Chapter 6 – Good Operating Practices

• Operating Skill • SSB Voice Operating • Operating CW • Tuning Up • Amateur Radio Internet Gateways • Bandwidth • Spurious Signals • Signal Purity • Interference with Other Services T6-1

Operating Skill

• Band plans are voluntary agreements between operators about how to use the frequencies of an particular amateur band.

– Band plans are available at www.arrl.org.

• First rule of good operating is to always

listen

before you transmit.

• Another good rule is to talk during a contact (QSO) as you would during a face-to-face conversation.

T6-2

144.0

In

Band Plan – 2 meters

145.0

Out CW SSB, Weak Signal

Frequency

144.00-144.05

144.05-144.10

144.10-144.20

144.200

144.20-144.275

144.275-144.300

144.30-144.50

144.50-144.60

144.60-144.90

144.90-145.10

145.10-145.20

Usage

EME (CW) General CW EME & SSB National SSB Calling SSB Operations Beacons OSCAR Subband Linear Translator Inputs Repeater Inputs Weak Signal SSB Linear Translator Outputs

146.0

147.0

148.0

In Out Out In Repeater FM Simplex

Frequency

145.20-145.50

145.50-145.80

145.80-146.00

146.01-146.37

146.40-146.58

146.52

146.61-146.97

146.700-147.39

147.42-147.39

147.60-147.99

Usage

Repeater Outputs Misc Experimental OSCAR Subband Repeater Inputs FM Simplex National FM Calling Repeater Outputs Repeater Outputs FM Simplex Repeater Inputs T6-3

FM Voice Operating

• Frequency modulation (FM) is popular mode on VHF/UHF bands.

– Used on both repeaters and simplex modes • Initiating a contact when frequency or repeater is busy – Wait until stations have ended QSO and then call station • Initiating a contact when frequency or repeater is not being used.

– Simply give your call and indicate that you are “listening” T6-4

SSB Voice Operating

• Single side-band (SSB) is the most common voice mode on HF.

• Amateurs normally use the upper sideband of a SSB signal on frequencies higher than 14 Mhz (including VHF and UHF).

• Keep It Plain and Simple – Always speak slowly and clearly.

– Avoid using CW abbreviations or Q signals on voice.

– Use plain language and keep jargon to a minimum.

– Use the phonetic alphabet if the other operator is having problems copying your signal.

T6-5

SSB Voice Operating (Cont’d)

• Initiating A Contact – Listen for stations in a QSO, wait until they have finished and then call one of the stations – Listen for a frequency not being used and call “CQ” for a contact with any station • CQ means “Seek You”: Calling any station • Keep CQ calls short, typically a “3x3” format.

• You can optionally indicate your preference for a contact (DX only, Europe only, particular state, contest participant, etc.) T6-6

Operating CW

• Send Morse code at a speed you can reliably copy.

• The word “DE” is used prior to your call sign to mean “from” or “this is.” • Q signals are used during CW contacts .... not in voice contacts.

• A DX station may be working “split” ... indicating that the station is listening on a frequency or range different from his transmit frequency.

T6-7

Operating CW

Some good guidelines when operating CW: • Listen before transmitting.

• Send short CQs.

• Use only standard abbreviations.

• Use CW prosigns and Q signals properly • Identify at the end of a QSO and every 10 minutes during a QSO.

• Use RST signal report of Readability=5 only if you have received 100% of what the other station has sent.

T6-8

Operating CW

Example of a short CW QSO

CQ CQ CQ DE K0KTY K0KTY K0KTY K K0KTY K0KTY DE K0RGR K0RGR KN K0RGR DE K0KTY R TNX FER CALL. UR RST 579 579. QTH IS ROCHESTER, MN ROCHESTER, MN. NAME IS JOHN JOHN. HW CPY? DE K0KTY KN R R DE K0RGR BT FB COPY JOHN. NAME HR IS BILL ES QTH IS ALSO ROCHESTER, MN. RUNNING QRP RIG TO DIPOLE ANTENNA. BK TO U BK BK BK SOLID COPY BILL. HAVE TO RUN. 73 ES CUL DE K0KTY SK 73 DE K0RGR SK T6-9

The RST System

• • Signal reports when operating CW consists of three digits representing: – Readability (ranges from 1 to 5) – Strength (ranges from 1 to 9) – Tone (ranges from 1 to 9) Signal reports on SSB are two digit numbers using the “RS” portion of the RST system.

– A report of “59 plus 20db” indicates that your report is 20 decibels higher than signal strength 9 on the receiver S meter.

T6-10

The RST System

Readability

1-Unreadable 2-Barely readable 3-Readable with difficulty 4-Readable with no difficulty 5-Perfectly readable

Strength

1-Faint signals bare perceptible 2-Very weak signals 3-Weak signals 4-Fair signals 5-Fairly good signals 6-Good signals 7-Moderately strong signals 8-Strong signals 9-Extremely strong signals

Tone

1-Sixty cycle ac or less, very rough 2-Very rough ac, very harsh and broad 3-Rough ac tone, rectified 4-Rough note, some filtering 5-Filtered rectified ac 6-Filtered tone, trace of tipple 7-Near pure tone, trace of ripple 8-Near perfect tone, trace modulation 9-Perfect tone, no ripple or modulation T6-11

Tuning Up

• To avoid on-the-air interference, connect your transmitter to a “dummy load” while you tune up.

• Once the transmitter is tuned, disconnect the dummy load and connect an antenna. Use an antenna switch to change the connection.

• If you use an antenna tuner to match your antenna with your transmitter, you may have to transmit a brief low power signal to adjust the antenna tuner circuit.

T6-12

Amateur Radio Internet Gateways

• Used to connect amateur stations with the internet.

• Uses the internet protocol known as VoIP (Voice Over Internet Protocol).

• Gateway stations can be used to link repeaters where two distant repeaters share signals using VoIP.

• Popular amateur VoIP linking systems are IRLP and Echolink – KØRGR operates an Echolink node on the 146.625

2 meter repeater in Rochester T6-13

Bandwidth

• The amount of radio-frequency spectrum that a signal occupies is called its

bandwidth

.

• Receiver bandwidth determines how well you can receive one signal in the presence of other signals – Receiver bandwidth selectivity is determined by special intermediate-frequency (IF) filters built into the receiver.

– Some receivers have several IF filters for use when receiving different emission modes.

– CW has the narrowest bandwidth of any emission mode.

T6-14

Relative Emission Bandwidths

T6-15

Typical Emission Bandwidths

Emission Mode

Morse Code (CW) Radio Teletype (RTTY) SSB Voice FM Voice Television (Fast Scan)

Typical Bandwidth

250 to 500 Hz 250 to 500 Hz 2 to 3 KHz 10 to 20 KHz 6 MHz T6-16

FM Bandwidth

• • The frequency of the transmitted RF signal varies with the strength of the modulating voice.

• The

frequency deviation

is the instantaneous change in frequency for a given signal.

FM bandwidth

is twice the maximum frequency deviation plus the maximum modulating audio frequency: BW = 2 x (D + M) BW=bandwidth D = maximum frequency deviation M = maximum modulating audio frequency T6-17

Signal Purity

• An amateur operator is responsible for the quality of the signal transmitted from the amateur station.

• During CW operations, a

chirp

sound is a problem when the transmitter shifts frequency slightly when keyed.

– The problem usually occurs when the oscillator power supply voltage changes as the transmitter is keyed.

– The problem can typically be eliminated by improving the power supply voltage regulation.

T6-18

RF Interference With Other Services

• Receiver Overload – Common type of TV and FM-broadcast interference where a RF signal overloads the first RF amplifier stage of the receiver.

– Most common type of interference caused by VHF and UHF transmitters.

– For overload

from a HF transmitter

, a

high pass filter

should be installed at the TV or FM receiver antenna terminals as a first step to reduce or eliminate receiver overload interference.

T6-19

RF Interference With Other Services

• Harmonic Interference – Occurs when HF transmitters radiates at multiples of the primary transmission frequency.

– May be cured or reduced at the transmitter by installing a

low pass filter

.

– Amateur is responsible to eliminate harmonic interference caused by HF transmissions.

• Telephone Interference – Telephones contain interference protection circuitry.

– Interference may indicate that the telephone was not equipped with interference protection when it was manufactured.

T6-20

RF Interference With Other Services

HF Transmitter TX

Low pass Filter Low Pass Filter Pass Stop freq HF TV TV Receiver High pass filter High Pass Filter Stop Pass freq HF TV T6-21