In this situation, each time we press the encoder button, the frequency step will be
modified to 1 MHz, 100 kHz, 10 kHz, 1 kHz, 100 Hz, 10 Hz, 1 Hz and again to 10 MHz,
allowing a cyclic selection of the desired step value.
To quit this function, the MENU key must be pressed.
Channel: Using the set of channel tables included in the MO-160 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. At the same time, the IF
frequency is tuned to a nominal value of 36 MHz. The selectable values are:
NO.
YES.
4.6 LEVEL functions
This menu item collects the functions related to RF level adjustment. The MO-160
has a built-in variable attenuator of 25 to 30 dB, programmed in 33 steps of 1 dB
aproximately. 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 approximately
to that reference value.
That 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 approximately, from 0 dB to 30 dB. Turning the encoder
CW increases the attenuation, reducing the output level. Turning CCW
enables the opposite behaviour.
Page 18
USER'S MANUAL. MO-160
02/2008