New-York tribune., 1922-09-24

| has been set aside each day for expert
mentation. particularly with the three
tube super-regenerative circuit.
| The various parts comprising the lat
! ter have been assembled on base ff-
| teen inches by ten, and it is expected
| that within short time we will be able
/ to describe in detail the constants for
| this set with only two controls. The
| description will also include the meas
urement and layout of the panel.
| During the week the following sets
! and parts were thoroughly tested and
approved by the institutes:
Variometer Variocoupler Set
| This set consists of a detector tube
/ the grid and plate circuits of which are
tuned with variometers, and the induc-
| tive coupling with the aerial made with
a variocoupler A potentiometer is pro-
vided to maintain the desired voltage
on the in-put circuit, and WERNER rheo-
stat for close control of the tilament.
! The whole apparatus is installed within
dull walnut-fnished cabinet, 2G
inches long, 7la inches high and ~
| inches deep.
Mounted upon a black composition
panel in the front of the cabinet are all
the control elements. The terminals
| for the "a" and "B" batteries are ar
ranged upon an insulative strip in a
vertical row on the right rear side OF
| the cabinet An aluminium shield is at
| tached to the inside of the front panel
| to minimize the effect of the body
capacity during control. All lntercon-
nections are made with heavy tin cop
per wire, bends squared and JOINTS well
| soldered.
The rotor and stator of the two variom-
eters are wound upon black compost
ton moulds and contacts between the
two elements are. made with heavy
spring clips. The windings of the varlo-
coupler are upon similar. material, and
all leads from the primary coupling are
! soldered at the points of the contact
switch.
The apparatus is accessible through
door at the rear of the cabinet stand
ing its entire length. This set is capa-
| BILE of very close tuning and, II prop
erly handled. will give better results
than the ordinary single tube regenera-
| tive set.--Made by the Pennsylvania
Wireless Manufacturing Company, New
castle, Pa.
Single Circuit Regeneratiye
The primary inductive circuit and
| ticker OF this set are of fixed relation
and wound upon a black composition
| tube 31h inches In diamter and the
same in length. The ticker consists of
approximately one-tifth the number of
turns used in the primary winding and
both of these windings are of D. S. c,
copper wire.
Across the primary winding is 29
plate condenser for tuning purposes
Fixed condensers are used in the grid
circuit and across the phones, This set
is also provided with veneer rheostat
| ip,y, of fnts for \, n
proper voltage on the feed-bac cir
cult. The cabinet in which the appara-
tus is installed is 121a inches long, TX
inches high and 71a inches deep.
A 3-inch dial mounted son a black
composition panel inserted in the front
of the cabinet controls the condenser
and below this are two contact point
switches--the coarse adjustment switch
having five points, and the fine one
four. On the right side Of the panel
are mounted the contact switch for the
potentiometer and the rheostat knob
the former above the latter. Input
terminals are provided at the lower left
hand corner OF the panel, and those for
the phones are at the lower right.
Similar to the "F" type, the "a"
and "B' battery terminals are mounted
on an insulative strip on the right
rear OF the cabinet. The interior of
this cabinet is accessible through a
hinged door with spring lock-Made
by the Pennsylvania Wireless Manu-
featuring Company.
Two-Stage Ampiifier
This unit consists of two stages of
audIo-frequency amplification and is
! designed to be connected on the ont
put side of either of the other two
detector units.
The cabinet is of the same CON
stfuctlon and cross section dimen-
Sons the same as the other two types
and l212 inches in length There are
no adJustment knobs on the front
panel the hlament current contro
oelng obtained by two ampereite plugs
IN series with the plus" side of the
filament
The sockets are mounted upon q
strip of insulating material at tbe
bottom OF the cabinet; and two Acme
! audlo-freQuency transformers are fas-
, tened to the front panels. Between
the latter are two audio-matic fila.
meht control jacks which allow the
use OF either one or both stages. All
lntefconnectlons are carefully made
, and soldered, except where screw bind.
, ing posts are used.
, To attach this unit. to either .,
: ,he detector sets, connection is made
between the two output terminals al
the lower right Of the detector set anr
in-put terminals at the lower left o.
the amplifer. -
battery connections are made te
terminals at the lower right of +be
front panel and those for the "B" hat,
! terry are made at the left rear.
The interior of the cabinet is a.
cesslble through hinged door At n.
: rear as in the case of the other WV
, sets'.Made by the Pennsylvania Wire
less Manufacturing Company.
/ Variable Condenser
= Inc grade of materials used in tbi,
{ condenser and its finish are of m
usually high quality. The half dist
! OF the rotor are inches in diamete
r and It's Il plates are distributed owe
a length Of 2A inches.
t The half disk end supports of tb,
stator are 31s inches in diameter an;
OF thick brass plate, heavily nickeled
; Likewise, the spacing washers betwee,
plates of rotor and those of stator mr.,
. of nickeled brass. The rotor shaf
revolves in an insulative beariny ron
sisting of II inch disk of thick blacl
composition screwed to the outside O.
the end plates.
lnsulatiye stubs are provided at til.
lower end of the condenser for mo ,,,t
ing 1T in vertical position, and ther.
art three nickeled brass studs with in
set screws for fastening to the from.
panel If desired
The connections 20 either side of tn,