On Tue, 09 Oct 2012 16:02:33 -0500, John S
wrote:

On 10/9/2012 2:16 PM, Jeff Liebermann wrote:
Also look on eBay for a Tekronix 1502, 1503c or similar TDR.

I have a 1502. I want something which will give me info within tenth of
an inch on a PCB.

That's not going to happen with my home made TDR. The speed-o-lite is
about 1ft per nanosecond. To see 0.1 inches, you'll need a resolution
of:
0.1in / 12in/nsec = 8.3 picoseconds
That can be done, but not with commodity hardware.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558