How To Hook Up A Radio

These instructions are for the uninformed or beginner as to how to connect a radio or transceiver to an antenna and power supply. Many knowledgeable people just assume everybody knows how you can do this.

First you must understand there are at least two requirements: An antenna sufficient for the frequency or band you wish to listen, and a power source.

The power source can be internal batteries, external battery or power supply, AC power cord, or external wall adapter sometimes referred to as a "wall wart". Most radios operate off of 6 volts or 12 volts. In purchasing a new radio you should have received an appropriate power cable or adapter. More expensive radios have just an AC cable that plugs into the back of the radio as shown below.

Powerful transceivers most times have two heavy duty terminals, usually red and black so you can connect it to a 12 volt power supply or battery, or a special connector with heavy red and black wire pigtails. The black special connector is shown below.

Some cables are wired directly to the back and cannot be removed. More low cost radios have a small circular connector called a coaxial power connector. Care should be taken when replacing the power source or wall wart that the center pin is either plus or minus and is matched up. A little picture on the wall transformer and the radio should show one of the following:

Beware that some substitute transformers might be AC output and are not usable in DC applications. In the example below, the jack on the right's polarity is center negative.

If you plug a source in with the polarity reversed you will very likely destroy your radio.

Radios for listening, WiFi routers and switches, battery chargers, CD players, and some laptops use this type of connector.

Radios that also transmit and receive are called transceivers. They may use a larger connector and a larger power supply depending upon the power output. These transceivers are Amateur Radio, CB, or Business Band, such as GMRS or Public Service (police/fire).

It is also possible to find a cigarette lighter adapter to provide power while the radio is being used in your car. Make sure you consult someone with experience to verify the correct polarity and voltage since car voltages can reach 15 volts.


Some radios have an internal telescoping antenna or internal loop antenna.

Other radios for Short Wave listening may have a set of terminals or a jack that allow you to connect up an external antenna to pull in distant radio stations.

In some instances you can just hook up one or two wires to the terminals and extend them out and away from your radio a few feet. The problem is that if these antenna wires are inside your house, your house may shield the antenna and you won't be able to hear weak signals, and you may pick up noise from TV's, appliances, and wall warts that generate unwanted noise.

To prevent unwanted interference from electrical sources in your house, you will want to connect a cable called coax which has an internal wire covered with white insulation and an outside braid covered with black insulation. This will get your signal into your radio without interference. Below is an example of RG8X.

Below shows how noise from electronics in a house is minimized by running coax from the radio to an antenna outside so you can hear weaker signals.

Better transceivers have an SO-239 coax connector on the back of the radio that allows you to run a long length of coax, say 100 feet or more to the antenna, well away from your house and any offending interference or a higher elevation for better coverage.

Coax connectors come in many styles but the most common are SO-239 and BNC.

UHF radios may also have a more professional connector that is called an "N" connector.

 

Many newer cheap walkie talkies use a SMA, or a Reverse SMA connector like the Baofeng brand shown below. The R-SMA or Reverse SMA has a male pin as the arrow shows rather than a female socket. If you need to hook this radio up to an antenna via a coax, you can purchase an adapter to convert the R-SMA to a BNC connector.

 

Coax used in most applications is RG8, RG8X or RG58.

Better coax is much more expensive and could be LMR200, LMR400, RG213, LDF4-50. These are used in professional installations. You can purchase connectors and prewired cables off ebay for about $0.60 a foot with connectors or you can purchase bulk wire and connectors off ebay and make your own custom lengths. You can also order cables and connectors here.

The next hurdle is providing a suitable antenna for your given frequency or band whether it's MW, HF and HAM, CB, VHF, or UHF Ham and GMRS/Business band.

A band is an area of the radio spectrum assigned for a specific purpose. The HF band is from 2 to 25 mhz or 80 thru 10 meters, the VHF band is 30 mhz thru 300 mhz or 10 thru 2 meters, and the UHF band is 300 mhz to 3000 mhz band.

 

For short wave broadcast listening or Amateur Radio listening and transmitting from 2 mhz to 30 mhz, you can use a low cost dipole wire stretched out clear of any obstacles.

This single band dipole above is for one band only. However for listening it can be used across the whole band with somewhat reduced effectiveness. It is the cheapest type of antenna and can be built from scratch for less than $30. It is possible to install "traps" to allow multi band use. Traps are parallel tuned circuits that electrically stop the frequency to make the radio see different electrical resonant points (lengths). Resonance of the antenna allows better transfer of power to the atmosphere. 

For multi band dipole configurations, do a web search on the type of antennas below:

 

 

 

 

 

If you are seriously into receiving and transmitting and want a much better antenna you may want a multi-band omni directional vertical antenna but be prepared to pay over $300 for it. Such antennas are the Cushcraft 14AVQ or Gap Challenger DX6 or Hustler. These antennas are mounted on the ground.

23ft tall

Still another type of popular antenna is an EFHW. End Fed Half Wave. It uses a 49:1 unun to match the cable to the antenna wire. A unun is a special transformer which takes the unbalanced signal from the cable and converts it to an unbalanced line to the antenna. For more information Google "EFHW antenna". Some dipoles use a balun to match the unbalanced coax to a balanced antenna.

 

 

For VHF and UHF Ham and GMRS, you need a good base antenna for your house and should be as high as possible. The Diamond X50 shown below is ideal for this application. It can be mounted on the chimney, tower or mast attached to the house.

5 ft tall

 

Other VHF antennas like the Ringo ARX-2 is ideal for Ham and Public Service.

 

This page Copyright 2021 Rick C. Ver 0.22 Jan 9, 2021