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[TenTec] AGC: ON or OFF Survey

To: <tentec@contesting.com>
Subject: [TenTec] AGC: ON or OFF Survey
From: ac5aa@juno.com (ac5aa@juno.com)
Date: Mon, 5 Jul 1999 15:07:27 -0500
I use NR on CW almost all the time - the difference in readability of
many signals is very noticeable.  But, I like to chase the ones down in
the noise - I almost never tune to S5 or over as they tend to be
stateside and I prefer DX chasing.  So, your milage may vary.  I also use
LP, with it set to 800 HZ rolloff freq on CW.  

On SSB, I tend to start with NR off, then add if needed.  Same with LP. 
On SSB I have LP set to 1200 Hz rolloff.  Sometimes intelligibility
suffers on SSB, where on CW the difference is often amazing.  It all
depends on the type of noise you're combating.  I'm in suburban
neighborhood housing, and it works quite well for me.  

I've heard as many opinions on DSP as there are people - I don't know the
entire reason for that.  Perhaps some don't know what it's doing and how,
so they don't have realistic expectations for it.  But, maybe they do,
and it just doesn't work for their ears.  A very famous DXer in this area
tried one on SSB and said he much prefers his "built in" filtering (i.e.,
his brain).  But I think SSB is the biggest challenge for these filters,
and they work better on CW.  It didn't help that he also chose a filter
that is commonly not considered to be very good.  I won't name names on
the reflector.  The Ten-Tec implementation of an audio DSP is quite good,
although sometimes I wish it were able to handle more diverse noise
types, and I miss the infinite variability of my NIR-12 at other times. 
Still, for a one-button DSP, it's the best I've heard, and I've heard
them all.  


        73,  Duane 

On Mon, 5 Jul 1999 11:56:51 -0700 (PDT) N1EU <n1eu@yahoo.com> writes:
>
>(In response to Jim's polling of AGC use on cw)
>
>Must confess to hardly ever leaving fast AGC mode,
>although I will start experimenting on cw with it off.
>
>If I could interject another question into this
>discussion or perhaps start another one on DSP:
>
>As a relative Omni newcomer, I'm a little confused
>about the heaps of praise being bestowed on the Omni's
>DSP in many recent postings.  Please correct me, but
>isn't the DSP limited to auto notch filter, low pass
>filtering and noise reduction (guess you might call it
>audio peaking Jim)?  I think they work okay, don't use
>them all that much, but I can't help but think I'm
>missing something when I hear so much praise for them.
> Occasionally the NR will help make a barely readable
>signal more readable in QRN, autonotch might reject
>the jerk tuning up on a SSB QSO freq and lastly, I
>probably should try using LP more in crowded SSB
>condx.  That's about the extent of how I imagine using
>the Omni's DSP.  Any hints on making the most of the
>DSP that I (& others) might be missing out on?
>
>73,
>Barry  N1EU
>
>--- Jim Reid <jreid@aloha.net> wrote:
>> 
>> Hi,
>> 
>> How many of you,  when on CW,  run the "old" way:
>> 
>> Turn the AGC OFF,  with the RF gain backed off,  and
>> with the audio turned full up.  That's the way we
>> did it in
>> the old days using the tube rigs.   You adjusted the
>> 
>> "loudness" of the signal which you listened to with
>> the RF gain control.
>> 
>> Benefit of this method  is/was  to keep the noise
>> level down,
>> now however,  with the OmniVI+,  with the in-built,
>> IF filters,
>> combined DSP and CW audio peaking,  I find the "old"
>> way not that useful anymore.  Any still using it? 
>> If so,
>> why,  or under what circumstances,  perhaps because
>> you don't have DSP or APF, hi.
>> 
>> 73,  Jim,  KH7M
>> 
>> 
>> 
>> 
>> --
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>> 
>
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Duane A. Calvin, AC5AA
Austin, Texas
ac5aa@juno.com -or- ac5aa@earthlink.net
Day:  dacalvin@us.ibm.com

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