Stenode

The stenode or "Stenotube" (Lafayette 10th Anniversary catalog page 34 from 1932) is the heart of the Stenode circuit and consists of a quartz crystal ground to 175 kc, mounted in tube form for easy handling. Standard UX socket base. James Robinson, then engineer fo the "Receptite Company" of London, England, is the inventor. The Stenode was offered by Lafayette in 1931 for $ 14.70 - which then was really not cheap!

In October 1930 Radio News brought an article for the "Stenode Radiostat" which should have "completely altered the future of radio": Just ahead of the second detector of a Superheterodyne is used a triode instead of a screen-grid tube for the superior power-handling of the triode. "The quartz crystal is used instead of a number of sharply-tuned cascade resonant circuits in order to obtain high selectivity; and that used in the Radiostat has a decrement of the order of 0.00004. It is obvious that the selectivity given by such an arrangement is much higher than could be easily obtained by a more normal method of cascade tuned circuits. The band width passed by this crystal circuit is only about 50 cycles; consequently any interference on a frequency different from the frequency of the desired station by more than 50 cycles should be completely eliminated."

Stenode: Fin Stewart Fin Stewart
	Just Qvigstad	Stenode: Fin Stewart Fin Stewart More ...

Collection of