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Subject: Re: TDR Opportunities
Date: Thu, 09 Jan 2003 10:11:22 -0800
X-Mailer: Mozilla 4.78 [en] (Win98; U)
References: <1072649.9FmG6Dc7aD@mixdown.org> <3E1D2233.67B4@sneakemail.com> <3E1DB592.EEC25E7C@mfi.net>
How does one TDR a phone line?
Mine's got -50V on it; just hooking it up
thru a cap would blast the front end of my TDR.
And if the phone should ring??? Or some other
What's the secret to safe phone line tdr?
Guess with a fast PNP transistor, one could use
phone line's own voltage for the TDR source.
What's the nominal impedance of a phone line in
"Michael A. Terrell" wrote:
> Mike Monett wrote:
> > Andrew Kohlsmith wrote:
> > [...]
> > > I'd be interested in seeing equipment capable of finding faults
> > > (shorts/opens/impedance changes (which is really how these things work,
> > > isn't it?) in phone lines (think unloaded copper) up to 5km. We run into
> > > problems with the telco from time to time where we'd love to be able to say
> > > "we see something about 800m from endpoint A"
> > >
> > > Right now we borrow the cable company's TDR but it's only good for about
> > > 2000 feet.
> > >
> > > What the the resident gurus think about building something, say with a 5%
> > > accuracy which I can hook up to a normal scope?
> > >
> > > Regards,
> > > Andrew
> > This might be what you are looking for. Scroll down to "Build Your Own
> > Cable Radar":
> > http://www.elecdesign.com/1998/oct0198/ifd/1001id.shtml
> > Mike
> Interesting. Another website that doesn't work with Netscape.
> Michael A. Terrell
> Central Florida
Bunch of stuff For Sale and Wanted at the link
Tek 2465, TFT projector, ham radio, 30pS pulser
Tektronix Concept Books...
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