Multiple Tuner -Long

Frequency range: 80 metres to 2600 metres in four bands per the "Handbook of Technical Instruction for Wireless Telegraphists"

Band 1 - 80 to 160 metres
Band 2 - 150 to 1600 metres
Band 3- 1600 to 2000 metres
Band 4 - 2000 to 2600 metres.

Frequency range derived from a Marconi UK radio catalogue:  100 to 2500 metres:

Made by : Marconi UK

The multiple tuner was designed to tune the Magnetic Detector (aka Maggie) . The pick up coil on the Magnetic Detector had a fixed frequency and a low impedance for a telephone receiver (160 ohms). The input on the Multiple tuner was low to match it

/multiple_tuner_01.jpg
External view of the multiple tuner. (Sparkmuseum.com  photo)
multiple_tuner_01c.jpg
Iinternal view of the multiple tuner - long . The tuner is dominated by three large coils. The smaller coil  at the lower left was used to  prevent static buildup on the antenna by slowly draining the charge.  (Sparkmuseum.com  photo) 
/multiple_tuner_2a.jpg
Diagram showing the major parts of the multiple tuner. Download to enlarge
multiple_tuner_02c.jpg
Multiple tuner schematic, 
multiple_tuner_03.jpg
Interconnection scheme between the multiple tuner and the Maggie Detector. Download image to enlarge. 
Unless otherwise noted all images in this table are courtesy Handbook of Technical Instruction for Wireless Telegraphists). 

 
/multiple_tuner_band_arrangement.jpg
Band arranement for the Multiple Tuner. (Courtesy Handbook of Technical Instruction for Wireless Telegraphists). 

Contributors and Credits:

1) Lewis Bodkin  <05bodkin555(at)gmail.com>

Back to Equipment
June 11/18