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Re: internet outages

On 12/23/2018 04:24 PM, David Christensen wrote:
On 12/23/18 12:11 PM, rhkramer@xxxxxxxxx wrote:
On Sunday, December 23, 2018 02:50:34 PM David Christensen wrote:
On 12/23/18 2:02 AM, Curt wrote:
On 2018-12-22, David Christensen <dpchrist@xxxxxxxxxxxxxxxx> wrote:
1.  Test and verify your network cables:


I think in my particular home situation I'd rather just replace my 10
dollar ethernet cable with a new one (or swap in a new one to see if it
makes some appreciable difference) than purchase an $80 device to test
whether it's failing or not (in which former case I'd then be out $90,
which is a real nice load of money).

If you own a continuity tester or multimeter, you could build a pair of
RJ-45 jacks with pigtails for a few dollars and use those to test your

Wow, for $80 I would have expected something that would measure dB loss and
maybe even a time domain reflectometer (well, maybe not that).

Please provide a URL for such test instrument(s).

One other point -- MRSP is not the same a street price:


I have seen those continuity type testers on ebay for under $10 (the test sets with two devices, both with RJ-45 jacks, you plug the ends of the cable into those (one at each end of the cable), and then the "master device" tells you
whether the pairs are connected properly and there is continuity).

I am sure there are cheap clones and/or counterfeits of the LinkMaster available. I prefer genuine, reputable brands.


RE: Time Domain Reflectometer:

Theoretically, you can build your own with a fast pulse generator and an oscilloscope. The trick is, you need a REALLY FAST oscilloscope! The pulse generator is easy, just a couple of transistors, maybe a diode. The circuit is probably in every edition of the Radio Amateur's Handbook. The scope is expensive. If you don't have at least a 1GHz digital sampling scope, don't bother!

--doug, WA2SAY, retired RF engineer