Eddystone Short Wave Manual page 37

EDDYSTONE SHORT WAVE MANUAL
3 5
ONE VALVE SHORT WAVE H.F. AMPLIFIER-continued
Low tension should be 2 volts, and H.T.
between 100--150 volts.
CONSTRUCTION.
The complete construction should take
only 2 or 3 hours and is easy to do by the help
of the lay out and wiring plan on page 36.
It is important that the actual components
specified should be used and the wiring should
closely follow that of the plan.
CONNECTING UP.
The unit has: teen designed so that a
crossfeeder..or interference reducing type of
aerial can be used. In this case the two leads
from such an aerial are connected to the two
sockets in the aerial terminal panel. The unit
also works perfectly with a standard aerial.
The only alteration when this is used is that
the aerial is plugged in the outside socket and
the other socket is connected to earth.
The
remaining terminal panel contains two sockets
which arc connected to the broadcast receiver
aerial and earth, as shown. The connections
arc exactly the same when the unit is used as
a converter or H.F. amplifier.
OPERATION AS HIGH FREQUENCY
AMPLIFIER.
The wave lengths of the existing set being
known, it is only necessary to tune the broad-
cast receiver to the desired frequencies, plug
in a suitable coil to the H.F. unit and then tune
unit until it is in resonance with the main*
AERIAL
TANK
4Turiai
HF.0
EDDYSTONE PARTS.
Battery Model.
1 Aluminium Die -Cast Chassis,
drilled
all
Price
necessary holes, finished inside and
out battleship grey cellulose,
Cat.
No. 1059
.. ..
12/9
1 Metal Panel,
finished Dark Crystalline
Brown, Cat. No. 1058
..
2/9
1 Bandspread Condenser Unit, with Slow
Motion Head, Knob, Dial
and
Cursor, Cat. No. 1043
..
6/6
1 Patented Tank Condenser with Knob and
Graduated Dial Plate, Cat. No. 1042
6/-
1 Chassis Type Valveholder, 7 -pin, Cat. No.
985
..
1/4
1 Chassis Type Coil Base, 6 -pin, Cat. No. 964
1/3
1 Screened H.F. Choke, Cat. No. 982
5/-
1 Small Pointer Knob and Dial, Cat. No. 1044
1/-
1 Filament Choke, Cat. No. 1062
..
3/6
2 Terminal Panels with Plugs and Sockets at
9d. each
..
1/6
1 Metal Cabinet, Cat. No. 1061
..
9/6
1 Set 6 -pin Type Coils, Cat. No. 1064. Set of
3 Coils
.. ..
..
12/ -
Total, i3 3s. ld.
MISCELLANEOUS PARTS.
1 T.C.C. 0.1 mfd. Tubular Condenser, wire
ends
..
.
.
1 Dubilier .0001 mfd. Type 670 Condenser
1
Erie 50,000 ohm Potentiometer
1 Erie 20,000 ohm Resistor
..
1 3 -point On -Off Switch
..
18 i" x 6BA R.H. Screws and Nuts
. .
1
yards 4 -way Cable
1 pair Red and Black Spade Terminals
1 pair Red and Black Wander Plugs
1 Anode Clip (Clix)
.
.
2 yards 18 gauge Tinned Copper Wire ..
1 yard 3 mm. Flex Wire, Soldering Tags,
Washers, etc.
Approx. Price, 13s. 6d.
VALVE.
Mazda SP.210, 7 -pin, Metallised
.
CatNo.982.
.000i/ed.
----11555ger
RFC.
50,00011
HT+
20,000.11.
° INPUT TO
LT+
HT
THEORETICALCIRCUIT DIAGRAM FOR BATTERY UNIT.