Chapter 2 — Instrument Overview 2-11 Test Panel Connectors
MS272xB + MS8911B UG PN: 10580-00175 Rev. N 2-17
USB Interface – Type Mini-B
The USB 2.0 interface can be used to connect the MS272xB Spectrum Master directly to a PC.
The first time the MS272xB is connected to a PC, the normal USB device detection is
performed by the computer operating system. The CD-ROM that shipped with the instrument
contains a driver for Windows XP that is installed when Master Software Tools is installed.
Drivers are not available for earlier versions of the Windows operating system. During the
driver installation process, place the CD-ROM in the computer drive and specify that the
installation wizard should search the CD-ROM for the driver.
USB Interface – Type A
The MS272xB Spectrum Master can also be a USB Host and allow various USB Flash
Memory devices to be connected to the instrument for storing measurements, setups, and
files.
Headset Jack
The headset jack provides audio output from the built-in AM/FM/SSB demodulator for testing
and troubleshooting wireless communication systems. The jack accepts a 2.5 mm 3-wire
miniature phone plug such as those commonly used with cellular telephones.
Ext Trigger In
A TTL signal that is applied to the External Trigger female BNC input connector causes a
single sweep to occur. In the Spectrum Analyzer mode, it is used in zero span, and triggering
occurs on the rising edge of the signal. After the sweep is complete, the resultant trace is
displayed until the next trigger signal arrives.
To prevent damage to your instrument, do not use pliers or a wrench to tighten the BNC
connector. Do not overtighten the connector.
Ext Ref In
The External Reference In port is a BNC female connector that provides for input of an
external frequency reference. Press the Ext Ref Freq submenu key (in the System menu) to
select the frequency of the external reference from the list that is presented. Valid
frequencies are 1 MHZ, 1.2288 MHz, 1.544 MHz, 2.048 MHz, 2.4576 MHz, 4.8 MHz,
4.9152 MHz, 5 MHz, 9.8304 MHz, 10 MHz, 13 MHz and 19.6608 MHz at amplitude from
–10dBm to +10dBm.
To prevent damage to your instrument, do not use pliers or a wrench to tighten the BNC
connector. Do not overtighten the connector.
Note
For proper detection, Master Software Tools should be installed on the PC prior to
connecting the Spectrum Master to the USB port.
To Next Page
