LG-17 Ionospheric Recorder

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PURPOSE:

This transmitter sweeps all or part of the HF frequency range by transmitting short pulses. These pulses are reflected at various layers of the ionosphere, at heights of 100-400 km, and their echoes are received by the receiver and analyzed by the control system. The result is displayed in the form of an ionogram, a graph of reflection height (actually time between transmission and reception of pulse) versus carrier frequency. An ionosonde is used for finding the optimum operation frequencies for broadcasts or two-way communications in the high frequency range. The
results are recorded on photographic film.

SPECIFICATIONS:

Frequency sweep range: 100 KHz to 19.4 MHz
Power output: between 5 and 15 KW
Sweep duration:  4, 8, 16, 21, 40, 80, 160 or 320 seconds per sweep
Pulse repetition frequency: 10, 20, 30 or 60 pulses per second
Pulse duration: 50 or 100 microseconds
Height range: 500 and 1200 km adjustable.
Display: 'B' type for 35mm film; panoramic for 16mm film.
Power consumption:    115 VAC  2.8 kw
Circa: 1948
 

LG-17 Ionospheric Recorder (Photo courtesy Canada Science and Technology Museum, Ottawa)

 
Contributors and Credits

1) Photo  https://ingeniumcanada.org/ingenium/collection-research/collection-item.php?id=1972.0351.001
2) Specs  https://books.google.ca/books?id=L8U3BQAAQBAJ&pg=PR17&lpg=PR17&dq=LG17+ionospheric+recorder&
source=bl&ots=thNIgdB5hj&sig=puw_SLcD3gtZKAXjOOpA9en7IwY&hl=en&sa=X&ved=0ahUKEwjwwsjh5LfZAhX
J6YMKHbioD1oQ6AEIMTAD#v=onepage&q=LG17%20ionospheric%20recorder&f=false
 

Feb 21/18