SYS: ONLINE|UTC --:--:--|BAND: Audio
SWR: 1.2PWR: 100WQTH: EN52
Test Equipment

Oscilloscope

See the waveform. The instrument that turns "it sounds odd" into a measurement.

Oscilloscope engineering reference drawing
Specification summary
Bandwidth50-100 MHz is ample for station audio and supply work
ChannelsTwo, so input and output can be compared
Sample rateAt least five times the bandwidth
Vertical resolution8 bit typical, 12 bit on better instruments
TimebaseFrom nanoseconds to seconds per division
Probes10:1 passive probes for general work
MeasurementAutomatic rise time, frequency, peak-to-peak, RMS
Stage: Test
BW: 100 MHzch: 2fs: 1 GS/sbits: 8

Overview

An oscilloscope plots voltage against time. In an amateur station that makes it the right tool for looking at audio, envelope and low-frequency signals: the shape of a CW keying envelope, the presence of flat-topping on a speech signal, the ripple on a power supply, or the output of a keyer.

A modern digital scope with a bandwidth of 100 MHz is more than adequate for station audio work and supply diagnostics. It is not a spectrum analyser, and it cannot show you the frequency domain, but for anything that varies in time it is unmatched.

Bands and modes

Band coverage

AudioDCLow frequency

Modes

Measurement only

Safety note

Never connect an oscilloscope ground clip to a point that is not at earth potential — doing so shorts that point to earth through the probe lead and can destroy the instrument or injure you. Use an isolation transformer or a differential probe when measuring mains-referenced circuits.

Using it well

  • Use a 10:1 probe and remember to set the same ratio on the scope.
  • Look at the CW envelope for clicks and the SSB envelope for flat-topping.
  • Check power supply ripple at the radio end of the cable, under load.
  • Trigger on the signal you care about rather than free-running.
Reference material for educational use. Nothing on this page is a recommendation to buy a particular product, and no communication distance or performance is promised. Confirm figures against the equipment you actually have and against the regulations that apply where you operate.
Related

References that go with this one

Multimeter engineering reference drawing
Test

Multimeter

The first instrument anyone should own. Voltage, current, resistance and continuity.

Vdc: 600 VI: 10 A
Test Gear→
Power Supply engineering reference drawing
Power

Power Supply

Clean regulated DC for the station, sized for the current the radio actually draws.

V: 13.8 VI: 30 A
Power→
Frequency Counter engineering reference drawing
Test

Frequency Counter

An independent frequency reference, for checking calibration and measuring carriers.

f: 0.1 Hz-3 GHzgate: 1 s
Test Gear→
CW Keyer engineering reference drawing
Operate

CW Keyer

Electronic timing for Morse, so your sending is clean regardless of your hand.

wpm: 5-40tone: 600 Hz
Operating→

Tool Categories

Transceivers & AntennasFeedline & ConnectorsPower & GroundingTest EquipmentOperating & Logging

Site

AboutContactPrivacyBlog3D StudioSearch