Wednesday, February 9, 2011

Anti-Jamming Antenna (and it really works)



If anyone can access this blog and are in an area where jamming is focused against broadcasters like the Voice Of America, BBC World Service and others there is a quick and easy way to get around this and improve your reception. These plans come from the Broadcasting Board of Governors, which oversees the Voice Of America.

Last summer I built it myself to see the results and I was amazed. It really works and does improve stations being jammed by the Chinese. Of course it does depend on propagation, but it does work. It took me less than an hour to build and I used stuff that I had around the house. Above you will find a diagram and picture how it should look. I came across these plans on the BBG website.

Materials:

A compact portable receiver radio with its telescoping whip antenna

An additional telescoping whip antenna similar to the one used with the receiver radio or a stiff wire

Two pieces of aluminum foil having same width and length as those of the portable radio receiver

A clean piece of plywood or equivalent, non conducting of electricity, big enough for overall support

Two short pieces of connecting wire with screws for connection as required

A block of wood or equivalent to support the additional antenna

Installation:

On the piece of plywood used as overall support, lay the radio receiver on the first aluminum foil pad. Use a rubber band or string to secure the receiver if desired.

Fix second antenna into wood block so it stays vertical.

Connect the additional telescoping whip or stiff wire to the foil pad on which the radio lays. A small screw can be used to attach the first connecting wire to the aluminum foil.

Wrap the other bare end of the wire around the whip and twist the wire to assure that a good electrical contact with the whip is established.

Use the second wire to connect the remaining aluminum foil to the telescopic whip of the receiver as described above.

Operation:

The interference reducing antenna should be operated in a relatively clear area. It works best when people are not near the antenna.

The interference reducing antenna is operated by rotating the whole system, receiver and the two whip antennas together with the plywood support, until the interfering signal is minimized and the desired program is as clear as possible.

If the desired program cannot be received clearly by rotating the plywood support when the interference reducing antenna is level, then try slanting each of the antenna whips or both, and then rotating the system again. Keep experimenting with different slants and rotations combinations until the desired program clears.


2 comments:

Anonymous said...

Any receiver can use? Or only one in picture?

Anonymous said...

The best kind is a small portable like the one seen. So in answer to your question yes.
Keith