Belt Valley times. [volume] (Armington, Mont.) 1894-1977, 1926-02-11
SEE.S AlgAE
= 49, : ga q
Action, Stability
In Eive-Tube Set
Receiver Using Basket.
Weave Coil Mounted Be
hind Condensers.
BY CAPT. p. V. o'RoURKE
b Radio World.

IN Nduto WCFto.
The standard hte-tube tuned RF
set Is shown In the diagram. The
receiver uses basket-weave coils that
are mounted behind the tuning con-
aensers. This introduces an action
In the circuit which tends toward sta
bility Unless this were done the
tubes on the radio side would be
uncomfortable.
AS a further check upon disastrous
action by the radio simplifying tubes
the rheostat controlling the two RI
tubes may be varied. The greater the
resistance OF the rheostat In the cir
cult, the less brightly the tube burns
and the less oscillation.
Fits On 7 by 10 Inch Panel.
The set may be constructed on q
by Is inch panel. A convenient
method Of assembly Is to use a socket
shelf. There is just enough room for the
coils behind the condensers Angle
irons are used to secure the coils to
the socket shelf. Although called
irons. they are most commonly brass.
A tubing, Is inserted through one OF
the apertures caused by the method
Of winding a basket-weave coil. This
aperture formerly was occupied by a
dowel stick or other rod Of the wind
ing form. Inside this tubing a long
machine screw Is placed, with thread
toward the condenser. so that a nut
may be affixed at that end. to clamp
the screw down upon the brass angle.
The other end OF the angle Is afflxed
to the socket shelf. Usually one
angle, bent like an L,-wlfh a short
horizontal plane as the base. is sutfi-
Client for each coil.
The Coils.
The inductances are alike In con-
struction The primaries have eight
turns and the secondaries have oB
turns. The wire Is No. "a enameled
silk covered. The form diameter Is
three and one-half inches. Usually
there are IS rods on which the wire
Is wound. these constituting the
form.
turns. then the primary wire ia picked
up and wound along with II, side by
side, for eight turns. The primary
winding being terminated then, the
rest OF the secondary (25 more turnsl
is put on. The small primary Is used
as further aid In obtaining a re-
ceiver that will not cause trouble
some oscillations.
The set, made under these dlrec-
lions. with .000S5 mid. tuning con-
densers, viii tune approximately in
step. One factor that tends to OPP
crate against this is the added ca
pacity In the first radio transformer,
Liz, due to the battle-ground sys-
tenn. Thus CT might tune with
readings a little lower than those OF
the other condensers To get away
from this four turns may be removed
from the secondary Of the first radio
or. in the actual winding,
the number of turns might be made
four fewer than that on the other
secondaries q. e.. 80 instead OF 56).
The circuit enables one to use ear
phones at the detector output but the
Jack providing for this purpose, il,
Is to facilitate the tuning In of dis
tant stations, and not for general
sarphone reception. On that account
the rheostat that controls three tubes
the detector and two audio-has no
auxiliary switching arrangement. That
e. when the detector tube Is lighted
the audio tubes must be lighted
otherwise there would be something
wrong with the wiring. II the diagram
we're the guide. j is for insertion OF