[Icom] IC756Pro DSP customization

Wed, 12 Feb 2003 17:32:25 -0600

Good summary, Don, and I use similar settings as well.

The filter passband on BPF setting moves with the CW Pitch so that is why
the noise changes "character" somewhat as you place the passband in
different locations in the spectrum of the front-end and antenna noise being
fed to the IF section. Not a fault or drawback - just what happens with a
sophisticated rig like the PRO2. Analog rigs with CW Pitch controls usually
just move the CW BFO around the fixed passband of the crystal filter(s).

I use a completely external audio system feeding either Heil ProSet phones
or a large stereo amp and stereo speaker cabinet. On SSB, the audio is
remarkably smooth and uncommonly clean - witness how an AM broadcast station
sounds, for example.

I have found that it takes a LOT of time and effort to learn how to set up
the PRO and the PRO2 to afford the CW sound that my K2 or 765 provide. But,
the added capabilities of the PROs make it very worthwhile.

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"

----- Original Message -----
From: "Don Rasmussen" <[email protected]>
To: <[email protected]>
Sent: Wednesday, February 12, 2003 3:49 PM
Subject: [Icom] IC756Pro DSP customization

> Hi Guys,
>
> Ever notice how much different the IC756Pro sounds than an analog
> rig in CW mode?
>
> In side by side comparisons using the factory default CW bandwidths,
> it seems there
> is definitely room for improvement with respect to listening
> fatigue.
>
> The biggest change can be seen by a simple increase of the CW pitch
> front panel
> control to 750hz or better. Regardless of the pitch of the signal
> received, the background
> audio changes dramatically based on this control.
>
> It seems that the overall sound of the receiver is a function of
> four factors. The adjustments
> are rarely incremental so you have to try all the settings. What
> sounds "good" is subjective
> of course and the speaker is also important.
>
> The CW setup here:
>
> CW Pitch: 700hz - this is a major factor in how any of the filters
> and PBT adjustments sound.
> FL1 (Wide CW) 800hz Filter, PBT1 +100, PBT2 + 25, bw=650, sft+125 -
> Ultra Quiet.
> FL2 (Narrow CW) 500hz Filter, PBT1 +25, PBT2 (no adjustment),
> bw=450, sft+25
> FL3 (CW Passband Spot) 150hz Filter, bw=150, sft=0
>
> This setup is to minimize the receiver noise and provide a soothing
> tone using
> a large speaker, it's a Drake MS4 here. The filter at 150hz with no
> PBT offset is setup
> so that the receive signal can be accurately centered in the
> passband before going back
> to the 800 or 500hz setup.
>
> This works great here and approximates some of the quieter analog CW
> rigs here. I'd like to
> know if anyone has other preferred settings for these controls on CW
> or phone!
>
> 73,
> > Don Rasmussen
> > Carlsbad, Ca.
> > [email protected]
>
>
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