By Enrique A. Wembagher, Argentina
hcdx web, 30 September 2002
This project was built to be able to experience with more of an
antenna and also in turn to be able to have a system that offers
security to the receivers, carrying out the discharge to ground
of the antennas.
I suppose that many of you will want to already experience
with another additional antenna to the installed; this selector
gives solution to the situation it inconveniences of to unplug
and to plug connectors losing valuable time.
The same one can be used as much as for longwires, dipoles, etc.,
although it could be special for longwires installed with different
The solution is very simple with a single switch, but I also kept
in mind the security, because in these times "crazy" plagued of
atmospheric storms, it can also happen that we receive discharges
that for minimum that are they can end up damaging the circuits
of entrance of the receivers, like Sony ICF-2010´s usually happens
in those that many users burned for overload in the antenna to
the transistors of field effect that are to the entrance of the
reception circuit, without knowing that these they are damaged
the receiver since equally it works but with a diminished reception.
that is shown is extremely simple and it works in such way that
you can connect an antenna or other and also both (it is single
question of experiencing) with the extra attaché that in position
(OFF) of both switch, the antennas are connected to ground and
at the same time they disconnect the receiver achieving the wanted
The materials are of easy acquisition and the switch can be of
the type switch of "combination" that are used in the electric
facilities or some other one that you possess.
I should indicate that the switch carry out the connection
internally from an inverse way to the position of the switch (of
this they don't worry), in the figure they are indicated pressed
the switch in position OFF, which is the suitable one to leave
to our receiver when we don't use it, this way they were the connected
antennas to ground.
In position ON of the superior switch, will only be connected
the ANTENNA 1 and the ANTENNA 2 it will continue connected to
ground, the procedure to the inverse one will carry out it when
they want to only use the ANTENNA 2.
You will be able to carry out the project to their way, that is
to say placing the necessary connectors and switch, mounted in
a plastic box or of aluminum and carrying out the connections
preferably with coax cable, being housed in a comfortable way
for their handling.
They should remember that it is indispensable to have a good setting
to ground in all reception system to obtain a decrease of noises
and to achieve good receptions.
For extra protection, add two diodes 1N4148 in output to the receiver.