Today I saw a Time Warner Cable minivan trolling through the neighborhood.

It appeared to have a four antenna DF array on the roof with vertical
lengths of about 2-3 feet.

What's up with that?

On Tue, 27 Aug 2013 08:41:02 -0700, "Wayne"
wrote:

Today I saw a Time Warner Cable minivan trolling through the neighborhood.

It appeared to have a four antenna DF array on the roof with vertical
lengths of about 2-3 feet.

What's up with that?

It's a doppler direction finder array, used to locate cable leaks and
ingres (leakage into the cable). Something like these perahaps:
http://kn2c.us/radio-df-ddf2020t/
http://www.wavetracker.com
http://www.google.com/patents/US6801162



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

"Jeff Liebermann" wrote in message
...

On Tue, 27 Aug 2013 08:41:02 -0700, "Wayne"
wrote:

Today I saw a Time Warner Cable minivan trolling through the neighborhood.

It appeared to have a four antenna DF array on the roof with vertical
lengths of about 2-3 feet.

What's up with that?

# It's a doppler direction finder array, used to locate cable leaks and
# ingres (leakage into the cable). Something like these perahaps:
# http://kn2c.us/radio-df-ddf2020t/
# http://www.wavetracker.com
# http://www.google.com/patents/US6801162

Ah yes, mystery solved. The antenna array looked exactly like a
"Wavetracker".

Thanks

Wayne W5GIE
Redlands, CA

"Jeff Liebermann" wrote in message
...
On Tue, 27 Aug 2013 08:41:02 -0700, "Wayne"
wrote:

Today I saw a Time Warner Cable minivan trolling through the neighborhood.

It appeared to have a four antenna DF array on the roof with vertical
lengths of about 2-3 feet.

What's up with that?

It's a doppler direction finder array, used to locate cable leaks and
ingres (leakage into the cable). Something like these perahaps:

I didn't see the Cox survey van on my street but their tech paid me a visit.
I didn't appreciate the extent of it but my interior cabling was leaking.
The tech came to the door and said he had to do some testing on the pole
that would knock out all our services for a few minutes. Was that OK? (Yes)

He reported that my house was the source of leakage that had earlier been
detected by their vehicle. (Oops) He asked if we had any broadcast ingress.
(Yes) Could he fix things inside the house? (Heck yes) He spent over an
hour reterminating some of my old stuff and running a few new pieces for me.
That got the leakage within limits and it made the ingress go away. (Yay)

"Sal"

Sal salmonella@food wrote:

"Jeff Liebermann" wrote in message
...
On Tue, 27 Aug 2013 08:41:02 -0700, "Wayne"
wrote:

Today I saw a Time Warner Cable minivan trolling through the neighborhood.

It appeared to have a four antenna DF array on the roof with vertical
lengths of about 2-3 feet.

What's up with that?

It's a doppler direction finder array, used to locate cable leaks and
ingres (leakage into the cable). Something like these perahaps:

I didn't see the Cox survey van on my street but their tech paid me a visit.
I didn't appreciate the extent of it but my interior cabling was leaking.
The tech came to the door and said he had to do some testing on the pole
that would knock out all our services for a few minutes. Was that OK? (Yes)

He reported that my house was the source of leakage that had earlier been
detected by their vehicle. (Oops) He asked if we had any broadcast ingress.
(Yes) Could he fix things inside the house? (Heck yes) He spent over an
hour reterminating some of my old stuff and running a few new pieces for me.
That got the leakage within limits and it made the ingress go away. (Yay)

"Sal"

And all that in the house of (supposedly) a radio amateur?

Over here the house cabling is the responsibility of the inhabitant.
The cabling company delivers signal to a demarcation point, in new houses
usually in the electricity metering cabinet, in older houses that were
later retrofitted with cable it is often on the outside wall of the living
room. Anything connected there you have to supply and maintain yourself.

The inhouse cabling and especially the connectors have been very
substandard at the time the cable network was deployed, which wasn't a
problem because there were few channels and they were positioned carefully
not to overlap with terrestrial transmission in the area. But when the
DVB-T network was deployed, new channels were used (there was parallal
Analog and DVB-T transmission for a while) and the cable networks were
fully allocated. So you often got a DVB-T transmitter on the same
channel as an analog cable channel, and those DVB-T transmitters are
in the cities instead of the usually more remote sites where the Analog
transmitters were.

Big trouble ensued, and everyone (who cares about picture quality)
was forced to buy new cabling and at least new connectors, that were
actually providing shielding.

This was a big boon for radio amateurs, because it reduced the amount
of all interference, not only from DVB-T to viewers but also from
radio amateurs to viewers and from the cable network to radio amateurs.
(on the cable network, channels are in use that overlap with the 2m
and 70cm amateur bands)

"Rob" wrote in message
...
He reported that my house was the source of leakage that had earlier
been
detected by their vehicle. (Oops) He asked if we had any broadcast
ingress.
(Yes) Could he fix things inside the house? (Heck yes) He spent over
an
hour reterminating some of my old stuff and running a few new pieces for
me.
That got the leakage within limits and it made the ingress go away. (Yay)

"Sal"

And all that in the house of (supposedly) a radio amateur?

Oh, it's even worse than that -- way worse. :-(

Yes, I'm a licensed amateur, Extra Class, even. In February, 2007, I passed
the Extra Exam on my first try without ever cracking a book. I'm a retired
engineer and I knew much of the technical stuff. I could afford some misses
on rules and still pass. I had studied for General because I wanted at
least General. I figured Extra could come later. As it worked out, "later"
was only about half an hour.

But it's even worse than that -- way worse. :-(

A major chunk of my working life was spent dealing with EMI detection and
correction. I was certified as an EMI Engineer by the National Association
of Radio and Telecommunications Engineers. I'd had to find and solve a
whole lot of "tough dogs" in my working life. I just hadn't bothered at
home. I always seemed to have something else to do.

Okay, now that I've humbled myself, you may proceed to bash me. Bashers are
requested to summarize their experience and involvement. Humor is allowed.

"Sal"
KD6VKW (KILO-DELTA-SIX-VICIOUS-KILLER-WEASEL)
B.S., Chapman University, 1989, Electronics
Volunteer Examiner
Emergency Services Volunteer (RACES)
Past President of South Bay Amateur Radio Society, SOBARS
Past Field Day Chairman of SOBARS
Past Treasurer of SOBARS
SOBARS repeater repairman
SOBARS weekly HF net control operator
Recovering Sailor, USN 21 yrs.
Elmer of many
Enemy of none
Newsgroup fun-lover
All-around good-guy

Sal salmonella@food wrote:

"Rob" wrote in message
...
He reported that my house was the source of leakage that had earlier
been
detected by their vehicle. (Oops) He asked if we had any broadcast
ingress.
(Yes) Could he fix things inside the house? (Heck yes) He spent over
an
hour reterminating some of my old stuff and running a few new pieces for
me.
That got the leakage within limits and it made the ingress go away. (Yay)

"Sal"

And all that in the house of (supposedly) a radio amateur?

Oh, it's even worse than that -- way worse. :-(

I often heard that IT is worst within IT companies :-)

On Tue, 27 Aug 2013 23:24:20 -0700, "Sal" salmonella@food
poisoning.org wrote:

He spent over an
hour reterminating some of my old stuff and running a few new pieces for me.
That got the leakage within limits and it made the ingress go away. (Yay)

I've had to deal with cable leakage problems generating interference
to commercial services. Cable CH18 also covers the 2m band.

"Interference Report Card"
http://www.cablefax.com/tech/operations/bestpractices/14955.html
http://www.cablefax.com/tech/sections/columns/broadband/42840.html

Most of the time, it's the ring type crimp F connectors like this:
http://www.showmecables.com/images/catalog/product/F-Type-Connector-With-1-4-Inch-Crimp-Ring-RG59-4.jpg
that caused problems. Occasionally, some really bad RG-59/u with
maybe 50% coverage on the shield. Other times, it various cable
amplifiers, splitters, and devices, usually with unterminated ends or
ports. Lots of ways to do it wrong.

So, what did the Cox guy find? I'm nosey.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 8/28/2013 11:42 AM, Jeff Liebermann wrote:
On Tue, 27 Aug 2013 23:24:20 -0700, "Sal" salmonella@food
poisoning.org wrote:

He spent over an
hour reterminating some of my old stuff and running a few new pieces for me.
That got the leakage within limits and it made the ingress go away. (Yay)

I've had to deal with cable leakage problems generating interference
to commercial services. Cable CH18 also covers the 2m band.

"Interference Report Card"
http://www.cablefax.com/tech/operations/bestpractices/14955.html
http://www.cablefax.com/tech/sections/columns/broadband/42840.html

Most of the time, it's the ring type crimp F connectors like this:
http://www.showmecables.com/images/catalog/product/F-Type-Connector-With-1-4-Inch-Crimp-Ring-RG59-4.jpg
that caused problems.

What type/style F connector would you recommend?

John KD5YI

On Wed, 28 Aug 2013 11:48:04 -0500, John S
wrote:

On 8/28/2013 11:42 AM, Jeff Liebermann wrote:
Most of the time, it's the ring type crimp F connectors like this:
http://www.showmecables.com/images/catalog/product/F-Type-Connector-With-1-4-Inch-Crimp-Ring-RG59-4.jpg
that caused problems.

What type/style F connector would you recommend?
John KD5YI

I steal mine directly from Comcast. I use whatever is available.

The problem is that many manufacturers have put considerable time and
effort into making their connectors as incompatible as possible with
their competitors connectors and tools. Fortunately, there several
good universal compression tools. This is what I settled on mostly
because it seems to fit all the various mutations and will also do BNC
and phono compression connectors:
http://www.ebay.com/itm/221178706506
It's the cheapest, of course. I have much better tools that I also
use, but the above tool works with most everything.

You'll also need a wire stripper.
http://www.ebay.com/itm/310711345790
Buy at least 2 of these, as they tend to wear out (or become borrowed)
rather rapidly.

For connectors, it appears that Comcast likes Thomas and Betts
Smash-N-Seal connectors.
http://www.ebay.com/itm/161090412893
Note that the connectors for RG-59 and RG-6/u are quite different.
There are also different types for double shielded and quad shielded
RG-6/u. Watch the video and you'll see the problem:
http://www.youtube.com/watch?v=HW3L61ydvzM
The SNS1P6U connector is a good choice, because it sorta fits all the
common types of RG-6/u. The compression tool shown in the video is
quite good, has a built in stripper, but will only do F connectors,
not BNC or phono. Plan on ruining a few connectors before you learn
how to use the tool. There are videos on YouTube for how to work with
compression connectors.

Drivel: All of my 50 ohm antennas on my roof are connected to their
respective radios with 75 ohm RG-6/u coax, F connectors, and various
adapters. Also some RG-6/u with BNC compression connectors. No
problems and very little additional mismatch loss.

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