User's Manual

TB8100 Calibration Kit User’s Manual Adjusting the Exciter Lock Band 13
Adjusting the Exciter Lock Band
If you are preparing the base station for operation, adjusting the exciter lock
band is the third step in tuning the reciter. Alternatively, this procedure can be
performed independently of the other two calibration wizards on the
Frequency Setup tab. Adjusting the exciter lock band defines the range of
frequencies that the base station is able to transmit on. For K-band UHF
exciters, the procedure is somewhat different: you select one of the two lock
bands instead of defining a center frequency.
Note: When performing this procedure, you don’t need to
terminate the exciter output port. An internal output pad means that
there is a good impedance match at this interface.
Equipment ■ Tuning tool
■ CTU
To calibrate the exciter lock band
1. Ensure you are already connected to the reciter (see “Connecting to a
Reciter Outside the Subrack” on page 5).
2. Select the Frequency Setup tab, and double-click Set Exciter VCO. The
Set Exciter VCO Wizard appears.
3. Enter the center frequency (which must be a multiple of 500 kHz) of the
lock band that you want to use, and click Next.
Alternatively, for a K-band UHF exciter, select one of the two available lock
bands. This specifies the lock band that you adjust and that the exciter oper-
ates in.
4. Insert the tuning tool into the correct exciter VCO tuning hole (see below)
and adjust the trimmer until the actual band matches the desired band. The
bands turn green. (For K-band UHF exciters, adjustment should only be
necessary if the board has been repaired.) Click Finish.
Once you have finished adjusting the exciter lock band, the icon on the
Frequency Setup tab indicates that this task is complete.
Exciter VCO tuning hole
for H-band
Exciter VCO tunin
g
hole for VHF
Exciter VCO tuning
hole for K-band
(850-870 MHz) and
L-band (852-854 MHz)
Exciter VCO tuning
hole for K-band
(762-776 MHz) and
L-band (928-941 MHz)