Module 3 - Radio Equipment Basics
- Reading Assignment
- The Basic Radio System
- Buying Your First Radio
- Base Stations
- Accessories - Station
- Hand Held Radios
- Quiz 3
- Recommended Reading
Read Chapter 2, Pages 2-11 to 2-13 in your text before you continue.
If you have questions after reading the assignment, consult the recommended reading.
I have included additional information that I think you would like to know about equipment that is beyond just passing the test. This will help you in getting your equipment & enjoying the hobby. The quiz questions will let you know what you need to pass the exam.
Obtaining your Technician Ham License does not "make" you an amateur radio operator. It's the beginning of a long but fun journey. Just like your first driver's license, after obtain your amateur license, you need to keep learning. It really helps you enjoy your new hobby even more.
The Basic Radio System
As you might recall from the beginning of Module 2, the basic radio transceiver consists of a receiver & a transmitter, hence transceiver, a power supply & an antenna switch or T/R switch. Many also need a power supply. The radio is then connected to an antenna so it can both transmit and receive signals.
In this module we will cover different type of radio equipment including base stations, mobiles & hand-held portables. Equipment has evolved from earlier days and become smaller and more sophisticated. A transceiver that is multi-band (different frequency bands) and multi-mode (many modes or types of modulation)like SSB, AM, CW, Data, FM and more.) Lets take a look at some of the equipment that is available.
Buying Your First Radio
I strongly encourage you to attend ham radio club meetings in your local area. Our club Sierra Foothills Amateur Radio Club has many members that would be happy to help you. You will be exposed to different views on what is the best brand and models to obtain. This way you will get to see and probably touch various pieces of equipment. Most of us are very proud of our 'rigs' as ham equipment is often called.
Here are some links to other hams that will express their views on what you should look for.
The first is the ARRL. The ARRL, as you know, is the non-profit organization that is the Ham Radio advocate in many areas. They are a great source for information in many areas. ARRL - Buying your first Radio
Another good Ham information source is eham.net. Visit their site often, too. Buying your First Radio - eham.net
One more reference on Buy a First Radio - Ham Universe
The base station radio is simply a radio that is used in a fixed location. What further defines a base station is that it typical has a physical fixed antenna. We will be covering antennas in a later module. Some base units have a power supply built into the radio.
The power supply converts common household voltage (typically 120 Volts AC) into the voltages that the radio needs to power its circuits. However, many base units no longer have a power supply built into them. Rather, they operate on 13.8VDC (commonly referred to as 12 volts) just like most mobile radios.
Most of us don't have 13.8 volts dc readily available in their home, so the power supply now is an external device that converts 120 VAC into 13.8 VDC, to power the radio.
Now a base station radio is generally defined by larger size and extra functions. In other words a piece of equipment that is too large to conveniently mount in a car or pickup.
Shown are two popular base stations. Do not be intimidated by all the controls, knobs, switches and screens. Believe it or not, by the time you are ready for a multi-mode hf rig, you will become very familiar with their function and uses.
Accessories - Station
External Speakers - Most of the base and mobiles have an internal speaker. However, they are usually small and may not be conveniently located on the radio. Since there are many controls on the front of the radio there is not room for a speaker.
There are many external speakers that will give superior audio quality. Some have filters that can be switched in and out to enhance either highs or lows and make it easier to understand what is being said.
Sometimes there are distracting noises or maybe you don't want to bother others with the audio coming out of your transceiver. The answer to both of these problems is a quality headphone set.
It is much easier to discern what is being said when using headphones.
Another assessor most hams use at the base is a quality microphone. You can obtain microphones with superior quality for reasonable prices. The base mikes can really enhance your 'on-the-air' voice quality.
If you are interested in CW (Morse Code) you most certainly need a key, or maybe even a 'bug'. The basic key will allow you to send code by varying how long you hold down the key to send either a dit or a dah. The semi-automatic key or bug also pictured will continue to send dits as long as you hold it to one side. The dahs are sent individually by pressing the key the opposite direction from the dits. An Elecronic keyer will send continuiously send dits or dahs depending on which side is pressed.
While Morse code is no longer required to obtain a license, it is still a large part of the hobby for many hams.
A Straight Key, a Bug, an Electronic Keyer or a Computer Keyboard all can be used to transmit CW in the amateur bands.
A computer is more and more becoming a necessary accessory for Hams. A computer can control your base station and show all your options on one screen, rather than in imbedded menus on the radio itself.
The computer is mandatory for running digital programs such as PSK, RTTY, Slow-Scan TV, Fast-Scan TV and more. You can also automatically look up call-sign information on the internet, auto-point your directional antenna and determine what parts of the bands are 'open' (good conditions)to make contacts.
You can also use the computer to send e-mail via computer programs tied to your transceiver when you are out in the sticks or out to sea!
The camera is used to capture the video needed for Ham-TV.
There are other accessories that allow you to operate your station more efficiently.
The antenna rotor and control box allow you to rotate your directional antenna (beam) and point it towards the area you want. By using a beam antenna you greatly enhance signals comming from a particular direction and attneuate those comming from other directins.
A power amplifer will take the output from your transceiver, usually a maximum of 100 watts, and increase it to 300 watts, 500 watts or even to the legal limit for hams. More power usually increased your signal strength at the far receiving end.
An antenna tuner will match the impedance of your radio and feed line to your radio. Since you can operate on a wide range of frequencies, your antenna may not be a perfect match. The antenna tuner helps solve this problem. Remember we mentioned reflected power in the last module, and it will be covered in more detail in a later module.
The antenna tuner pictured also has a built in SWR meter. These can be purchased separately from the tuner also. The SWR meter allow you to see if the impedances of your antenna and transmitter match. If they don't match, it shows you the ratio of how much is forward power (radiated by the antenna) to how much is reflected back and dissipated as heat.
This particular model shows both directions at the same time, so you can see the interaction of tuning on both forward and reflected power at the same time. This aids greatly aids in tuning.
The other device in this picture is a low pass filter. It is inserted into the feed line between your transmitter and antenna. The filter is useful in greatly attenuating any unwanted weak signal on frequencies other than than one which you want to transmit.
An example of this would be interference to your neighbors TV reception.
Hand Held Radios
A hand-held radio or HT or portable or what ever you want to call it is a great starter radio. You can pick one up for under a hundred bucks and have a great time with it.
There are some who would discourage you buying a HT for your first radio, but if your budget is tight, it can be a good starter radio.
The portable has limited range because of the 'rubber ducky' antenna, however, it is easy to attach an outside antenna or a mobile antenna when you are in the mobile.
A spare battery or ac power supply take care of the limited time of operation because of the battery giving out. It takes very little power to receive and even less to monitor the frequency. If you put the radio in the charger cradle while you are not transmitting you will easily get a long operation time.
The radio has the same specifications as a base or mobile, without the bells and whistles. The only thing they usually have limited power output (5 watts).
However, this may not limit you all that much as the next section will make apparent.
your hand-held carefully to make sure it has the frequency
range you need and is easy to program.
Repeaters are automated stations located at high places that receive and then retransmit your signal â€“ simultaneously. They dramatically improve your range especially your HT or hand held. The basic components of a repeater are the same as your station: receiver, transmitter, antenna and power supply. But, repeaters are transmitting and receiving at the same time using the same antenna.
This requires very high quality and specialized filters to prevent the transmitted signal from overpowering the receiver. This specialized filter is called a duplexer.
It filters only allow the transmit frequency of the transmitter to make it to the antenna. Any unwanted signal on the receive frequency are greatly attenuated. Likewise the receiver filter only allows the desired frequency to get through from the antenna none of the transmit signal.
Also the transmit and receive frequencies are not the same. On VHF they are separated by 600 KHz & on UHF they are separated by 5 Mhz. This is called the repeater offset.
Ok all fine and good, but so what good do they do? Well what they do is greatly extend our range. VHF bands that Technicians use are pretty much line of site. The signals at these frequencies don't bend much, only a little.
Now how about if we put a repeater on a mountain top and receive signals on one frequency, then simultaneously retransmit them on a different frequency. Well, if our transceiver transmits on the repeater receive frequency then it will re-broadcast the signal. Now if everyone else listens on the repeater transmit frequency then they will all hear the signal.
Bottom line if you can talk to the repeater, you can talk to anyone else who can talk to the repeater even if we are not in a position to be able to talk directly with one another.
You can find local repeaters by looking them up in a repeater directory or on the internet. Your receive frequency is listed and next to it is a '+' or a '-' this tells you what direction the offset is. They will also usually list a tone frequency 162.4, for example. This is a tone coded squelch frequency (CTCSS for those of you looking for answers to the test). You transmit this sub-audible tone at a very low level in addition to your voice information. The tone unlocks the receiver so the repeater can hear the signal and then retransmit it. The transmit and receive tones are not always the same. If the tone is not present you will not 'get into the repeater' and no one will hear you.
You will receive instant feedback to your answers and
you will be able to see how you did on the quiz overall.
Also you will be able to view a detailed summary of the
All answers, whether right or wrong, will be referenced back to your text so you can review and correct any wrong answers.
Tips on how to remember the correct answer are included.
You can take the quiz as often as you wish.
No one but you will see the quiz results.
Hope this module was fun for you. It introduced you to some equipment and gave you some information on what is available. It also introduced the repeater, which makes it all work so well. Now you can start dreaming of all the different equipment you want to get. You'll never be hard to buy for at gift times again. Take the time to review the material in your manual.
View the complete Technician Question Pool in Chapter 11 of your Ham Radio License Manual.
Review the complete Technician Question Pool with Hints to help you to remember the answers for the test available by clicking the last item on the left hand select menu.
Read, Read, Read. Many books are available from the ARRL. Many articles are also readily available on the internet.
There are several videos on You Tube. Do a search on Amateur Radio, Ham Radio Technician License, variations of these or on the exact subject matter in which you are interested.
Review the Term Glossary in Chapter 10 of your Ham Radio License Manual
Practice Exams are available at www.arrl.org/exam-practice and there are links to many other test practice sites also.