New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1922-07-02
How the New SuPer-Regenerative
Circuit Is Tuned and Operated
Detailed Description of Parts in Major Armstrong
Latest Creation, Also the Correct Method of
Placing 1t Into Receptive Condition

The operation Of the Armstrong
super-regenerative circuit is extremely
simple, and once the circuit has been
placed in a stable condition there are
only two actual adjustments to make.
The diagram which is produced on this
page to-day shows the best method of
using the system for the purpose of
radio-phone entertainment reception.
The loop aerial can be made on a
threefoot frame wired with twelve
turns of No. IS cotton-covered bell
wire, each turn spaced one-eighth of
an inch from the next turn. The
ends of the loop are connected in par
allel with the coil marked Ii in the
diagram, and it is tuned into resonance
with the incoming wave by means of
the condenser, CT. This arrangement
forms the oscillating circuit. The loon
can also be placed in series with the
coil Ii if desired. The tuning will re-
main the same.
The first tube is the regenerative
tube and the coil LIZ is the ticker. It
can be of fixed value and can consist
of the secondary of the regulation
varlo-coupler, but it may be necessary
to place double the amount of turns of
wire on it.
Varies Only With New Tube
The condenser CO is made variable
in order that changes can be made in
the tuned circuit about the second
, tube. These changes will be necessary
only in case new tube is placed in
that circuit and in the event that the
tube has different characteristics to tn
original tube.
The circuit L3, CO, Ia, Is and ca is
the oscillating circuit for producing
super-audlble frequencies which con-
trol the negative and positive resist
ance of the circuit, and the tube used
in it is the oscillator, but it also per
forms the function of a detector as
we'll.
Behind this circuit Is the filter sys-
tenn, which has for its purpose the fl
tratlon of the high pitch note caused
by the 2O,000-cycle frequency at which
the second tube is oscillating. With
Wv eHio HiLeI system Cne Chlrd tube
would be paralyzed and nothing would
be reproduced in the telephones.
Resistances of Lavite
AS stated in the description, the two
reslstances are each of $4,000 ohms in
value. They are composed of lavite,
and are fixed in value. The condenser
20, by an error, was shown in the dia-
gram as being fixed. 1t is in reality q
variable condenser, but once il ha s
been adjusted to take care of the stu
alton it need never again be touched
Any of the standard audio frequency
transformers can be used for T.
Inc iron core choke coil is of stand
ard 'design used in regular telephone
communication work for filtering pur-
poses. Its value, however, should be
that shown under the diagram.
Now in the actual operation of the
circuit the first thing to be done after
an the parts are connected is to adj
Just the condensers CO and C5 to
their permanent position. The tubes
are, of course, lighted by means of The
f!ament rheostat to the proper depree
of brilliancy.
AS soon as the permanent parts Of
the circuit have been made stable
there remain but two adjustments n
make at any time. First, the wave.
length adjustment, which is obtained
by varying the condenser CT, and The
second is the amount of feed-back ~