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Tektronix 1705A
Spectrum Monitor
Tektronix 1705A

Produced from 1988 to 2000+

(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix 1705A is a spectrum monitor designed primarily for locating Ku or C-Band satellites and monitoring their signals.

It operates by using LNB down converters to the L-Band (950 MHz to 1.8 GHz), and monitoring up link transmissions utilizing an upconverter to the 70 MHz IF (45 MHz to 100 MHz). The resolution bandwidths 10 kHz and 300 kHz provides measurement resolution proportional to the frequency accuracy or span.

The CRT graticule can be lit by setting an internal jumper. The front-panel switch settings can be saved to NVRAM. The user interface has on-screen frequency readout as well as setup menus. The L-Band readout may be reconfigured to display a satellite frequency in the range of 0.9 GHz to 20 GHz.

Key Specifications

Frequency L-Band: 950 MHz to 1.8 GHz; 70 MHz band: 45 MHz to 100 MHz
Frequency Span L-Band: Full, 10 MHz/div, 1 MHz/div, and 10 kHz/div; 70 MHz: Full, 1 MHz/div, and 100 kHz/div
Resolution Bandwidth –6 dB bandwidth selections 300 kHz / 10 kHz
RF Input 75 Ω
Maximum Safe Input Power L-Band: –30 dBm; 70 MHz: –20 dBm
Minimum Signal Input –80 dBm
Video Filter Reduces Video Bandwidth to ≈ 10 kHz
RF Attenuator Range No built-in internal attenuation. Apply an external attenuator to keep the maximum safe input power below the rating listed above
Sweep Speed 20 ms to 200 ms, variable
Display 80 mm × 100 mm (3" × 4") CRT, P31 (Opt. 74: White Phosphor)
Weight Standard accessories: 3.8 kg (8.5 lbs)
Power 90 − 250 VAC, 48 to 66 Hz, 35 W

Rear panel:

  • L-BAND INPUT, F connector: 900 – 2000 MHz down-converted from L-Band RF by a low-noise block converter (LNB)
  • LNB POWER switch enables or disables an 18 V supply for the LNB at the L-band input
  • 70 MHz INPUT BNC connector (for 45 MHz – 100 MHz RF)