FM radio with impedence 5 Ohm output

[SureshT]

Hello,

I have an old FM radio which has a speaker out put of 5Ω Impedance. Just wondering if I could use normal computer speaker with it ?

 

[Colin Mitchell]

The lettering may be 8ohm but some of the lettering may be missing.
You can connect 8 ohm speaker

 

[SureshT]

That means I can connect a normal PC speaker ?

 

[Colin Mitchell]

You can connect any impedance speaker to the output. The volume will depend on the impedance and the size of the cone.
With low wattage amplifiers, you can connect any impedance to the output.

 

[duke37]

Depends what you mean by PC speaker. These often contain a powr supply and amplifier. All you need is the basic speaker.

If you wish to use a PC speaker which takes its signal from an audio card, then you will need to attenuate the signal from the radio.

 

[SureshT]

a PC speaker which takes its signal from an audio card, then you will need to attenuate the signal

Yes, the same. How can I attenuate the signal ?

 

[duke37]

If it is an old radio, it will have valves, if it is newish, it will have transitors.

A valve radio must have a speaker load or things can go horribly wrong. Put a resistor, 5Ω to 10Ω across the output and put a potentiometer, 100Ω to 1000Ω across this and take the output from the ground (earth) connection and the slider. Start with a moderate volume setting on the radio and adjust the poentiometer to give a suitable level.

A transistor radio may be stable without the load resistor but it will not be harmful.

 

[davenn]

Yes, the same. How can I attenuate the signal ?

the radio will have a volume control doesn't it ??
that's your variable attenuator

 

[SureshT]

It is at least 15 years old. And yes, it has a volume control which at minimum turns off the radio.