were a real breakthrough in achieving frequency stability in harsh
environments that included mechanical vibration, temperature excursions,
power supply variations, and load changes. Use of vacuum tubes made
the task even more challenging. Such oscillators were necessarily
very expensive compared to less sophisticated designs. Henry E.
Rice Jr., W9YZH, introduced his "Rice Variarm" model (aka the Millen
Model 90700) at a breakthrough price of just $29.50, which in 2013
money equates to $469.89 per the U.S. BLS
Inflation Calculator. That is a lot of moola for amateur radio
operators even today. The arm sticking out of the case is for adjusting
February 1941 QST
articles are scanned and OCRed from old editions of the ARRL's QST magazine. Here is a list
of the QST articles I have already posted. All copyrights are hereby acknowledged.
Something Radically New in ECOs
There are many approaches to the ECO design, most of them
having been described in the past; such as expensive, ruggedly-built
h.f. oscillators with their external regulated power supplies, low-frequency
dual heterodyne oscillators, etc. All have their merits, but are
necessarily expensive to manufacture and must ultimately end up
by selling in the 50 to 60 dollar price bracket.
A new approach
to this problem has been evolved by Henry Rice, Jr., and was described
in detail in January OST. Probably the outstanding feature of the
Rice development is its high-performance-per-dollar which makes
possible a factory built commercial ECO with modern performance,
complete with tubes, ready to use, for less than 30 dollars!