Oscilloscopes - G7SYW's amateur radio bits & bobs...
 

Oscilloscopes

| Posted in Test Equipment

An oscilloscope is a piece of equipment allows you to visually see the electrical signal.

The oscilloscope can be thought of as a time machine, in that it allows you to capture very small slices of time and expand them into a waveform on a screen that would otherwise be impossible to view.

Some of the more elaborate ones may have a storage function present to capture the waveform.
An analogue oscilloscope displays the signal as it happens, because it doesn’t need to digitise the signal before displaying it on the screen, an analogue oscilloscope may be very marginally faster than a comparable digital model. This marginal speed difference is not perceptible to the human eye.

Modern instruments are mainly digital, this can be both a blessing or a curse.
The advantages of a digital oscilloscope are that they can capture single waveforms and store them for later analysis.

The downside of a digital instrument is that the response time, and thus the speed at which signals can be accurately measured and displayed, is dependant on the maximum sampling rate of the main processor and available internal sampling memory.

Of course, modern processing power is very fast, therefore in most day to day uses this limitation causes no problems. It is only in the extreme laboratory uses where it could be cause for concern.


Iso-tek ISR-6051 Oscilloscope

Iso-tek ISR-6051 50MHz oscilloscopeAnother of the most invaluable pieces of equipment when working with radio circuits is the oscilloscope.
In the case of this model, signals up to 50MHz (50 million cycles per second) may be viewed. In reality, signals beyond the manufacturers specified range may be measured and viewed.

The ISO-Tek ISR 6051 oscilloscope is an analogue type of instrument, this makes the response time very fast.

This instrument features two horizontal and two vertical cursors. Because adjustment of the cursor positions are independent of each other this allows easy measurement of the signal amplitude and/or frequency to be made.


Tektronix TDS320 100MHz oscilloscope

Tektronix TDS320 100MHz oscilloscopeThis model of scope can handle input signals up to 100MHz. This is twice as fast as the Iso-tek scope.

The Tektronix TDS 320 is an early (first introduced way back in 1994) digital storage scope. Because of it’s age, the response time can seem slow when compared to modern machines. However, it does have a very handy “Autoset” function.
The autoset function allows you to press a button and the instrument will adjust it’s operating parameters to give the best display of the signal under test.