Eddystone Short Wave Manual page 5

EDDYSTONE SHORT WAVE MANUAL
ALL WORLD TWO-continued
The tank condenser spindle should be
turned until the moving plates are fully out
of mesh with the fixed plates and the pointer
knob fixed opposite the 0 division on the scale
by screwing up the small grub screw.
By
turning the knob clockwise, the condenser
will rotate in 10 steps up to the maximum
capacity.
Turn the reaction spindle as far anti-
clockwise as it
will go, and fix the pointer
knob so that the pointer is placed at the posi-
tion which the small hand of a clock points
to at eight o'clock.
:
It is advisable to leave the tuning con-
denser off the panel until all the wiring is
finished. This enables the chassis to
be
mounted upside down on the edge of a table
to facilitate wiring. Wires Nos. 9 and 10 may
be connected at one end, but the free ends
left until the rest of the wiring is completed.
Certain
condenser and resistances
not
already assembled are automatically supported
by their connections, so the wiring may now
be commenced, and should be carried out
without difficulty with the aid of the wiring
plan on centre pages and point
to
point
connection list on pages 4 and 5 overleaf.
VALVES.
The kit has been designed around the
Mullard SP2 Screened Grid andllazOa`sP32.9
Triode valves. The constructor may use any
of the two other triode valves specified or
alternatively one of the three pentode valves
listed
below.
The average total number of milliamps
for any of the pentodes or triodes are given in
the right-hand column below, from which
it will be seen that the use of the pentode type
of output does not increase the consumption
of the receiver, but does in practice consider-
ably add to the signal strength.
A five -pin valveholder is fitted in the
output stage, the centre pin automatically
connecting the auxiliary grid to the H.T.
supply when a pentode is used.
An automatic bias resistance. is incorpor-
ated in this receiver, and it has been dalculated
to be equally suitable for the following output
valves :
Total_ Milli -
(a) (b)
amps with
TRIODE
PENTODE
Detector Valve
VALVE (7;-) VALVE (13/6)
(a) (b)
Mazda P220
Mazda Pen. 220
4.5 4.8
Osram LP2 Osram PT2
4.55
5.1
Mullard PM2A
Mullard PI1122A
4.55 3.95
RESISTANCE COLOUR CODE.
Resistance
Body Tip
Dot
CONNECTING UP.
Place the desired Coil in the coil base, a
Mullard SP2 Valve in the first valveholder V1,
and the appropriate Output VAlve in V2.
40,000 ohms
Yellow Black Orange
Use a pair
of 2,000 ohm headphones
in
100,000 ohms Brown
Black Yellow
the 'phone sockets and connect.- aerial
and
I meg. ohms
Brown Black Green
earth leads. Put the on -off switch in
the
3 meg. ohms
Orange Black
Green
" off " position (turned left) and connect up
1,000 ohms
Brown Black
Red
the H.T. and L.T. batteries.
V
.4150
5
70, 140 sofq
000
W.
TUNER
100,000 CA.
002,a0d.
IF
V I
40 00011.
THEORETICAL CIRCUIT.
PHONES
1
ooapPd.
I
H:r+
000
SWITCH
o H77.-
LT.-
o LT. 4-