The Challis messenger. (Challis, Idaho) 1912-current, 1925-12-23
Wiring Diagram FourTube Stage
f..

outer end connects to the plate tie
minal of the radio-frequency amplifit
tube. After the set has been tested,
may be well to try reversing thes
connections.
The nine-turn winding which follow
the direction of the secondary Is COZ
nected In the plate circuit Of the de
tector tube. When the circuit
under test. If 1t regenerates or squeals
this coil Is wound too near the sec
ondary. Slide this coil away from tn
secondary another quarter inch. Thi
will prevent the regeneration to thu
extent Of stopping oscillation. There
will still be certain percentage o.
regeneration present which Is neces
sary in order thss the receiver func
tion on distant stals<sns. However, the
set should not squeal on any wave
length. 1t will not rkdiate, due to
the blocking effect OF the stage of
tuned radio frequency.
&c" Battery Is Included.
A &c" battery seems to be in style,
and so one has been included In the
circuit. 1t will improve reception as
well as prevent excessive drain on the
plate batteries. Ninety volts "B" bat
terry will require &c" battery of As
volts. If one Of the new RCA power
tubes Is used in the last stage a great
Increase in volume over the 2O1A will
be obtained
A word or two of explanation con-
corning the tuning of this receiver is
given to enable those who have con-
similar outfits to obtain the
best Of results. There are but two
as far as actual tuning Is
One of these to the left
IF the panel is employed to tune the
1rst stage of radio-frequency and the
intenna circuit. The second tuning
condenser Is used to tune the detector
,ircuit This adjustment is In control |
# the wave lengths and may be called |
he station selector," as it Is used 60
lick out the stations. If the set has
zen properly constructed, this tuning
ial should be fairly sharp on all sta
Ions. 1t may be logged
The radio frequency coil is wound
n 3-inch tube about 6 inches long.
10. "a double cotton or silk-covered
ire Is required for the winding. The
ntire coil contains 80 turns of wire,
18th A taps take-off at intervals. Start
he winding about half an inch from
he end of the tube, and before taking
lie first tap. wind so turns of wire.
AXE loop or twist which may be
eaned later for connections. Contin-
} winding the coil in the same direc-
On until the SEVENTEEN turn. Take
lother twist and proceed to the
ghtieth, where another tap Is taken.
nish the coil at the ninetieth turn
ID leave short end for connecting
Q bus bar wire.
Two small brass braces can be
rewed to the bottom of the coil for
lding 1t In an, upright position on
E dashboard.
This coil should be placed directly
back OF the aerial tuning condenser
d about an Inch away. The .OO0s
riable condenser which tunes this
! is connected to the top turn. This
'uld be made to the fixed or sta
nary plates Of the condenser, In or
to avoid any possible "body ca
'ity." The rotor plate connection
8 to the antenna binding post on
p at the rear of the Dashboard.
Connects to Grid Terminal.
he top of the coil also connects
the grid terminal on the radio-fre-
ncy tube socket. Make tie lead
short as possible and direct to the
xet. avoiding bends and fancy
ped wires.
he antenna series condenser aid.
bringing about resonance between
primary radio-frequency circuit
the detector circuit The adjust.
t of this dial may not be so crit.
as the other dial across the sec.
Try tuning condenser. 1t may be
to experiment with the taps on
roll winding Pick out tap which
give dial reading on the antenns
enser which takes in wave lengths
zen 200 and $50 meters. 1t is
'ult to state offhand which tan
be correct. Once the proper tur,
Gated the lead wire to the con
er may be fixed permanently. In IN,
cases. however, 1t will be found ali,
efficient to try fewer turns when ed
g to some Of the stations around nor
meters or thereabouts. Too MANY viii,
may cause tuning on the shorter eufr
to be trifie sharp. 1t is DOS inc
to log this dial as well as the =
q
INN