To quit this function, the MENU key must be pressed.
Channel
Using the set of channel tables included in the MO-180 makes the output
frequency tuning faster. This allows direct selection of standard frequencies used in
most countries.
Entering this function, a list of all available channels is displayed sequentially.
Turning the encoder will lead us to the desired one. Pushing the encoder selection key
will exit that function.
The channel list is taken from a set of channel plans loaded into the equipment.
The available channel plans are displayed and selected from the CONFIGURATION
menu, as we'll see later.
Also in this case, frequency changes are applied immediately to the RF stage,
allowing an interactive frequency adjustment.
The list of channel plans can be found in Appendix A.
Disable
This option is to disable the RF output. This is performed by introducing a strong
attenuation (around 80 dB) to the RF signal. At the same time, the IF frequency is
tuned to a nominal value of 36 MHz. The possible values are NO to enable the RF
output and YES to disable it.
4.9 LEVEL functions
This menu entry groups the functions related to RF level adjustment. The
MO-180 has a built-in programmable attenuator of 60 dB, in 1 dB steps. At the same
time, the nominal RF level can be finely adjusted using a voltage controlled attenuator.
This allows to set a reference level using the voltage controlled attenuator, to then
apply the mentioned 1 dB attenuation steps to that reference value.
Also included here are the controls for the Crest Factor Reduction algorithm and
the Non-Linear Pre-Distorter.
The RF gain structure can be controlled using the following functions.
Attenuation
This function allows to select the RF output level by applying 1 dB attenuation
steps, from 0 dB to 60 dB. Turning the encoder clockwise increases the attenuation,
reducing the output level. Turning counter-clockwise enables the opposite behaviour.
Page 28
USER'S MANUAL MO-180
04/2008