If you have purchased an all-wave radio and want to listen to long-distance, medium-wave and short-wave radio stations, you will need to equip your radio with an external antenna. Such an antenna will allow you to experiment with a detector receiver.
It is necessary
- - wire or antenna cord;
- - insulators or rollers for electrical wiring;
- - tools for soldering;
- - pliers, wire cutters;
- - plexiglass, fiberglass;
- - drill with drills;
- - neon lamp;
- - switch-type switch.
Instructions
Step 1
In urban environments, antenna dimensions and ease of installation are important. For these qualities, an L-shaped antenna is most suitable for you. It consists of a horizontal part and a drop. The length of the horizontal part of a standard L-shaped antenna can be from 20 to 40 meters. The longer the antenna, the higher the overall sensitivity of the receiving device will be.
Step 2
Choose a place to mount the horizontal part of the antenna. You need to suspend the antenna as high as possible above the ground. The horizontal part can be fixed to structures on the roofs of buildings, on specially installed poles and masts, on tall trees. The main thing is to avoid the proximity of current-carrying wires and electrical installations. The wire of the horizontal part of the antenna is not attached directly to the supports, but with an insulator using a chain. As insulators, you can use both special antenna and ceramic or glass rollers for external wiring, as well as fiberglass plates with holes drilled in them.
Step 3
You can make the antenna from a single-core copper, bronze or aluminum wire, as well as from a special multi-core antenna cable. Moreover, the copper wire must be taken with a cross section of at least 2 mm, bronze - from 1.5 mm and more, the aluminum wire must have a diameter of at least 4.5 mm. Lowering the antenna is usually done from the same wire as the horizontal part. If you want to make the antenna longer, the wire cross-section will need to be increased.
Step 4
If you want to suspend the antenna on the roof of a high-rise building, first mount it on the ground, immediately attaching the suspension insulators and measuring the drop. Lower the cable from the roof of the building, fix on it the end of the antenna farthest from the lowering, lift it to the roof and fix it. Next, raise the antenna drop in the same way. Insert a plastic tube into the hole in the window frame, pass the drop wire into the tube and wind it tightly around the nearest central heating pipe (the pipe in this place must first be cleaned of paint). This will protect you from static electricity damage during further work.
Step 5
Now, in the same way, lift and fix the other end of the antenna. The antenna can be fastened with knitting or bolted connections. Make sure the drop does not touch the edges of the roof or any other structure. For these purposes, you can make spacer poles with an insulator (for example, a roller) at the end. In working condition, the drop wire must be connected to the antenna socket of the receiver.
Step 6
To work with an external antenna, you will need to install ESD and lightning protection. As an electrostatic protection, you can use a neon lamp (for example, from a starter for fluorescent lamps) connected between the antenna and ground. For lightning protection, use a simple switch to close the drop wire to ground. Do not use an external antenna during thunderstorms. When not in operation, the antenna drop must always be grounded.
Step 7
Mount the drop and lightning protection switch on a plexiglass or fiberglass plate. In the absence of a specially made grounding, you can use a central heating network pipe as it, having previously stripped it of paint and soldered a thick copper wire to it.
