ACT-5X Exciter User Manual
Version 3.0 05/07/2015
Page 21 of 26
4 Connection
4.1 Connect the Transmitter
Don’t turn on or off the exciter/translator when the transmitter is running. The correct order is:
First, turn on the exciter/translator and put it in Exciter Mode. Or if Translator Mode is preferred,
ensure there is valid RF input connected to the translator, or the function of Muting RF output on
loss of missing or invalid input signal is turned off. Otherwise there may be no RF signal output.
Measure the RF output level of the exciter/translator to make sure it meets the requirement of the
transmitter input level. If the output level is out of range, change the parameter "POWER" in
"RF" sub-menu in control mode to make the adjustments. Refer to Table 7, Chapter 3 for details.
If the output signal level is within range, connect the exciter/translator's output (port [RF_OUT]
on back panel) to the transmitter's input.
After the exciter/translator is stable, turn on the transmitter.
Likewise, turn off the transmitter first before making any change to the exciter/translator's
settings. Restart the transmitter after the exciter/translator is stable again.
4.2 Start ADPC function
1)
After the exciter/translator is connected to a transmitter, first of all measure the level of the
transmitter's output
(both
before and after
band-pass filter). Make sure it meets the requirement of
exciter/translator's feedback level (-30 dBm ~ 0 dBm and recommended range is -15 dBm to -5 dBm).
1)
If the signal level is out of range, use extra devices, e.g. attenuator, to make adjustments.
2)
If the signal level is within the range, connect the transmitter's output which is
before the
band-pass filter
to port [RF_IN_B] and another output which is
after
band-pass filter
to port
[RF_IN_A]
respectively. Figure 1 below demonstrates the correct connection.
Start ADPC function
With AGC turned OFF, Select option "UPDATE" under "ADPC" of the “SYSTEM” sub-menu.
Press the OK button to start the correction process, which will in sequence run Linear and
Non-linear correction showing the status ("Wait a moment...") and readings of "TSNR", "LID"
and "UID" on the front panel LCD. Usually this takes about 10 minutes to finish the total
compensation of both
the linear and non-linear
distortion in the whole transmission system
including both power amplifier and band-pass filter. Once the new correction coefficients have
been computed and applied, there is an automatic "Saving" process which stores the ADPC data
into the on-board memory.
Readings of "TSNR", "LID" and "UID" provide a continuous measurement and display of
quality of feedback signal during the ADPC process. Compare these readings before and after the
ADPC process as the reference of correction performance.
There is a "Loading" process that takes roughly 10-15 seconds when the exciter/translator is first
turned on again with the ADPC "HOLD" option selected. This
restores
the ADPC data saved the
last time an entire ADPC process was successfully completed.