6 Input/Output
6.2 Input
The current Mixer selection (the current or most recently connected USB Mixer, or
the most recent Mixer Preset, or Custom if you have modified the setup) reads out at
the top of this screen as Mixer Selection
The Harmonic Table currently being used reads out below the Mixer Selection. It
shows each range being used for the current mixer. Note that a band may be made
up of up to 3 ranges. Each range represents a choice of mixer harmonic and doubler
state. When you select a Mixer Preset, it sets the instrument Start and Stop
frequency to the values shown in the Harmonic Table; Start Freq is set to the Min
Freq for the bottom range, and Stop Freq is set to the Max Freq for the top range. In
many cases you can exceed these nominal values; the absolute maximum and
minimum frequency for each preset are shown in the tables that accompany the
control descriptions for the Mixer Presets.
NOTE
If the current measurement has a limited Span available to it and cannot achieve
the Span shown in the table (Span = Stop Freq – Start Freq), the instrument uses
the maximum Span the measurement allows, and sets Center Frequency to the
midpoint of the Start and Stop Freq values in the Harmonic Table.
You may edit some of the Harmonic and LO Doubler fields in the Harmonic Table, as
shown by the gray backgrounds of these fields. When you edit the Harmonic Table,
the Mixer Selection changes to Custom. To change it back you must go back into the
Mixer Presets menu and select a Preset.
When you edit the Harmonic Table, the nominal Min Freq and Max Freq that are
available will usually be different than the Preset you were using; and the absolute
frequency limits will change as well. This may result in a change to your Start and/or
Stop Freq, if the current values fall outside the new range, requiring you to retune
your Center Freq to get your signal back in the center.
The instrument supports the Keysight M1970 Series Harmonic Mixers with USB
connection. While in External Mixing, if one of these mixers is plugged in to a USB
port, it is automatically detected and displayed in the “USB Mixer” area of the setup
screen, including its model number and serial number.
The instrument assumes that if you plug a mixer into the USB you want to use that
mixer, so:
1.
If a USB mixer is connected to the USB port, the Mixer Presets button is grayed-
out, as none of the presets make sense with a USB Mixer connected. Note that
once the instrument has acquired the USB Mixer, the mixer selection will remain
if it is subsequently unplugged from the USB, allowing you to plug it back in with
no change to your settings. However, once you unplug it, the Mixer Presets
control ceases to be grayed-out, allowing you to preset to a different mixer
2.
When Restore Input/Output Defaults is performed, if a Keysight USB Mixer is
plugged into the instrument’s USB port, the Mixer Selection remains unchanged
2055 Short Range Comms & IoT Mode User's &Programmer's Reference
To Next Page
Loading...
Need help?
General
