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From: "Bruce Griffiths" <bruce.griffiths@...>
To: [email protected]
Sent: Saturday, July 7, 2018 8:15:53 AM
Subject: Re: [TekScopes] Kludging together a TDR or similar?

Why do you think that the frequency is equal to 1/RC?
Bruce

On 08 July 2018 at 01:03 n4buq <n4buq@...> wrote:


Looking at that schematic, it appears the frequency is determined by C3 and
R1. If I'm not mistaken, the exact values of those components would
result in a frequency of 3.129 kHz; however, the oscilloscope images
appear to show 4.81 kHz. Is that difference due to component tolerances
or is something else at work here?

Thanks,
Barry - N4BUQ

----- Original Message -----

From: "Michael A. Terrell" <mike.terrell@...>
To: [email protected]
Sent: Friday, July 6, 2018 7:32:15 PM
Subject: Re: [TekScopes] Kludging together a TDR or similar?

You can build a simple TDR with a 74AC14, some resistors and a couple
capacitors.
<>

If that doesn't work, it is from this page:


It is sold on Ebay by <> It was
$15.19
a couple months ago. It isn't available right now. I bought one, to test.
If
I like it I will make a surface mount version of it, and put it into a
small
extruded aluminum box. The box, and the three connectors will be about
80%
of the component costs in a SMD version.



Michael A. Terrell


-----Original Message-----

From: cheater cheater <cheater00@...>
Sent: Jun 29, 2018 3:20 AM
To: [email protected]
Subject: Re: [TekScopes] Kludging together a TDR or similar?

hi guys, thanks for the replies.

I don't have the parts necessary to build a pulser. Can I use the
mainframe's pulse generator?

The cable goes from a local distribution box, part underground, part
overground, and then goes to a wall socket used only by my modem. There
is
no splitting and no neighbors using this. The run in my yard that is
overground is maybe 30m at most.

There was no thunder when this stopped working, just heavy rain.