[R-390] Speaker 600

[Bob Camp]

Hi

It's been a *long* time since I have seen a normal sized speaker with a 
600 ohm impedance.

What is normally done is to get a 600 ohm to 8 ohm (or 4 ohm) 
transformer and use a normal speaker. The transformers are available 
from a variety of sources ranging from eBay to Digikey to Radio Shack. 
Typically ones that are big enough to do the job run in the $10 to $20 
range.

Another option is to get one of the military speakers. The ones you 
want have an 8 ohm speaker and a transformer built into the enclosure. 
Some of these can be a little expensive but they often look neat teamed 
up with an R-390.

To get a "true" 600 ohm speaker I would look into the horn speakers you 
commonly see used in stadiums. The horns and drivers are generally sold 
separately. Drivers are available in a variety of impedances including 
600 ohms. I'd have to admit that 600 ohms is not exactly the most 
common driver to find lying around ...

The final option is to pick the audio off the radio at the diode load 
test point and drive it into a high impedance input on a audio 
amplifier. This takes the whole audio section of the R390 out of the 
act. A lot of audio amplifiers will work. A good old tube based mono 
amplifier is often used.

	Take Care!

		Bob



On Sep 22, 2004, at 4:39 PM, Charles B wrote:

> Hi all,
>
> Where can I find a 600 ohm speaker or where can purchase one?
>
> Is it possible to convert an 8 ohm speaker to 600 ohms?
>
> Thanks
>
> Chuck
>
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