Radio Equipment

1. Radio Equipment ARRL Book Chapter 3, section 3.1

2. Basic Radio Station • Source of Power • Implied a way of connecting it • A Transciever (combination transmitter to send and receiver to receive) • Probably have a microphone to send voice • May have other sending equipment such as a computer or Morse code telegraph key • An Antenna to radiate the signal • Implied a connection from transceiver to the antenna • Coax cable is the common choice

3. Talking on a Radio • Sending radio codes information into radio waves on a specific frequency • Receiving radio on the same frequency reads the radio waves and decodes the information • Transmitting and Receiving on the Same Frequency is called Simplex Operation(T5C08) • Radios can only communicate if they are coding and decoding information on a common frequency • Radios select the frequency using a VFO knob or keypad on a microphone(T5B03) • Usually turning the largest knob on the radio makes the frequency change up and down • Most knobs have a distinct click feel when turned. The size of the jump in frequency with each click is called the step (most radios the standard step is 5000 hertz or 0.005 megahertz) • Most radios have a menu option called step that lets you set the size of the frequency change with each click(T5B10) • RIT refers to this receiver incremental tuning (T5B09)

4. The Problem of the VFO Knob(by the way VFO stands for Variable frequency oscillator – it allows the radio to send and receive on different frequencies) • The 2 meter amateur band is from 144 to 148 megahertz. • If you go in steps of 5000 hertz at a time it would take 800 steps to go from end to end (that gets pretty old if your changing frequencies) • Many radios have an up and down button on the microphone. These button tune frequencies up or down one step at a time or choose a “a computer memory”(T5B07) • Some radios have up and down buttons on the radio itself instead of knobs • Some radios have keypads on the microphone or radio and you type in the frequency • This can be a lot quicker than turning a knob round and round • It’s a nice feature – but most radios don’t have it • Chris Pixton’s favorite Icom V8000 does have the feature. • I use Azden 5000 in my car that key pads on the radio.

5. Radio Memory Features • One way to get quick access to a commonly used frequency is to store it in a memory channel (T5B05) • Most of us our pretty use to our phone and calculators have memory space to store things • Probably want your radio to have memories • 1990s vintage radios may have about 10 to 20 memories • New radios from last 5 years have 200 to 500 memories • President Shane envisions having 4 sub-areas of the Stake – Sikestone/Popular Bluff, Jackson/ Cape, Farmington area, Carbondale/Steelville • In Carbondale/Steelville we have coordinated so that we store the same frequencies in the same memories – we have 22 memories • If we say channel 1 we all go to memory 1 which is 144.37 megahertz or the Ward primary frequency • A Typical radio memory channel can store a transmit frequency, a receive frequency, a CTCSS frequency, and a power output level (T5B02)

6. The Problem of Noise • Always stray radio signals or noise – lighting is a big cause • See fuzzy picture on a TV or hear static • Get the same static on a radio • You can use that noise to help you set the volume on your radio but probably don’t want to hear it all the time. • Most radios have a squelch knob that block out sounds when you are not receiving a message (T5B04) • Trick is that most noise signal are weak – a squelch just blocks all signals that are weaker than a certain amount • Warning – setting squelch too high can block weak messages to • I was having trouble getting a message from Farmington – my wife had turned up the squelch • After you set the volume you usually turn the squelch up just enough to make the noise disappear

7. Repeaters • Repeaters increase your range. They are usually on very high ground – they take your signal and repeat it • We have a big Stake when we try to do a net across the whole stake we use repeaters (usually Alto Pass 146.85 megahertz) • A repeater would talk over itself if it tried to receive and resend on the same frequency • Repeaters receive signals on one frequency and send them on another frequency (T5C07) • We often call talking on a repeater “Duplex” (because it has a separate send and receive frequency)

8. Duplex • Most important information to know before using a repeater is the input and output frequencies(T5C03) • Can be interesting because when you squeeze the push to transmit button on the microphone you will see the frequency display change • Spacing between send and receive frequencies is called an “offset” • There are standard spacings • The Most Common 2 meter repeater offset is 0.6 megahertz (600 kilohertz) (T5C05) • The Most Common 70 centimeter repeater offset is 5 megahertz (T5C06)

9. More on Repeaters • Range of VHF signals varies with weather • Sometimes more one repeater on a frequency • Alto Pass, Suburban St. Louis, and Peoria all on same frequency • Repeaters use CTCSS tones to tell which repeater was intended • This is a sub audible tone than has to be sent with the signal to tell a repeater the message if for it • Many 1980s vintage radios do not have CTCSS tones, can’t use them on many repeaters (may be a back-up radio, but probably not primary in this area where we do use repeaters some) • We try to use simplex because never know when a repeater will be down • Auto offset – Since repeaters function in certain frequency ranges some newer radios recognize repeater frequency and put in offset automatically • Older ones have to separately set transmit and receive frequency • Can be easier if a repeater has a non-standard offset, but nothing around here does.

10. Simple and Fancy • Older radios have buttons and dials that perform basic radio functions • Turn on the CTCSS tone by pushing the Tone button • Newer radios have numerous special features – they are made to be small so can’t put buttons all over them • They use menus activated by pushing the right series of buttons • Most radios have an F button that is used to pick multiple functions for one button (T5B11)

11. Which is Best? • If buying a newer radio you already know it will be fancy • Used radio – who knows could be old or a bargain new. • Most radios will have features don’t use every day (memories make setting offsets, CTCSS and frequency unnecessary) • Hard to remember everything • Suggestions on remembering • Make a copy of your instructions (on paper to store with your radio and stash the original) • I have a condensed instruction sheet for basic functions that I created • Consider buying the same radio as a friend so that you can compare notes • Chris Pixton likes the Icom V8000

12. Message Security • Church has emphasized keeping things simple • This has favored voice on common VHF radios • Down-side, privacy, scanners routinely listen to amateur radio. • Can be great getting help but if you identify the location of a problem it can be directions for looters • Church suggestions • Consider whether sensitive person information needs to be transmitted on non-secure systems • Standard maps, (the M family at E4 on page 51) • Its not code – E4 is a map coordinate and page 51 is the 51rst page in a map book • But not everyone has the map book • Details and procedures may come down to a local plan.

13. List Handling • In addition to security, one limit of voice it the list. • Describing a map or image can be almost impossible • With list one word may sound like another or you can forget something • People are trying to read a list on one side and recreate it on another • One solution is digital handling • Can send e-mails, images, and lists digitally • Digital transmissions require decoding – not everybody with a radio shack scanner can do that

14. Digital Modes • Computer talks into the radio instead of your voice • A microphone is not needed for packet radio (T5A09) • For Packet Radio to connect between a computer and a radio you need a terminal node controller (T5A08) • Some newer radios are already packet ready and have node controllers built in • A computer can make data ready to send over a radio with a sound card (T5A10) • A radio can also be linked to an internet line – such a radio station is called a gateway(T6A03) • There are already networks of computers that are part of gateway systems • Privately maintained just like repeaters • Can be used for voice – I talked to a guy in Arizona on 2 meters, Lee talked to a guy from England

15. What Does the Church Do With Digital • The Church has considered adopting digital guidelines • Right now much more emphasis on people getting emergency plans and capabilities • A back-up communication system cannot depend on the system it is intended to replace • If phones are out many internet lines will be out too • Of course if you can radio to a gateway out of the damage area you may be able to use internet lines • Packet does not depend on gateways to enable computer communication • “Paulism” concern – power for a computer is much worse than a radio • Laptop battery only good for about 2 hours • Back-up generators (except premium Honda’s) often do not give clean electric power sine waves – computers are much more sensitive to “dirty power” than battery chargers (where do you charge your laptop battery?)

16. Trouble Shooting Ideas • Feedback – If your microphone is located too close to the speaker you will get audio feedback (T5A03) • Most of us have already had the unpleasant experience of getting our ears blown out with a feedback squeal in a sound system in an auditorium • Radio Frequency energy gets into microphone circuit it can cause Single Side Band (SSB) signals to be garbled and break-up (T5D11) • Another Garbler • What happens if you try to play music too loud for the speakers and amplifier circuits on your stereo • In radio the microphone signal goes through a pre-amplifier before going to the final amplifier on the radio • The setting of pre-amp is called the gain on the microphone • Some radios may seem to send real soft signals – have the gain on the mike checked – it may be too low • If the gain on the microphone is set too high the signal will become distorted and unreadable (T5B01) • When you hold the microphone hold it to the side of your mouth and talk across it • This will prevent breathy pops from hyperventilating into the microphone • May need to adjust how close to your mouth depending on how the gain is set • If gain is too low screaming into the mike will not make your signal louder

17. More Noise and Interference • When radio is in the car the generators a boosters for spark plug voltage can produce ignition noise – can make it hard to hear message • One reason Chris Pixton hates my cigarette lighter hook-ups – lighter wiring picks up ignition noise • Very likely to be a problem on HF, maybe side band (I use FM on VHF) • If you are getting ignition noise some radios have a noise blanker that can be turned on to suppress it (T5B06)

18. Dumby Loads Don’t Mean Your Stupid • Sometimes you need to trouble shoot or adjust a radio • If you transmit before things are set it will send out an annoying signal (this is especially an issue on HF) • The Purpose of a Dumby Load is to avoid sending out signals while doing tests on a radio(T9A05) • Dumby load acts just like an antenna but it has no radiating elements • Suggestion on special equipment items • SWR meters dumby loads frequency counters • Don’t everyone go and buy – a few people can buy, share and help others • I have most basic radio diagnostic toys