The Challis messenger. (Challis, Idaho) 1912-current, 1925-08-19
BY CAPT. p. v. o'RoURkE,
In Radio World.

Gun give BOOu SelecIlVlty ana VO
ume. They do not want regeneration
because the set is for general famil
use, including children, and they ar
afraid that lack Of care In tuning vii
cause neighbors considerable annoy
ance. And, besides, the controls ar,
limited by the inquirers to only two
on the plea that no member of the
FAMILY has more than two hands
1t Is really surprising that so little
attention has been paid generally to
the hookup. which Is probably the
most stable and satisfactory three-tube
reflex that you could build for aerial
operation. Factory-made products,
using only three tubes, may accom-
pllsh more, because reflexing, espec-
Tally Inverse redexing, is fine art.
But the set shown will cause no trou-
Bile, either during building or after
ward, and reflex with the trouble
element taken out must indeed tie In
wiling
List of Parts.
Two radio-frequencyA transformers,
L1L2. L3L4
Two .00O5 MID. variable condensers,
CT. C2.
Three sockets
Two A inch dials.
Two dial pointers
Three IA Amperites (for 2O1A !
tubes).
Fixed condensers. CO, .OO025 MID
"a, .0O01 MID; CO and CO, .OO1 mid.
One 2-megohm grid leak. RI.
Two audio-frequency transformers.
One single-circult Jack.
One battery switch, S.
One by 10 inch panel.
Accessories: One by 17-inch base
board aerial wire, ground clamp.
lightning arrester, lead-in wire cabi-
net, speaker, A and b batteries. Jack
plug, four wv 201A. 3O1A or DV2
tuoes' terminal strip. internal con-
Meeting wire, hardware. =
Set Needy No NeutraIizIno.
Why no neutralization2 you may ask.
First, because none should be neces-
sary with only one stage of radio-fre-
quency application. It's the second
RF stage that compels the inclusion
Of some stabllizlng device, like bal
ancing condenser potentlometer, plate
resistance or the like. If by any
nance oscillations do occur where not |
would be only below
loO meters-the neutralIzing conden-
er may be inserted. However. have
'uiit several Of these sets; neutrali-
ation never was necessary, hence l.
vii not include directions for neutral r.,
cation tap, etc.
Ihere are only two coils to make,
ne for the aerial circuit (L1L2). the
ther for the interstage coupling me
L3L4).
This circuit is characterized by
'eedom from squawking, freedom {
'om difficulty In construction or oper- {
lion, and freedom from excessive {
lmber OF controls Therefore it Is I
llled the Freedom reflex, which has v
timely touch to 1t. too. sho
NO rheostats are employed, the re- wv
stance elements in the .flament of
nus lead being amperltes suited to by-l
tubes employed. 1t is all right to Ais,
uhe amperite In the detector not
'ge OF this circuit. Thus one gro,
Itch controls the entire fllament the
hting' AS the set Is designed for Trit
eaker operation, no phone jack Is
)vided
The Panel. III
The set may be constructed on a
" IL inch panel. The panel may be- A.
ided horizontally, with line Z SOW,
os co. ~ -. 'ne ,op' anu tne center avoi,
inches from extreme left and ex- =
me right. respectively. The only
ects appearing on the panel are the
ten ). the dials and the jack. The Hol
ten may be of the push-pull tyne. VIE
II you can get the toggle kind with ~
mali mounting hole required, that
KS more smoothly. The usual toy
switch Cleft and right or I'D and
n motion) requires too big panel
; inch or so, and few have the
rument necessary to drill this, or
Tor such big dent" In the
i.
re switch should be placed at a
near the A-plus line to the ter
strip (binding posts). How
e aerial coil Is made of No. o2
re cotton covered wire on 31a
diameter, either tubing or basket Ing tut
e. Ii consisting Of II turns and end.
I 43 turns. each winding sepa- clear v
and distinct, and the separotion gest
zen n inch. LS Is wound also
on inch diameter, consisting of
rms or the same kind of wire. Ono
one...,o -, aiter the set radio c
gha- AZ, ioanu mat VI round-n
: 80 ss tnan " then type 20
- d,s,. ~ IVY from "a. until shape d
.onsa. a' ,ose'ner' Inc va on their
nana .S snouio De OF the ing post
~ ~apacity' 'VOU0 MD supplied