The "Everyman" Short Waver - Eddystone Short Wave Manual

EDDYSTONE SHORT WAVE MANUAL
THE "EVERYMAN" SHORT WAVER
A 4 -VALVE BATTERY RECEIVER WITH BANDSPREAD TUNING.
1 5 - 1 00 METRES.
Here is a specially designed short
wave
receiver which is simple to construct and
relatively inexpensive. An ideal set capable
of giving loud speaker results that will satisfy
the ardent short wave enthusiast.
The circuit has been based on that of the
Eddystone " Kilodyne Four," a set which
has already achieved a world-wide reputation
for performance and reliability. The patented
method of
bandspread tuning makes
the
receiver easy to handle and facilitates the
thrill of world-wide reception on the short
wave bands. The circuit consists of a high
frequency amplifier,
detector and two low
frequency stages.
It
is
free from " blind
spots " or hand capacity, and has smooth
and gentle reaction control. The set does not
re -radiate and can be used without any inter-
ference to the general domestic receiver.
CONSTRUCTION.
The wiring plan and point to point
con-
nection details make this quite straightforward.
It is best to proceed as follows
:-
Make up panel and baseboard
as shown
in sketch on page opposite.
Only simple
tools are needed and plywood will be most
suitable. The chassis or panel can, of course,
be polished to
suit individual
choice.
A
metal panel is not recommended, it may cause
hand capacity. The assembly comes next ;
but first for ease of wiring, it will be advan-
tageous to tin or give the connecting points
a coat of solder before parts are fixed in place.
Lay out components as shown in wiring
plan and proceed
to
fasten them down.
It should be noted that the coil base and valve
-
holder of V2 are mounted on insulating pillars.
When fixing variable condensers to panel
take care to bed down squarely otherwise
pointer may foul panel.
Make sure in the wiring that all joints
arc
strongly made. One poor or high resistance
joint can adversely affect the set's performance,
or alternatively may give the set a very high
background noise level whith is most unde-
sirable.
Baseboard view showing general lay out
of components.
BATTERIES.
A 2-irolt low-tension is needed, the Exide
D.F.G.
or
larger capacity being
suitable.
High-tension should be a minimum of 120 volts.
This can, with some advantage to quality, be
increased to 150 volts. The grid bias battery
should be 4i volts.
G.B. - 1 from the 1 meg.
leak goes to
the
1
volt tapping, G.B. - 2
from the transformer to 3 or 44 volts according
to anode voltage used. L.T. current is
.55
amperes and H.T. 12. m/a at 120 volts.
On
the battery leads there are two spade con-
nections to L.T. battery and two wander
plugs for H.T. battery.
TRYING OUT AND OPERATING
THE SET.
Insert a coil, and then starting with both
tuning, tank, and reaction condenser at
minimum, switch on the receiver.
Increase
the reaction control slowly by means of the
vernier knob until at a certain point the set
will begin to oscillate ; this will be noticeable
immediately, since a low " rushing " sound
will be heard. Throughout the whole tuning
operations, this reaction control should be
so
adjusted that the set is always only just in the
oscillating condition.
The reaction control
should never be turned any more than
is
ticessary for the first reaction sound to be