Millivoltmeter 120
Comark Electronics Ltd.; Littlehampton
- Country
- Great Britain (UK)
- Manufacturer / Brand
- Comark Electronics Ltd.; Littlehampton
- Year
- 1963 ?
- Category
- Service- or Lab Equipment
- Radiomuseum.org ID
- 364840
Wireless World Sep 1963, p. 457.
- Number of Transistors
- Semiconductors present.
- Semiconductors
- Wave bands
- - without
- Power type and voltage
- Dry Batteries
- Loudspeaker
- - - No sound reproduction output.
- Material
- Metal case
- from Radiomuseum.org
- Model: Millivoltmeter 120 - Comark Electronics Ltd.;
- Shape
- Portable set > 8 inch (also usable without mains)
- Notes
-
Millivoltmeter designed for low-level, high-impedance working, the Comark Type 120 d.v. millivoltmeter has a maximum sensitivity of 1 mV full scale and a 1 MΩ/V input resistance. The instrument, which uses transistors, is of the chopper amplifier type with linearising negative feedback. Transistor noise is of a sufficiently low level to allow an input of 10 µV to be detected. A centre zero facility is provided, and the meter movement is of the taut-wire suspension type. Maximum voltage measurement is 100 V full scale with an accuracy of 2% of f.s.d. at 20°C, zero drift being less than 0.2% per degree Centigrade.
Resistance measurements can be carried out on a linear scale up to a maximum of 10 MΩ at an accuracy better than 5 % of f.s.d.
The instrument is powered by three internal mercury cells.
- Price in first year of sale
- 36.00 GB £
- Mentioned in
- Wireless World (The), London (WW, 79) (Sep 1963, p. 457..)
- Author
- Model page created by Gary Cowans. See "Data change" for further contributors.
- Other Models
-
Here you find 5 models, 5 with images and 2 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Comark Electronics Ltd.; Littlehampton