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Re: [TenTec] The Bug

To: tentec@contesting.com
Subject: Re: [TenTec] The Bug
From: Mike Gorniak <mgorniak@genesiswireless.us>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 06 Apr 2006 09:01:47 -0500
List-post: <mailto:tentec@contesting.com>
Martin,

The most telling difference between V1 and V2 software, with respect to 
transmit audio quality, can be observed using an  external  receiver and 
an Audio Editing program such as Cool Edit or Adobe Audition.. Viewing 
the recovered waveform of normal speech on V2 reveals a distinctively 
clipped waveform that is very different from  V1.

No amount of input level manipulation or gain adjustment on the Orion 
can make it go away, which seems to indicate that this is happening 
someplace after the first audio amplification stage. Quantifying this as 
a "measurement" of some kind is a bit tricky, but I can assure you that 
the results are quite audible. For all of science's sophistication with 
measurement techniques, nothing accurately quantifies the audible 
effects of clipping. What IS known is that optimal interstage audio gain 
structure can completely eliminate it. As a general rule, an audio 
circuit  will typically allow at least 10db of headroom between the  
nominal operating level and the clipping point. That number can vary 
considerably, depending on what the intended function of the circuit is 
and whether or not the dynamic range of the input audio has been  
modified prior to application.

My guess is that we have an audio stage being run too close to it's 
clipping point. This audio stage is controlled in software, and is not 
user adjustable. The increase of sensitivity with respect to levels on 
both the microphone and auxiliary inputs seem to support this theory.

73,

Mike
NM7X
> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com]On Behalf Of Martin, AA6E
> Sent: Wednesday, April 05, 2006 9:03 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] The Bug
>
>
> I don't have an opinion about O2 sound vs O1 (V1) or O1 (V2), but I would
> like to see measurements instead of comments like "not robust".  I haven't
> got a clue what robust sound is!
>
> 73 Martin AA6E
>
> On 4/5/06, Toby Pennington <toby423@earthlink.net> wrote:
>   
>> I haven't heard a really good sounding O2 yet.  OK, Yes,  but not like the
>> robust audio coming out of the V1 firmware on the Classic Orion.   Toby
>> W4CAK
>>
>>
>>     
>   
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