[mythtv-users] Power Line Network Connections and Myth ?

Simon Hobson linux at thehobsons.co.uk
Sun Oct 3 08:08:59 UTC 2010


sean darcy wrote:

>I'm planning on setting up an FE in a cabin about 150 yards from the
>house. I could run CAT 5E, but it's a long way, and the cable would be
>exposed to rain, snow, etc. Instead I'm thinking of Powerline over a
>dedicated electric cable. I run outdoor rated electric cable with an
>outlet at each end. No connection to the electric system at either
>end. Then use 2 Powerline adapters.
>
>Would this work? Is it a good idea?

OK, so what you are saying is that instead of running a cable, you 
are going to run a cable !

Do yourself a favour - run a data cable, not a cable that was never 
intended to be used for data. As already said, you can buy outdoor 
rated Cat5, and in my experience, even standard cable tends to last 
longer than you might think. 150m is longer than the spec, but I did 
do 180m once and it still worked. Even if it doesn't work for 
ethernet, you would then have four pairs to run something like VDSL 
over.
In effect, you use similar kit to that used to provide ADSL internet 
services to pur data over one or two copper pairs. Short 
distance=high speed. I did that once for a customer at work, he 
wanted to link his house to the farm over about 200m of standard 
phone cable he'd had the foresight to install. We ran the kit at 
25mbps FDX, it would probably have done 50mbps but I didn't get round 
to trying that. That was several years ago, so I imagine things might 
have improved speed wise since.
Not sure if these were the actual units we used, but probably the same range
http://www.patton.com/products/pe_products.asp?category=355&tab=ov

I'd be very surprised if you couldn't find something a bit less 
pricey than those, and if you find something that can use 2 pairs, it 
should be faster.


BTW - this is almost the same as what the powerline adapters are 
doing - but without the unbelievably rubbish cable and interfering Ac 
supply.

 From http://en.wikipedia.org/wiki/Very-high-bitrate_digital_subscriber_line
>Second-generation systems (VDSL2; ITU-T G.993.2 approved in February 
>2006) utilize frequencies of up to 30 MHz to provide data rates 
>exceeding 100 Mbit/s simultaneously in both the upstream and 
>downstream directions. The maximum available bit rate is achieved at 
>a range of about 300 meters; performance degrades as the loop 
>attenuation increases.

So try a plain cat 5 connection first, and if it doesn't work, you 
know you can put boxes on the ends that will make it work - reliably.

Of course, what you shoudl really do is use fibre - that will avoid 
all the potential problems from ground differentials. Such 
differentials can cause some significant damage during thunderstorms 
when it's not hard to see short spikes to thousands of volts. 
Ethernet does have isolating transformers at each end, but it's 
certainly not immune to the problem.

-- 
Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.


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