Tektronix 1705A
Spectrum Monitor, Refurbished

• Full 850 MHz Span for International Satellites
• L-Band and 70 MHz IF Inputs
• Designed for Satellite News Gathering
• Easy, Reliable Operation
• Cost-effective
• On-screen Ku- or C-band Frequency Readout
• On-screen Setup Menu
• Selectable 2 dB/div or 10 dB/div Sensitivity
• Resolution Bandwidth Switchable to 10 kHz
  or 300 kHz
• Span Range and Video Filter Selection
• Bright, Clear Display

Dual Band Operation

Separate signal inputs allow connection to the two primary signals of interest in a television uplink/downlink system. A 45-100 MHz band allows observation of the television exciter at the 70 MHz IF monitoring point for a check of video deviation and aural sub carrier injection. A 950-1800 MHz band, with a separate RF input, allows observation of the full satellite downlink spectrum as down converted by the antenna-mounted, low-noise block down converter (not supplied). The input levels available in typical satellite television systems match the input sensitivity of the 1705A without need for operator adjustable input attenuators.

In addition to a span of the full spectrum in each band, the 1705A allows a selection of narrow spans and resolution filters for observation of individual satellite transponders, the video FM modulation envelope, or associated audio carriers.

Using the 1705A, the operator can quickly identify the assigned satellite and transponder and correctly adjust the direction and polarization of the portable uplink/downlink antenna. Precise antenna pointing is facilitated by a selectable 2 dB or 10 dB per major division vertical screen sensitivity with vertical position control.

Compact Size

The 1705A is unique in size, shape and utility. 8.5 in. (215.9 mm) wide and 5.25 in. (133.4 mm) high, it fits into a standard Tektronix dual half-rack WFM7F05 Option OO cabinet, along with a matching 1700 Series waveform, vector or combination monitor.

Microprocessor Control

A menu selected readout offset allows on-screen indication of the Ku-band or C-band satellite operating frequency in steps of 10 MHz. The offset may be set for local oscillators operating above or below the received signal. The status of all front panel buttons is stored when power is removed and all modes are restored on power-up, ready for quick operation. Function indicators are lighted for visibility in television operating environments.

RF Spectrum Display

Span per division, resolution bandwidth and display video bandwidth may be selected for full satellite, transponder or discrete carrier display. The band of interest is highlighted in the full span mode, with frequency indicated as an alphanumeric readout. In 10 MHz, 1 MHz and 100 kHz span/div modes, the readout indicates the frequency of the spectrum displayed directly under the cursor.

A CENTER FREQUENCY control marks the display in full span and moves the spectral view through the entire selected band in narrower spans.

1705A Rear Panel.

Bright, Full Size CRT Display

The signal is displayed on a bright, mesh type CRT with internal graticule to eliminate parallax. Variable graticule illumination improves readability under difficult conditions. The display is a full 8x10 cm and the bezel accepts camera and viewing hood options designed for Tektronix 1700 Series monitors.

Designed for Rugged Use

The 1705A spectrum monitor is designed to provide reliable operation in portable news gathering applications. The 1705A is built to withstand extremes of temperature, altitude and vibration. Its small size provides a freedom of system design critical in the rapidly changing television news environment.