Presentation on theme: "ARRL Book Chapter 3, section 3.1"— Presentation transcript:
1 ARRL Book Chapter 3, section 3.1 Radio EquipmentARRL Book Chapter 3, section 3.1
2 Basic Radio Station Source of Power Implied a way of connecting itA Transciever (combination transmitter to send and receiver to receive)Probably have a microphone to send voiceMay have other sending equipment such as a computer or Morse code telegraph keyAn Antenna to radiate the signalImplied a connection from transceiver to the antennaCoax cable is the common choice
3 Talking on a RadioSending radio codes information into radio waves on a specific frequencyReceiving radio on the same frequency reads the radio waves and decodes the informationTransmitting 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 frequencyRadios 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 downMost 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 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 knobsSome radios have keypads on the microphone or radio and you type in the frequencyThis can be a lot quicker than turning a knob round and roundIt’s a nice feature – but most radios don’t have itChris 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 FeaturesOne 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 thingsProbably want your radio to have memories1990s vintage radios may have about 10 to 20 memoriesNew radios from last 5 years have 200 to 500 memoriesPresident Shane envisions having 4 sub-areas of the Stake – Sikestone/Popular Bluff, Jackson/ Cape, Farmington area, Carbondale/SteelvilleIn Carbondale/Steelville we have coordinated so that we store the same frequencies in the same memories – we have 22 memoriesIf we say channel 1 we all go to memory 1 which is megahertz or the Ward primary frequencyA 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 NoiseAlways stray radio signals or noise – lighting is a big causeSee fuzzy picture on a TV or hear staticGet the same static on a radioYou 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 amountWarning – setting squelch too high can block weak messages toI was having trouble getting a message from Farmington – my wife had turned up the squelchAfter you set the volume you usually turn the squelch up just enough to make the noise disappear
7 RepeatersRepeaters increase your range. They are usually on very high ground – they take your signal and repeat itWe have a big Stake when we try to do a net across the whole stake we use repeaters (usually Alto Pass megahertz)A repeater would talk over itself if it tried to receive and resend on the same frequencyRepeaters 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 DuplexMost 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 changeSpacing between send and receive frequencies is called an “offset”There are standard spacingsThe 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 frequencyAlto Pass, Suburban St. Louis, and Peoria all on same frequencyRepeaters use CTCSS tones to tell which repeater was intendedThis is a sub audible tone than has to be sent with the signal to tell a repeater the message if for itMany 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 downAuto offset – Since repeaters function in certain frequency ranges some newer radios recognize repeater frequency and put in offset automaticallyOlder ones have to separately set transmit and receive frequencyCan be easier if a repeater has a non-standard offset, but nothing around here does.
10 Simple and FancyOlder radios have buttons and dials that perform basic radio functionsTurn on the CTCSS tone by pushing the Tone buttonNewer radios have numerous special features – they are made to be small so can’t put buttons all over themThey use menus activated by pushing the right series of buttonsMost 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 fancyUsed 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 everythingSuggestions on rememberingMake 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 createdConsider buying the same radio as a friend so that you can compare notesChris Pixton likes the Icom V8000
12 Message Security Church has emphasized keeping things simple This has favored voice on common VHF radiosDown-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 lootersChurch suggestionsConsider whether sensitive person information needs to be transmitted on non-secure systemsStandard 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 bookBut not everyone has the map bookDetails 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 impossibleWith list one word may sound like another or you can forget somethingPeople are trying to read a list on one side and recreate it on anotherOne solution is digital handlingCan send s, images, and lists digitallyDigital 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 inA 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 systemsPrivately maintained just like repeatersCan 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 guidelinesRight now much more emphasis on people getting emergency plans and capabilitiesA back-up communication system cannot depend on the system it is intended to replaceIf phones are out many internet lines will be out tooOf course if you can radio to a gateway out of the damage area you may be able to use internet linesPacket does not depend on gateways to enable computer communication“Paulism” concern – power for a computer is much worse than a radioLaptop battery only good for about 2 hoursBack-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 auditoriumRadio Frequency energy gets into microphone circuit it can cause Single Side Band (SSB) signals to be garbled and break-up (T5D11)Another GarblerWhat happens if you try to play music too loud for the speakers and amplifier circuits on your stereoIn radio the microphone signal goes through a pre-amplifier before going to the final amplifier on the radioThe setting of pre-amp is called the gain on the microphoneSome radios may seem to send real soft signals – have the gain on the mike checked – it may be too lowIf 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 itThis will prevent breathy pops from hyperventilating into the microphoneMay need to adjust how close to your mouth depending on how the gain is setIf 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 messageOne reason Chris Pixton hates my cigarette lighter hook-ups – lighter wiring picks up ignition noiseVery 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 radioIf 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 elementsSuggestion on special equipment itemsSWR meters dumby loads frequency countersDon’t everyone go and buy – a few people can buy, share and help othersI have most basic radio diagnostic toys