Alex Discovers Amateur Radio

How did Matty make the

signal so clear at the

end? It was terrible

at the start.

Sounds complicated all

this

audio stage

and

Yes but you don’t

have

understand what’s going

on inside to use it.

Good, but I would like to learn

more about how it works once

I know how to use the controls.

Different radios have slightly different

controls, some easier to use than others,

but they all do much the same thing …

IF-DSP

is before

the

audio stage

that makes it

more effective.

… they shape the incoming

radio signal to get rid of any

interference and focus on the

signal you want to listen to

There are a number of reasons why the call could have

suddenly come in so strong: the other station might have

increased their power; a change in the atmosphere could

have improved propagation; Matty could have adjusted the

receiver controls – in particular the

DSP

…

… Simple

DSP

is like the

sound card on a computer

– it digitally processes an

audio signal.

The what?

DSP - DIGITAL SIGNAL PROCESSING

Roger Whisky 1 Alpha

Whisky you are 5 and

9 - 1036 in Wallasey –

good luck in the contest.

QRZ from, from Mike 3

Uniform Alpha Yankee

Today all this filtering and processing can be carried out by a home computer running the

correct program. This is called

oftware

efined

adio -

SDR.

A radio receiver has several

main stages. The Tuning and Radio Frequency (RF) stage which tunes in the wanted signal

from the antenna and amplifies it. The Intermediate Frequency (IF) stage that provides more

amplification and filtering out of unwanted signals. The detector which recovers (demodulates)

the original audio signal. The Audio Amplifier which amplifies the audio signal.

DSP

Filter

Analogue

Signal