Above is a typical circuit that as a young adult I constructed
to listen to a couple of local radio stations
and I think it cost me about four dollars then ,maybe it would
now cost ten or eleven dollars now.
All parts can be readily obtained from your local electronics
or hobby shop. (Dick Smith and Tandy in Australia)
This circuit would have been know to Nicola Tesla as he design
a similar circuit .
Normally you would only use a small ferrite bar for the coil
or indeed only an air coil inductor winding.
Many would have only built them to receive the local radio stations
twenty miles distance or less but more than this can be
accomplished with just experimenting with the coil winding sizes
and longer distances covered..
By winding just one loop to many loops around the suggested ferrite
rod size many shortwave stations could be heard and in some instances
the tuning capacitor could be done away with.
The constructor normally be told that a high and long antenna
and earth are required but below I described a aerial
that requires no more than six feet of zip cord or twin lighting
flex.
Please note I take no responsibility if you construct the above
and you construct or put it together incorrectly
and you should do so under adult supervision ( by the way the
idea does work)
Putting it together.
DO THE FOLLOWING ONLY UNDER ADULT SUPERVISION
Obtain for yourself a NEW six foot length of twin flex
from each end and at opposite side remove six inches of the flex
cord as in illustration.
from the length remaining cut away an inch of insulation to leave
the wire.
At this stage and this is important
Test to see that you have no conduction between the two bare
wires at each end of the zip cord.
This can be done with a multi meter tester or a torch globe
and battery.
If the meter zeros out, or the globe lights up , assuming
the bulb is working then do not use this cord and try and make
a new one again.
DO THE FOLLOWING UNDER ADULT SUPERVISION
The plug diagram is an Australian wiring standard and may be different
in other countries so check to see and be sure what you are
about to do.
Be sure to wrap insulation tape where wire has been removed
at the six inches cut mark for extra safety
Remember one of the wire Leads will be live with electricity
,so keep it away from water and skin contact.
Connect one of your bare on inch wire lengths to the active side
of the electrical plug and place into electrical power point
and the other end to your receiver ,be it a crystal radio or a
normal radio or even a TV and then listen to your receiver you
will be to hear a strong clear signal if within range of transmitter..
Please note TV reception has a limited range.
This can also be connected to an electrical light fitting and
get the same result.
Don't use the earth connection on the plug just in case your
home has been incorrectly wired and your earth has power
running through it.
If your house has installed wiring by a licensed contractor he
is likely to have done this correctly.
HOW IT WORKS
Around us at all times there are radio signals these interact
with any long leads and overhead power lines are no different..
The radio signal travel along these lines and into your home why
not make use of these.
The zip cord acts as a signal transformer and places the signals
from one side of the cord to other cord on the opposite
side and these are fed to your receiver..
I have received short wave signals on a simple crystal set up
as of the first above diagram from 1000 kilometres away
The information is supplied as an Educational reference only and
no responsibly is taken for anyone actually using
this information to make this antenna.
Remember Safety first at all times.
Geoff
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