Nuffield Radio Astronomy Laboratories, Jodrell Bank

7m Telescope

The 7m Telescope is provided at the Nuffield Radio Astronomy Laboratories for the use of students at the University of Manchester as part of their degree programmes.

Telescope Description

The 7m Telescope (or 21ft Telescope as it was originally known) is an alt-azimuth instrument originally built in 1970 by the Marconi company and used for radar tracking of rockets at Woomera, South Australia.

After re-erection at Jodrell Bank, the telescope was equipped with Baldwin Electronic Industry (BEI) 16-bit absolute encoders in both azimuth and elevation, together with in-house drive electronics and extra limit switches for enhanced robust operation.

It can be controlled in both azimuth and elevation by a Marconi servo system currently housed in the telescope control cabin, adjacent to the instrument, and is under full computer control (a MicroVAX II). The servo loop time is approximately 250 milliseconds.

The surface is a 6.4m diameter solid paraboloid, with a prime-focus waveguide feed. The telescope can achieve full sky coverage, and maximum drive speeds are 20 degrees per minute in both axes.

Today, the telescope is used for under-graduate training at the University of Manchester. Experiments conducted by students include:

Introduction to radiotelescopes,
Galactic H-line astronomy, and
Extragalactic H-line astronomy.

Telescope schematic

Click on the image to download the encapsulated PostScript version (8kbytes).

Telescope parameters

              Diameter :  6.4 metres
             Beamwidth :  2 degrees (approx)
                  Tsys :  100 kelvin (approx)
   Aperture efficiency :  55% (approx)
          Polarisation :  Single, linear
   Operating frequency :  1420 MHz (L-band)

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