Telequipment Serviscope Minor

Telequipment Serviscope Minor single channel oscilloscope designed for educational purposes. Mains operated. 210, 230, 250volts AC 50Hz. Display 50mm X 50mm. It uses three Brimar 6BW7 valves, one Mullard ECC81 one Mullard EB91 and one EZ80 full wave rectifier.


 The 2" diameter cathode ray tube operates at 600volts overall, giving a bright trace over the whole of the working area (5 x 5 cms). A green filter improves the contrast under conditions of high ambient light. The Y amplifier is DC coupled to the Y deflection plates and has a sensitivity greater than l00 mV/division and a frequency response from DC to 30 kHz (-3db).
The input gain control varies the signal level from 100mV/div. to 50 volts/div. The input impedance is 1megohm shunted by approximately 30 pF.

The X axis sweep generator is a triggered Miller run down circuit providing good linearity. Three preset sweep speeds are provided, ranges l, 2 and 3. These are approximately l00 mS/div., I0 mS/div. and 1 mS/div. A variable control provides continuous overlap between the ranges, giving a total range of sweep speeds from 100 mS/div. to 100uS/div.

The trace blanking waveform from the sweep generator is AC coupled and DC restored, so giving uniform brightness toon all sweep speeds. The oscilloscope triggers internally, automatically. No adjustment is provided. In the absence of a signal the sweep free runs at about I0 c/s.

Interior top note the dates on capacitors

Interior left hand side

Interior right hand side the red wire is now connected to 230V tag

This is one of several items which I have been given by Glyn Jones. It was in working order but I felt that the display could have been brighter. On opening it up I found that the mains lead was connected to the 250V tapping as can be seen in the picture above, when connected to the 230V one the display seemed fine. Dates on the electrolytic capacitors indicate that it would have been manufactured in early 1974. This model was first introduced in 1965 and made by Telequipment Ltd., 313 Chase Road, Southgate, London N.14.

TELEQUIPMENT is a registered trademark of Tektronix U.K. Limited of 313 Chase Road, Southgate, London, N14 6JJ. The SERVISCOPE trade mark dates from April 1958

If you are looking at this page you might find this Tektronix booklet of interest troubleshooting-scopes.pdf