This group covers locating signals, contest operating, grid locators, and systems that link amateur stations over the internet.
Radio direction finding
Radio direction finding (RDF) uses a directional antenna and a receiver to determine the bearing of a signal. Taking bearings from different places lets you locate a source of noise interference, a jammer, or a hidden transmitter in a fox hunt. The same technique is used in hidden transmitter hunts, a popular activity in which the useful tool is a directional antenna. SWR meters and directional wattmeters measure your own equipment, not the direction to a distant signal. Echolocation, Doppler radar and phase locking are not direction-finding methods for this purpose.
Contesting
Contesting means contacting as many stations as possible during a specified period. Good practice is to be efficient: send only the minimum information needed, your call sign and the contest exchange. Do not shorten your call sign, since you must identify properly; do not work the same station repeatedly; and do not add extra words that slow the exchange. Other operating activities have different purposes: nets pass traffic or check in members, and simulated emergency exercises practice emergency communication.
Grid locators
A grid locator is a letter-number designator assigned to a geographic location, such as the Maidenhead system. VHF and UHF contesters and satellite operators exchange grid squares to report where they are. It is not an instrument or an antenna direction.
Internet linking
VoIP (Voice over Internet Protocol) delivers voice communications over the internet using digital techniques. Several amateur systems use it to link stations and repeaters:
IRLP (Internet Radio Linking Project) connects amateur systems, such as repeaters, via the internet. You access an IRLP node over the air with DTMF (touch-tone) signals, not with passwords or CTCSS tones.
EchoLink lets you connect through a linked repeater from a computer or smartphone, so you can transmit without a radio starting the transmission. Before using it, you must register your call sign and provide proof of license. No training, fee or General Class license is required.
D-STAR and DMR are digital voice systems that normally use a radio to key up.
A gateway is an amateur station that connects other amateur stations to the internet. A repeater retransmits over radio only, a digipeater relays packet data, and a beacon transmits for identification or propagation checks.
Key facts to memorize
Radio direction finding locates noise sources, jammers and hidden transmitters.
A directional antenna is the key item for a hidden transmitter hunt.
Contesting is contacting as many stations as possible in a set period.
Send only the call sign and exchange in a contest.
A grid locator is a letter-number designator for a geographic location.
IRLP is accessed with DTMF signals.
VoIP carries voice over the internet digitally.
EchoLink requires registering your call sign with proof of license.
A gateway connects amateur stations to the internet.
Memory hooks
You “dial” an IRLP node like a phone call, by keying in its number with touch tones (DTMF).
EchoLink: Echo plus your Evidence of license.
Questions in this group (11): answers shown
T8C01
Which of the following methods is used to locate sources of noise interference or jamming?
A. Echolocation
B. Doppler radar
C. Radio direction finding ✓ Correct answer
D. Phase locking
Radio direction finding uses a directional antenna and receiver to find the bearing of a signal, so several bearings can pinpoint a noise source or jammer. Echolocation, Doppler radar and phase locking do not locate interference sources.
T8C02
Which of these items would be useful for a hidden transmitter hunt?
A. Calibrated SWR meter
B. A directional antenna ✓ Correct answer
C. A directional wattmeter
D. All these choices are correct
A directional antenna, such as a Yagi or loop, with a receiver gives the bearing to the hidden transmitter. SWR meters and directional wattmeters measure your own transmitter and feed line, not the direction of a distant signal.
T8C03
What operating activity involves contacting as many stations as possible during a specified period?
A. Simulated emergency exercises
B. Net operations
C. Hidden transmitter hunts
D. Contesting ✓ Correct answer
Contesting is the activity of contacting as many stations as possible in a set period, often for points or multipliers. Simulated emergency exercises, nets and hidden transmitter hunts have different goals.
T8C04
Which of the following is good practice when contacting another station in a contest?
A. Signing only the last two letters of your call if there are many other stations calling
B. Contacting the station twice to be sure that you are in his log
C. Sending only the minimum information needed for proper identification and the contest exchange ✓ Correct answer
D. Adding “Please copy” before your exchange
Good contest practice is to send only the minimum needed: your call sign and the contest exchange. Sending partial calls breaks the identification rules, duplicate contacts waste time, and extras like Please copy slow everyone down.
T8C05
What is a grid locator?
A. A letter-number designator assigned to a geographic location ✓ Correct answer
B. A letter-number designator assigned to an azimuth and elevation
C. An instrument for locating faults in power amplifiers
D. An instrument for radio direction finding
A grid locator, such as the Maidenhead system, is a letter-number designator for a geographic area. VHF/UHF contesters and satellite operators exchange it to show location. It is not an instrument or an azimuth designator.
T8C06
How is over the air access to Internet Radio Linking Project (IRLP) nodes accomplished?
A. By obtaining a password that is sent via voice to the node
B. By using Dual-Tone Multi-Frequency (DTMF) signals ✓ Correct answer
C. By entering the proper internet password
D. By using Continuous Tone-Coded Squelch System (CTCSS) tone codes
IRLP nodes are accessed over the air using DTMF (touch-tone) signals sent from your radio to command the node. CTCSS tones only open a repeater's squelch and are not used to link and control IRLP nodes.
T8C07
What is Voice Over Internet Protocol (VoIP)?
A. A set of rules specifying how to identify your station when linked over the internet to another station
B. A technique employed to “spot” DX stations via the internet
C. A technique for measuring the modulation quality of a transmitter using remote sites monitored via the internet
D. A method of delivering voice communications over the internet using digital techniques ✓ Correct answer
Voice over Internet Protocol (VoIP) is a method of sending voice communications over the internet using digital techniques. Systems like EchoLink and IRLP use it to link amateur stations. It is not an ID rule or a DX spotting method.
T8C08
What is the Internet Radio Linking Project (IRLP)?
A. A technique to connect amateur radio systems, such as repeaters, via the internet ✓ Correct answer
B. A system for providing access to websites via amateur radio
C. A system for informing amateurs in real time of the frequency of active DX stations
D. A technique for measuring signal strength of an amateur transmitter via the internet
The Internet Radio Linking Project (IRLP) connects amateur systems such as repeaters over the internet using VoIP. It is not a website access system, DX spotting service or a measurement technique.
T8C09
Which of the following protocols enables an amateur station to transmit through a repeater without using a radio to initiate the transmission?
A. IRLP
B. D-STAR
C. DMR
D. EchoLink ✓ Correct answer
EchoLink can be run from a computer or smartphone, so you can transmit through a linked repeater without a radio starting the transmission. IRLP, D-STAR and DMR all normally require a radio to key up.
T8C10
What is required before using the EchoLink system?
A. Complete the required EchoLink training
B. Purchase a license to use the EchoLink software
C. Register your call sign and provide proof of license ✓ Correct answer
D. At least a General Class license
Before using EchoLink you must register your call sign and provide proof of license, because only licensed amateurs may use it. No special training, software fee or General Class license is required.
T8C11
What is an amateur radio station that connects other amateur stations to the internet?
A. A gateway ✓ Correct answer
B. A repeater
C. A digipeater
D. A beacon
A gateway is an amateur station that connects other amateur stations to the internet. A repeater only retransmits on radio, a digipeater relays packet data over radio, and a beacon just transmits a signal for identification or propagation checks.