[ICOM] Re:ICOM] TX audio on 775

[Jim M.]

It is possible to disable the DSP in the 775 and have all SSB generation 
done in analog rather than digital fashion.  Would be interesting to see if 
the problem persists after the DSP is disabled for Tx.  (It can be disabled 
from the front panel menu).


----- Original Message ----- 
From: "Adam Farson" <farson at shaw.ca>
To: "'ICOM Reflector'" <icom at mailman.qth.net>
Sent: Sunday, October 15, 2006 1:25 PM
Subject: RE: [ICOM] Re:ICOM] TX audio on 775


> Hi Clete,
>
> Correction...it is not a compandor; it is a compressor. There is no
> complementary expansion function in the receiver.
>
> In the IC-775 series, the compressor is an analogue circuit in the 455 kHz
> TX IF chain. In the newer IF-DSP-based Icom transceivers (IC-756Pro 
> series,
> IC-7800, IC-746Pro, IC-7000) it is a process in the DSP algorithm.
>
> I remember the old echo suppressors from my years in the telecom industry.
> They were analogue, and DSP-based adaptive echo cancellers replaced them.
>
> There is a general article on compression on my website.
>
> http://www.ab4oj.com/icom/ssbcomp.html
>
> Cheers for now, 73,
> Adam VA7OJ/AB4OJ
>
>
>
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