[R-390] R392 Audio

[Bob Camp]

Hi

This is a slippery slope. Once you start going solid state on the 392, where do you stop? 

The whole audio section of the radio could be converted without a lot of crazy work. That drops three tubes. Then there’s the detector and noise limiter. Then the squelch stuff and squelch diode. Except for some diodes, it’s all audio. Solid state audio of this nature is pretty simple. 

That’s a lot of heat out of the radio. I’d also bet it could be done in a way that would make the radio work better. The radio is sort of a bit of this and a bit of that once you are done. Not really an R382 any more. 

Bob


On Jan 25, 2014, at 2:40 AM, Drew P. <drewrailleur807 at yahoo.com> wrote:

> Perry wrote:
> 
> "Perhaps a simpler alternate to Charles tube re-design of the audio output
> circuit would be to use one the LM series of audio output IC's.  They range
> from 2 to 70 watts or so output and many have been designed for high-end
> audiophile equipment so they have low THD.  Besides needing minimum
> additional components to use, most are under $10.'
> 
> Simpler yet would be to bring out the audio at low level, before the R-392 output stage, and feed it to an amplified computer speaker.  Some of these sound pretty decent, at least as compared to typical communications receiver audio, and many of them use the LM series of audio output IC's.
> 
> Drew
> 
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