[TenTec] O2 AM Distortion FIXED!

[Ron Castro]

The new audio clips comparing the two receivers is currently posted on my 
site at www.n6ie.com.  The clips are about 1 MB each, so if you have 
dial-up, it could take some time.

BTW...my website has no ads, no music, no annoying 'dancing graphics', etc.!

      Ron Castro
Chief Technical Officer
  Results Radio, LLC
          N6IE
 www.N6IE.com
(Formerly N6AHA)

----- Original Message ----- 
From: "Ron Castro" <ronc at sonic.net>
To: "Ten Tec List" <tentec at contesting.com>
Sent: Wednesday, January 24, 2007 10:04 PM
Subject: [TenTec] O2 AM Distortion FIXED!


>I got a nice e-mail from Jack Burchfield at Ten Tec about the AM distortion 
>problem.  He listened to my recording and agreed that the Orion II didn't 
>sound as good as it should, and explained that the dual-loop AGC system 
>with the new adjustable hang time has to be slowed down to sound good in 
>AM.  He suggested using a hang of 3 to 4 seconds.
>
> I increased the hang time to 4 seconds and that cured the distortion!  I 
> didn't realize that the two AGC loops were so independent and I had been 
> thinking that a slow decay time coupled with a hang time of more like .5 
> seconds would eliminate AGC distortion from the equation.  It does take a 
> very long hang to clean up the sound.  The short hang time is apparently 
> what was causing the clipping and the "crunched" sound due to severe loss 
> of dynamic range.
>
> I made a new recording that I will place on my website later that 
> demonstrates how AM sounds when the settings are changed.  I recorded a 40 
> meter short-wave broadcast station on both receivers simultaneously with 
> the 870 in the left channel and the O2 in the right.  I split the channels 
> and made separate MP3 files of each radio.  I also backed off the 
> bandwidth of 870 and matched the O2 so the -3 dB points were at the exact 
> same frequency.  Both receivers were fed from a T connector to the same 
> antenna.  The results were outstanding!  The only noticeable difference is 
> the AGC action, and that the O2 handled the really deep fades better than 
> the 870.
>
> Good work TT!  I'll mark that off the 'fix' list...
>
>      Ron N6IE
> www.N6IE.com
> (Formerly N6AHA)
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
>