[TenTec] Loss of Audio in 2054

[Toby Pennington]

I found the RX EQ functioned very well in 1.xxx version,  in fact, now that
you have brought it up,  the new 2054 RX  EQ seems to be acting like a
volume control as it is turned from +20 to -20,  instead of acting like a
tone control it seems to act like a volume control.

Alan, I am not quite clear about having twice the DSP filtering.  Exactly
how is this accomplished?  If in 1.xxx versions we had both an AF Gain and
an IF AGC,  and this resulted in better leveling of the overall audio,  what
is happening now to produce twice the DSP filtering which results in
significant loss of audio below 200hz. Also, is this really desirable in
order to gain a very slight reduction in noise?

However,  I really appreciate you sharing what might be considered
confidentional information so that we might grasp exactly what is going on.

Toby  W4CAK


----- Original Message ----- 
From: "Alan Sewell" <alan.n5na at gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Wednesday, February 15, 2006 10:52 AM
Subject: Re: [TenTec] Loss of Audio in 2054


> I may be out of place posting this but Gary explained the reduction in
> audio to the beta group as follows:
>
> "The V1 firmware contained an AF AGC in addition to the IF AGC. This
> resulted in a better leveling of the overall audio but at the cost of
> adding to noise levels and effectively canceling the RX EQ functions.
> V2 doesn't add leveling to the audio. In places where there is some
> impact on the audio levels, like below 150 Hz the V2 version makes it
> worse because we run twice the DSP filtering that was in the V1
> firmware."
>
>
> I think that explains it a bit better than the FAQ.
>
> 73,
>
> Alan  N5NA
>
>
> Toby Pennington wrote:
> > The loss of audio between 200hz and 100hz when in cw mode is problematic
for me,  even though I have seen some posts that indicate it is not big deal
for others.
> >
> > I commonly narrow down the cw filters to 100hz which eliminates a lot of
noise,  especially Qrn type noise.  I am further disappointed that Ten Tec
has come to the conclusion that this behaviour is an acceptable trait of the
DSP filter as explained in their faq notes.  This indicates to me that they
have tried to fix this problem,  but have been unable to and need to offer a
plausable explanation as to why it is happening.
> >
> > I don't buy that!   This loss of audio was never an issue in the 1.xxx
versions.  You can turn down the BW to 100hz and have the same audio
strength that you had at 200Hz.  IF the loss of audio is inherent then why
does it not happen in 1.xxx versions.
> >
> > I believe this needs looking into further and not just glossed over with
a sentence or two explaining it away.  If anyone has additional information
which could shed some light on this subject I would like to see it.
> >
> > Toby  W4CAK
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> >
>
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