[R-390] 390A audio

[Jim M.]

I have good audio with a bookshelf speaker, after doing the capacitor 
replacement in the audio module  suggested by one of the modifications.  I 
also use a matching transformer to match the 600 ohm audio output of the 
radio to an 8 ohm speaker.  Without the matching transformer, the audio will 
sound a bit weak and thin.  Hammond makes a good quality matching 
transformer if you can find one. For AM broadcast reception, the 8 khz 
filter setting works well, anything less will reduce "high" fidelity.  But 
keep in mind that the average AM broadcast bandwidth is not very wide, so 
don't expect a lot of "highs" in the audio...it's not a 20 kHz FM stereo 
signal!


----- Original Message ----- 
From: "Rasputin Novgorod" <priapulus at yahoo.com>
To: <r-390 at mailman.qth.net>
Sent: Monday, September 03, 2007 1:11 AM
Subject: [R-390] 390A audio


> I'm not very happy with my audio. I'm no expert at
> this, but looking at the schematic, I wonder if I couldn't
> pickoff low level audio from the "Diode" pin 14 at the
> back panel and feed it to an external high impedance input
> audio amplifier & speaker?
>
> I've read about the cap mods.
>
> Sincerely
> /b
>
>
>
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