[Ham-Mac] cocoaModem Observations & ?

[James Duffey]

Brian - One of the things I discovered early on in running digital  
programs, not just CocoaModem, is that there are a plethora of ways  
to adjust the audio levels.

The setup here is a Kenwood TS850SAT speaker out to a Timewave DSP-59 
+ line out to a iMac line in/USB out to the Mac USB in. So I have 4  
places to adjust the volume, the rig RF gain, the rig AF gain, the  
iMic input settings on the Mac system preferences,  and the input  
level on CocoaModem. I monitor the audio with the speaker out of the  
Timewave, which can be varied by the front panel volume control  
without affecting the audio level to CocoaModem. All of these level  
controls are currently on what i consider to be  normal settings;  
that is none are at maximum.  The trick is to adjust each so that  
they maximize dynamic range while contributing little to the noise.  
This is usually accomplished by having more gain early in the chain,  
that is at the rig.

The AGC at any stage is gain control as well. You just don't have  
control over it. I run the rig and the DSP with the AGC off, again to  
maximize dynamic range, particularly on weak signals.

I am seriously considering adding a digiKeyer or microKeyer to the  
setup. In the information on the web site, I have not located what  
the conversion dynamic range (A to D bits) is on the CoDec sound chip  
they employ. Do you or anyone else on the list know what this is? If  
it is an improvement over the iMic's 16 bits, I may spring for the  
digiKeyer, otherwise as a primarily CW op, the microKeyer seems to be  
more useful.

I think that you will be happy with CocoaModem. - Duffey