A 150-Kc Carrier System for Radio Relay Applications
- 1 January 1948
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in Transactions of the American Institute of Electrical Engineers
- Vol. 67 (1) , 577-582
- https://doi.org/10.1109/T-AIEE.1948.5059714
Abstract
The carrier system described was developed by the Western Union Telegraph Company for use with microwave radio relay circuits. Thirty-two voice-band communication channels, each 3,000 cycles wide, are derived in the frequency range 4 to 147 kc. Tandem stages of group modulators maintain a high degree of spectrum efficiency and eliminate the necessity for crystal filters. A crystal-controlled harmonic carrier supply insures the frequency stability required by narrow-band frequency-modulation telegraph circuits.Keywords
This publication has 4 references indexed in Scilit:
- Filters for a 150-Kc Carrier SystemTransactions of the American Institute of Electrical Engineers, 1948
- A preview of the western union system of radio beam telegraphyJournal of the Franklin Institute, 1946
- Frequency-Modulated Carrier Telegraph SystemTransactions of the American Institute of Electrical Engineers, 1942
- Copper-Oxide Modulators in Carrier Telephone SystemsTransactions of the American Institute of Electrical Engineers, 1939