[TenTec] AM Receiver distortion in Orion II

[Carl Moreschi]

I have one other thought with regards to V1 and V2 on the Orion.  On AM, the
bandwidth with V1 is actually double the filter size.  So a 6 khz filter on
V1 is actually 12 khz which is 6 khz each side of the carrier.  In V2, the 6
khz filter is really 6 khz which is 3 khz each side of the carrier.  The end
result is the wider bandwidth available in V1 should make V1 sound much
nicer.  V2 really needs an 8 k selection for AM.  The funny thing about this
is way back when the rx320 first came out, the maximum bandwidth was 6 khz.
But people complained about AM fidelity and they added an 8 khz filter for
AM in the second firmware release.

Carl Moreschi N4PY
121 Little Bell Drive
Bell Mountain
Hays, NC 28635
----- Original Message ----- 
From: "Larry Menzel" <retire at means.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Tuesday, January 23, 2007 9:17 PM
Subject: Re: [TenTec] AM Receiver distortion in Orion II


> Number 1, I think it depends in large measure on the quality of the
> playback.  I listened first on my stereo speakers on my computer and I
> varied the bass as I listened.  I had to lower the bass response on the
> Orion bit, and increase it on the Kenwood part to make either sound like
> "normal" AM audio.  I agree with Carl,  it would seem that the Kenwood bit
> is too good for a 3KHz passband.
>
> Number 2, There is clearly a difference between the two recordings, so
maybe
> someone in Tennessee has a tin ear?   Hey...poking a little fun
> here....nothing serious.
>
> I think both recordings when played back on a good sound reproduction
system
> sound excellent.  The "muddy" factor, I suppose is simply the bass
response
> on a particular play back system.
>
> Larry, N0XB
>
>
>
> ----- Original Message ----- 
> From: "Dennis Jones" <k6rcl at cox.net>
> To: "Ron Castro" <ronc at sonic.net>; "Discussion of Ten-Tec Equipment"
> <tentec at contesting.com>
> Cc: "Dennis Jones" <k6rcl at cox.net>
> Sent: Tuesday, January 23, 2007 7:05 PM
> Subject: Re: [TenTec] AM Receiver distortion in Orion II
>
>
> > Ron,
> >
> > Sounds good to me, in fact quite good.
> >
> > DJ  K6RCL
> >
> >
> > On Jan 23, 2007, at 2:54 PM, Ron Castro wrote:
> >
> >> 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)
> >> _______________________________________________
> >> TenTec mailing list
> >> TenTec at contesting.com
> >> http://lists.contesting.com/mailman/listinfo/tentec
> >
> > Dennis Jones
> > k6rcl at cox.net
> >
> >
> >
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