
•
The calibration of the internal power sampling directional couplers must be changed, as outlined
below.
When changing the channel of operation of the ETL0470, it is necessary to change the calibration of
the internal power sampling directional couplers. Calibration data is stored in 100 MHz intervals in the
memory of the resident Microprocessor and is changed by following this step by step procedure.
IMPORTANT: The menu entries from V.unreg, as described below, are only available on Equipment with Serial
Number: 9314 or higher. For older equipment, please contact the factory.
⇒
⇒
⇒
⇒
⇒
⇒
⇒
⇒
Set upper and lower positions of the front panel meter to
Vunreg.
Push “
SELECT
” several times, until “
Frequency band
” appears.
Push “
Enter
”, to enter this menu. You will see the frequency band at which the Amplifier had
previously been set up.
On the “+” and “-“ push-buttons, the entire UHF band is available, in steps of 100 MHz.
Now using “+” or “-“ set the frequency nearest to the new operating channel which must be
used.
EXAMPLE
: suppose original channel is 28 B/G (Vision frequency 527.25 MHz) and the new
channel is 58 B/G (Vision frequency 767.25). You would find the original step as : 550-650
[MHz]. Now push “+” until you see:
750-800
[MHz].
Now push: “Set”, to store the new setting. The word “
Stored
” will appear on the display.
After a few seconds the system will automatically revert to normal operating status.
WARNING: If the Amplifier is operated at a different channel without executing this calibration procedure, all the
internal RF power readings will be out of calibration and therefore the front panel wattmeter readings, the alarm
thresholds and the protection thresholds will be out of calibration.
October 2002
CMAN0480ENG
Page 31
