Operating a HAM radio is very basic and although the levels of knowledge of HAM radio operation is unlimited; here are some of the basics that will get you going.
1. Bands and Frequencies
Amateur Radio (HAM) uses bands and frequencies in the following ranges:
VHF Band:136.000 MHz through 174.000 MHz (Rx/Tx)
UHF Band:400.000MHz through 480.000 MHz (Rx/Tx)
- Bands basically just identify separate radio frequency 'ranges'.
- Modern HAM radio's are usually 'Dual Band' meaning they are designed to transmit and receive on both frequency ranges.
- Usually you just select the frequency range you want to use (Band) and input the exact frequency you want to listen on using the keypad on the radio.
- Modern radios allow you to save a hundred or more preset frequencies (channels) which you can access in 'Channel' mode.
- Modern radios allow you to 'scan' either the entire frequency range or scan the preset 'Channels' range.
The following radio types use frequencies within the Amateur Radio (HAM) spectrum:
• FRS (Family Radio Service) - Common walkie talkie 0.5 watt max - No License Required
• GMRS (General Mobile Radio Service) - Long range walkie talkies 5 watt max - FCC License Required
• MURS (Multi-Use Radio Service) - Marine radios 2.0 watt max - No License Required
• Police, Fire & Rescue, City Services (Usually in the UHF range 400.000 and above)
• HAM Frequencies DO NOT include CB (Citizens Band) radio frequencies.
• HAM radio's can be set to the same channels that FRS/GMRS/MURS use and those radios can work with HAM radios.
• Most 'Mobile' HAM radios broadcast at 5 watts max (limited by FCC), which is higher and broadcasts further than most other radio types.
You will need to pay attention to which frequencies you broadcast on and stay away from frequencies used by local City, County and State departments. We suggest you do some homework and find out which frequencies are in use in your *local area*. Broadcasting on a government channel can result in fines. However during WROL, of course use whatever predetermined frequencies work for your group.
Many Amateur Radio (HAM) operators use software to program hundreds of channels into the memory of their radios. One free version is called CHIRP located at http://chirp.danplanet.com which can be used, with an optional USB to radio cable, to program the Baofeng UV-5R+ and Wouxun KG-UV2D and many other manufacturers and models.
2. Frequency Step
The frequency 'Step' is basically the amount of space between frequencies. Modern radios allow the frequency step to be set as low as 2.5kHz to as high as 50kHz. We recommend that you set it to 2.5kHz. This setting basically only affects the granularity of the frequency you can set on the radio and the granularity of the frequencies scanned when scanning for traffic on frequencies in scan mode.
Examples:
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If the radio's frequency step is set to 25kHz and you try to put in frequency 150.011 the radio would round down and set the freq to 150.000.
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If the radio's frequency step is set to 2.5kHz and you try to set it to 150.011 the radio would round down and set the freq to 150.010.
- If the radio's frequency step is set to 25kHz if you enable 'Scanning Mode' to scan for traffic, it will skip from freq 150.000 to 150.025 to 150.050 etc.
- If the radio's frequency step is set to 2.5kHz and 'Scanning Mode' is enabled, it will skip from 150.000 to 150.002 to 150.005 etc
3. Transmitting (Tx) and Receiving (Rx)
Radios 'Listen' on the 'Receiving' (Rx) frequency and 'Talk/Transmit' on the 'Transmitting' (Tx) frequency.
Those frequencies *can be different* from one another, usually only when talking to a Repeater station.
There are two modes of transmitting and receiving:
• Simplex - To receive and transmit on the same frequency. - (Person to Person communication)
• Duplex - To receive on one frequency and transmit on another frequency. - (Person to Repeater communication)
- Most modern radio's have the ability to use Simplex and Duplex modes.
- Duplex mode is usually only used when transmitting to a 'Repeater' station which will re-broadcast your transmission.
- Duplex mode is not a 'setting' but is controlled by the 'Frequency Shift' and 'Frequency Offset' set on the radio for the frequency in use.
- Duplex mode can be used on different Bands so that Dual Band radios can hear on one band and transmit on another at the same time.
- Most radios also have a 'High' and 'Low' Transmit power setting which controls how much power is used when transmitting. (Higher power, longer range)
3. Frequency Offset and Frequency Shift
Frequency Offset - controls the frequency that the radio 'Transmits' on. Frequency Offset is usually only used with 'Duplex Mode' when transmitting to a repeater station. For example; if a Repeater station is Transmitting on 147.000 with an Offset of -0.600; it means that the repeater has a negative offset of 0.600kHz and it is *Listening* for radio transmissions on frequency 146.400 which is 0.600kHz below its Transmission frequency. When it hears a transmission on frequency 146.400, it will re-transmit them on 147.000.
Frequency Shift - specifies to 'Transmit' to the Repeater above (+) or below (-) the frequency the Repeater is broadcasting on using the value specified in the 'Frequency Offset' setting.
Frequency Shift setting can be set to one of the following:
"+" - Transmit above the Receive frequency currently set on *your* radio.
"-" - Transmit below the Receive frequency currently set on *your* radio.
"split" - Receive on UHF and Transmit on VHF or (vice versa depending on the transmit freq)
"off" - Transmit and Receive on the same channel (Simplex Mode)
The most common Offset value is 00.600. (either + or - ) when transmitting to a repeater.
For person to person communications (Simplex Mode) set the Frequency Shift to 'Off' and the Offset to 00.000.
4. Squelch
Squelch is just a feature that blocks you from hearing static. It allows you to set minimum level of signal quality required before your radio plays it to you through its speaker (or headphone). Set the squelch level depending on the amount of interference and static in your area and the distance or difficulty hearing other radio's you're trying to listen to transmissions from. Most radio's have a button that disables squelch while its held down in case you want to hear a transmission from a source that is difficult to hear.
Its recommended to set your squelch to the lowest level that you find tolerable, otherwise your radio may block poor quality, but important transmissions.
5. Security and Squelch Modes CTCSS and DCS
Continuous Tone-Coded Squelch System (CTCSS) and Digital-Coded Squelch (DCS) are just sub-audible tones transmitted along with a voice transmission to activate or deactivate the squelch feature on a radio *receiving* the transmission. They are sometimes referred to as 'Privacy Channels' but they provide *neither privacy nor security*. Radios that don't support either feature will hear everything you transmit. Basically the sub-audible tones activate the squelch feature on the radio *Receiving* the transmission (*your* radio) to block out the incoming transmission unless the sub-audible tones the 'Transmitter' sent match the CTCSS or DCS settings on the 'Receiving' radio. If the CTCSS/DCS settings match on both radios, the squelch feature on the *Receiving* radio will temporarily disable squelch and it will play the transmission through its speakers.
• CTCSS and DCS is NOT A SECURITY FEATURE or a method to secure or encrypt transmitted messages.
The only way your transmissions will be 'Secure' is if you either talk in code (for whatever thats worth), use radios that encrypt transmissions and or skip channels every millisecond (like military SINGARS radios)
6. Repeaters
Repeaters are privately owned HAM radios, listening on a specific frequency, usually installed on mountain tops powered by solar or wind or plugged into the grid.
Repeating stations (Repeaters) receive on the 'Receive (Rx)' frequency and re-transmit (re-broadcast) transmissions it hears on the 'Transmit (Tx) frequency.
You listen to repeaters by tuning into their 'Transmit' (Tx) frequency.
You talk to repeaters by transmitting a signal to their 'Receive' (Rx) frequency.
This is usually accomplished by setting the Receive (Rx) frequency *on your radio* to the repeaters Transmitting frequency (so you can hear it when it transmits) and then setting the 'Frequency Offset' and 'Frequency Shift' *on your radio* according to the settings the repeater requires. (Usually those settings are documented online by the owner of the repeater). This will cause your radio to Transmit to the repeaters 'Receive' (Rx) frequency when you try to talk to it and it will re-transmit your transmission on its Transmit (Tx) frequency. This is called Duplex Mode.
• Most repeaters use Duplex mode with a + or - 0.600 offset.
• Some repeaters require you to transmit a "PL" tone (CTCSS tone or DCS tone) to trigger them to re-broadcast your transmission.
7. Antennas
The antenna is just as if not more important than the radio itself. Most radio's come with a stubby antenna which has a coil of fine wire (2 meters worth) wound around a center pole. These antennas are compact, but they limit both transmit and receive capabilities.
We recommend that you replace stubby antennas with 1/4 wave whip antennas which will improve both the radios transmit and receive capability.
Even though mobile/handheld HAM radios are small, the antenna's are modular which means you can attach large/full size J Pole (straight wire) and Yaggi ( tree branch looking) type antennas to them using radio cable. Its common practice to do this with small mobile radios and talk to satellite HAM repeaters in space (for 10 minutes a day as they fly over) allowing you to talk to people all over the U.S. and South America.