[VoIP] New Question - Problem Solved

[ikjtel]

Paul

As you of all people would know, this isn't the first
instance where this class of FXO hardware has failed
to handle signals that it should handle properly... 
Probably not even the second...

Max

--- Paul Wills <pdwills at cedarknolltelephone.com>
wrote:

> I didn't make the "fix" permanent yet but I found
> two problems.
> 
> Putting an inductor in series with the tone source
> filtered out the high 
> frequency stuff that was preventing the FXO card
> from working properly.  I 
> was still getting a "break" in the middle of the
> tone burst though.
> 
> That turned out to be caused by an inductive "kick"
> caused by the chime 
> relay opening.  Although there is no direct path to
> the audio circuit, I can 
> see it coupling through the cable plant or power
> feed supplying the code 
> call unit.  A little Western Electric RC network did
> the job there.  All is 
> well.
> 
> I will permanently install the components tonight. 
> In the mean time, 
> there's always clip leads.
> 
> Sheesh!  You would think that Automatic Electric
> would anticipate such 
> problems when they designed their stuff back in the
> 1920's.  ;-)
> 
> PDW
> 
> ----- Original Message ----- 
> From: "Paul Wills" <pdwills at cedarknolltelephone.com>
> To: "ikjtel" <ikj1234i at yahoo.com>; "Voice Over IP
> Tandem for Analog 
> Switches" <voip at ckts.info>
> Sent: Saturday, December 02, 2006 8:03 AM
> Subject: Re: [VoIP] New Question
> 
> 
> > Max, et al;
> >
> > The tone level *sounds* low but I'm starting to
> suspect that there are 
> > some
> > high frequency harmonics that are messing things
> up.  (After all, the tone
> > source is a buzzer.)  I am going to play with some
> filtering later today 
> > to
> > see if that helps.
> >
> > PDW
> >
> >
> > ----- Original Message ----- 
> > From: "ikjtel" <ikj1234i at yahoo.com>
> > To: "Voice Over IP Tandem for Analog Switches"
> <voip at ckts.info>; "Paul
> > Wills" <pdwills at cedarknolltelephone.com>
> > Sent: Friday, December 01, 2006 10:45 PM
> > Subject: Re: [VoIP] New Question
> >
> >
> >>
> >> Paul
> >>
> >> I'm still skeptical that the echo cancellation
> stuff
> >> has anything to do with the audio problem...
> >>
> >> First, the audio in question wouldn't get
> suppressed
> >> in the first place, because it's flowing in the
> >> opposite direction from which the canceller is in
> >> effect!
> >>
> >> Second, cancellation is rarely perfect, yet you
> >> reported "silence", not "attenuated"...
> >>
> >> Third, cancellation would be all-or-nothing and
> >> wouldn't selectively affect only the "first
> syllable"
> >> like that...
> >>
> >> How hard would it be to try lowering the tone
> level?
> >>
> >> Max
> >>
> >>
> 
> 
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> 
> 



 
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