[TenTec] AM Receiver distortion in Orion II

[Carl Moreschi]

The Orion recording has more bass and less highs.  With a 6 khz filter in
the Orion, the audio passband is 3 khz on each side of the carrier.  I would
expect this to sound bassy and have less highs.  But the quality is
excellent.  The 870 recording clearly shows that the bandwidth is much
greater than 3 khz which would only allow 1500 hertz of each side of the
carrier.  I bet the 870 has a special AM filter that is in the 9 khz or
higher range that switches in automatically in AM.  It is impossible for the
870 AM audio to sound like this with only 3 khz BW.  Both audios are
excellent considering the BW.

Carl Moreschi N4PY
121 Little Bell Drive
Bell Mountain
Hays, NC 28635
----- Original Message ----- 
From: "Ron Castro" <ronc at sonic.net>
To: "Ten Tec List" <tentec at contesting.com>
Sent: Tuesday, January 23, 2007 5:54 PM
Subject: [TenTec] AM Receiver distortion in Orion II


> One of the items on my "wish list" for the Orion II is to fix the AM
receive audio, which sounds to me like a problem in the DSP code that causes
distortion and 'muddy' sound.  It's most noticeable during selective fades
that cause a serious clipping effect.  Last night, I made an MP3 of a local
AM radio station comparing the O2 to a TS-870, and sent it to TT service.
This morning, TT said they couldn't hear any difference between the two
receivers.  Is it my ears or what?  The link to the clip is below.  The O2
is the first 60 seconds and the 870 is the second 60 seconds.  Bandwidth on
the O2 is 6 kHz, while the 870 is 3 kHz, although as you'll hear, it sounds
just the opposite!
>
> http://n6ie.com/OrionII_vs_870.mp3
>
> Can anyone besides me hear the difference?
>
>       Ron N6IE
>  www.N6IE.com
> (Formerly N6AHA)
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