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
Inflation Calculator. That is a lot of moola for amateur radio operators
even today. The arm sticking out of the case is for adjusting the frequency.
February 1941 QST
of Contents]These 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 (if any) are hereby acknowledged.
See all available
vintage QST articles.
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!
Posted November 6, 2013