Microphone Amplifier 1 Type: GAI
Marconi Co. (Marconiphone, Marconi's Wireless Telegraph Co. Ltd.), GB (not tubes - see also HMV His Master's Voice)
- Country
- Great Britain (UK)
- Manufacturer / Brand
- Marconi Co. (Marconiphone, Marconi's Wireless Telegraph Co. Ltd.), GB (not tubes - see also HMV His Master's Voice)
- Year
- 1923 ?
- Category
- Audio Amplifier or -mixer
- Radiomuseum.org ID
- 345041
- Number of Tubes
- 5
- Wave bands
- - without
- Power type and voltage
- Powered by external power supply or a main unit. / 6 / DC 300 Volt
- Loudspeaker
- - For headphones or amp.
- Material
- Wooden case
- from Radiomuseum.org
- Model: Microphone Amplifier 1 Type: GAI - Marconi Co. Marconiphone,
- Shape
- Tablemodel, with any shape - general.
- Dimensions (WHD)
- 625 x 405 x 300 mm / 24.6 x 15.9 x 11.8 inch
- Notes
-
Marconi Type GA1 single-channel, five-valve microphone amplifier, having resistance-capacitance interstage coupling with metal screening boxes over the valves.
To reduce microphonic noises each valve was connected by gold plate contacts mounted on a sub-assembly and suspended by rubber bands, with flexible leads to the main circuits.
The amplifier had provision for adjusting the high-frequency response to suit the acoustic properties of the hall the microphone was used in.
This was the standard BBC microphone amplifier for several years.
It operated from a 6 V filament supply and a 300 V HT supply.
- Net weight (2.2 lb = 1 kg)
- 45.7 kg / 100 lb 10.6 oz (100.661 lb)
- Mentioned in
- -- Original prospect or advert (Microphone Engineering Handbook ISBN 0 7506 1199 5, Page 279)
- Author
- Model page created by Musée des Radios Museum. See "Data change" for further contributors.
- Other Models
-
Here you find 502 models, 335 with images and 317 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Marconi Co. (Marconiphone, Marconi's Wireless Telegraph Co. Ltd.), GB (not tubes - see also HMV His Master's Voice)
Collections
The model Microphone Amplifier 1 is part of the collections of the following members.