The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1925-08-07

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the connection to the neutralizing con-
densers.
The single winding on the aerial coll
works very well, but little more Sc
lectivity will be obtained by following
the diagram. with the two windings
separate.
The coils are wound under two and
over two" When the winding is fin
ished the coil may be raised about
] inch from the form and cord In
serted in wave form through the.
inside length of the winding and knot
ted for security, or the cord may be
employed in any other fashion for
support
The coils are removed from the form
after this lacing is completed. L1L2
is mounted on the Dashboard at least
2 inches in back of CT, the coils axes
parallel to the Dashboard (windings at,
right angles to baseboard). For this
purpose two dowel sticks may be used.
reinserted at two adjacent holes in
the winding, using two Pinch hard
rubber or brass right angles, secured
TO the Dashboard and to the dowel
sticks. L5L6 is mounted in the same
way. L3L4 is mounted with its axis
perpendicular to the Dashboard, the
more conventional fashion. Thus adj
Joining coils are at right angles to each
other and magnetic interplay is sue
cessfully avoided
Place all the instruments in their
respective places, taking care that the
RIFT are all near their own sockets,
so as to have very short leads, and
thereby save some energy.
The Wiring of the Set.
Bring the beginning of the wire OF
IL to the antenna post of the ter
minal strip and the end of the coil
(this being the ten-turn primary to
the ground. Connect the beginning of
the secondary coil Ii to the stationary
plates of the condenser, CT, to the
grid post of the socket, and to one
end of the neutralizing condenser, CO,
the end of CO going to the fifteenth
turn tap on the coil, Ia. The beginning
of the coil, L3, goes to the plate post of
the first tube socket, the end of this
coil going to B plus post (67h volts)
on the strip. The end of ID goes to
the rotary plates of the condenser
and also to the negative side of the
A battery, and to one end of amperite.
If you desire to obtain volume and
bit less selectivity, connect the end
of Ii to Ii. The beginning of LA
goes to the grid post of the second
tube and also to the stationary plates
of the condenser C3 and also to one
end of the neutralizing condenser, CO
(this is the second one), the end of
LA going to the rotary plates of CO and
TO the end of the amperite which in
! turn goes to the A minus. The begin
ming Of L5 goes to the plate of the
second tube and the end goes to the
same place the end of L3 went to,
that Is the B plus 6712 volts. Bring
the end of the second neutraliZing con-
denser to the fifteenth turn of 16, the
beginning of the coil goes TO one post of
C5 and also TO the stationary plates
of CA. Bring the end of the coil to
the rotary plates of CA and also to
the post of the leak, and finally to the
A-plus and B-minus post of the ter
minal strip. The left-off terminal of
the grid leak goes to the left-off ter
minal Of the C5, which In turn goes
to the grid post of the detector socket
(the third tube). Note that all the
amperites are placed in the negative
lead of the A battery and the detec-
tor rheostat is placed in the negative
lead, to same, the only difference here
being that the grid return is put to
the positive side of the low potential
line instead of the negative as was
done with all the grid returns of the
other tubes
The @ battery is inserted in the f
leads of the AFT, which go to the
minus side of the @ battery, the pos
tive side of the c battery going to
the switch, eventually to negative A
battery.
The set is designed for earphone use
only to facilitate tuning, otherwise al
ways for speaker use. If earphone
service on regular reception is desired.
luSeII duOlHcT SWItCu UStWeSu the
filament side Of 81 and the battery
side of the audio amperites
How to NeutraIize the Set.
Naturalization is simple process of
follow out, but it takes little time to
get it just right. Put a small piece of
paper between one Of the filaments of
the second tube from left and the
spring on the socket Push the fla
ment switch out and light the tubes,
then tune in loud local station. If
you hear the least undertone of sig
nal, there is some interstage coupling
present. Adjust the small neutraliz-
ing condenser until this signal disap-
pears. The same procedure is fol-
lowed out with the first tube (extreme
left). Both settings are left perma-
nently and should never have to be
touched. except If the ground is
changed, which may change the APP
parent capacity of the tubes through
the interchanging of current from the
coils. and which in turn will change
the capacity effect of the neutralizing
, condensers.