LG-17 Ionospheric Recorder


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.


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&

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Feb 21/18