"Jeff Liebermann" wrote in message
Trivia: Cable leakage has changed over the last few years. The sync
buzz of the analog TV era has been replaced by digital hiss. Put a
temporary antenna on your cable connection and listen on a suitable
receiver. Some cable systems still carry FM broadcast stations, so he
might also be hearing those coming from a cable leak. Locally,
everything was moved to digital channels in 2005.
http://www.sfgate.com/business/article/Comcast-to-restore-30-FM-radio-stations-Some-2625920.php


I guess it depends on where you are Jeff. Around where I live there about
100 channels that are still analog. Still starting at the old channel 2.

The state I live in is still way behind times.

On Mon, 2 Dec 2013 00:00:37 -0500, "Ralph Mowery"
wrote:

"Jeff Liebermann" wrote in message
Trivia: Cable leakage has changed over the last few years. The sync
buzz of the analog TV era has been replaced by digital hiss. Put a
temporary antenna on your cable connection and listen on a suitable
receiver. Some cable systems still carry FM broadcast stations, so he
might also be hearing those coming from a cable leak. Locally,
everything was moved to digital channels in 2005.
http://www.sfgate.com/business/article/Comcast-to-restore-30-FM-radio-stations-Some-2625920.php

I guess it depends on where you are Jeff. Around where I live there about
100 channels that are still analog. Still starting at the old channel 2.

Comcast is now all digital in the People's Republic of Santa Cruz CA.
Of course Comcast has a new scam. You get up to two "free" DTA boxes:
http://customer.comcast.com/Pages/FAQViewer.aspx?seoid=What-is-a-digital-adapter
for listening to FM and viewing non-HD channels. It was originally
announced that it was "free" for 2 years, but Comcast started adding
$5/month per box to some peoples bills in about June.

One problem is that the DTA box somehow manages to produce worse than
analog quality TV pictures. Digital in, garbage out. I don't know
how they managed it, but the "free" box produces some of the worst
looking pictures I have ever seen since the introduction of color TV.
The Comcast solution is to rent a similar box, that produces HD video,
and amazingly produces decent looking non-HD video for $10/month.
That's $120/year per TV set for what used to be free:
http://bgr.com/2013/10/16/comcast-digital-adapter-criticism/
https://www.google.com/search?q=comcast+dta&tbm=isch
Oddly, both types of DTA boxes use the same digital data for non-HD
stations, so it's not Comcast that's sending garbage video. It's the
DTA box.

Both types of boxes will play some local FM stations, but I've only
tried it on the HD version. Works fine but will vary by area. For
Santa Cruz, we get about 30 stations.

The state I live in is still way behind times.

That may not be such a bad thing.

--
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
...
Comcast is now all digital in the People's Republic of Santa Cruz CA.
Of course Comcast has a new scam. You get up to two "free" DTA boxes:
http://customer.comcast.com/Pages/FAQViewer.aspx?seoid=What-is-a-digital-adapter
for listening to FM and viewing non-HD channels. It was originally
announced that it was "free" for 2 years, but Comcast started adding
$5/month per box to some peoples bills in about June.

One problem is that the DTA box somehow manages to produce worse than
analog quality TV pictures. Digital in, garbage out. I don't know
how they managed it, but the "free" box produces some of the worst
looking pictures I have ever seen since the introduction of color TV.
The Comcast solution is to rent a similar box, that produces HD video,
and amazingly produces decent looking non-HD video for $10/month.
That's $120/year per TV set for what used to be free:
http://bgr.com/2013/10/16/comcast-digital-adapter-criticism/
https://www.google.com/search?q=comcast+dta&tbm=isch
Oddly, both types of DTA boxes use the same digital data for non-HD
stations, so it's not Comcast that's sending garbage video. It's the
DTA box.


I have an old cable ready TV that gets close to 100 of the analog chanels.
Just to see if it would work, I hooked up one of the off the air digital
converter boxes up to the cable an it did not pick up anything. Guess that
lets that out if our area goes to all digital.

A newer TV gets the analog and digital chanels off the cable. Then I have
one of the boxes hooked to the main TV.. If my wife could operate things, I
would go to something like Netflix.

The box does work off the air and I get about 30 chanels off the air with an
antenna out side the house.

On Tue, 3 Dec 2013 23:37:43 -0500, "Ralph Mowery"
wrote:

A newer TV gets the analog and digital chanels off the cable. Then I have
one of the boxes hooked to the main TV.. If my wife could operate things, I
would go to something like Netflix.

For Netflix, there are a variety of options. Computer, game box,
media player, tablet computers, and built into the TV. For your wife,
I suggest you try one of the Roku media players:
http://www.roku.com/products/compare
I have an older Roku 2 XS box and use it for Netflix. The remote
control has only a few buttons, so it's fairly easy to learn. The
difficult part is searching for shows to watch. I like to do that on
a computah, where I can type in the name of the program on a real
keyboard. You can plug in a keyboard into the Roku box, but that
might add too much complexity. When I find something worth watching,
I add it to my "favorites" list, which appears at the top of the
screen when selecting shows on Netflix. What's really nice about
Netflix is the total lack of commercials.

Last week, one of my customers bought an Xbox One gizmo at Costco.
Nifty system which can be voice controlled. All he has to do is say
"Xbox show Netflix" and it's up. However, within Netflix, he has to
use the included remote control. With the cable box, he can go
directly to his favorite channel. "Xbox show TCM" will bring up
Turner Classic Movies. If your wife can handle voice commands, it
might be an (expensive) option.

Marginally related RF drivel: One of my friends is avid DX'er. He
has all his media and computer gizmos interconnected via Wi-Fi because
Wi-Fi creates less RFI than ethernet. Then, he asks me to figure out
why his wi-fi is so slow. None of the computers caused problems, but
running Netflix in full 1080p was what was killing his wireless. My
solution was to sell him a dual band wireless router, and reserve the
5GHz band for video.

--
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 12/16/2013 2:43 AM, Jeff Liebermann wrote:
On Tue, 3 Dec 2013 23:37:43 -0500, "Ralph Mowery"
wrote:

A newer TV gets the analog and digital chanels off the cable. Then I have
one of the boxes hooked to the main TV.. If my wife could operate things, I
would go to something like Netflix.

For Netflix, there are a variety of options. Computer, game box,
media player, tablet computers, and built into the TV. For your wife,
I suggest you try one of the Roku media players:
http://www.roku.com/products/compare
I have an older Roku 2 XS box and use it for Netflix. The remote
control has only a few buttons, so it's fairly easy to learn. The
difficult part is searching for shows to watch. I like to do that on
a computah, where I can type in the name of the program on a real
keyboard. You can plug in a keyboard into the Roku box, but that
might add too much complexity. When I find something worth watching,
I add it to my "favorites" list, which appears at the top of the
screen when selecting shows on Netflix. What's really nice about
Netflix is the total lack of commercials.

Last week, one of my customers bought an Xbox One gizmo at Costco.
Nifty system which can be voice controlled. All he has to do is say
"Xbox show Netflix" and it's up. However, within Netflix, he has to
use the included remote control. With the cable box, he can go
directly to his favorite channel. "Xbox show TCM" will bring up
Turner Classic Movies. If your wife can handle voice commands, it
might be an (expensive) option.

Marginally related RF drivel: One of my friends is avid DX'er. He
has all his media and computer gizmos interconnected via Wi-Fi because
Wi-Fi creates less RFI than ethernet. Then, he asks me to figure out
why his wi-fi is so slow. None of the computers caused problems, but
running Netflix in full 1080p was what was killing his wireless. My
solution was to sell him a dual band wireless router, and reserve the
5GHz band for video.


Then he has a problem in his ethernet. Properly installed, ethernet
creates virtually no interference.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On Mon, 16 Dec 2013 07:46:16 -0500, Jerry Stuckle
wrote:

Then he has a problem in his ethernet. Properly installed, ethernet
creates virtually no interference.

Yes, that's the theory. If the cable isn't perfectly balanced, it
will become an antenna. Shielded ethernet adds additional
opportunities to radiate. Most of the RFI originates from ethernet
switches and routers.

One oddity are ethernet hubs. What goes in one port, goes out all the
other ports. With a switch, only data destined for a specific MAC
address on another port is passed. The problem is many older hubs
will send data to a port if a cable is inserted but not terminated.
They're not suppose to do that, but I've found a few old hubs that do
that. If you have an ethernet RFI problem, look into replacing hubs
with switches.

"Understanding and Eliminating RF Interference" by Jim Brown K9YC
http://www.audiosystemsgroup.com/RFIHamNCCC.pdf
Start reading at Page 20 for the ethernet radiation section.
Mo
http://www.audiosystemsgroup.com/publish.htm

This thread may also be of interest:
http://lists.contesting.com/_rfi/2008-11/msg00025.html

Note that 100baseT is quieter than 10baseT. With 100baseT, the data
is first 4B5B encoded at 125Mbits/sec. To reduce crosstalk, it is
then scrambled and MLT-3 encoded. The result is a 31.2MHz carrier and
a mess of sidebands. The necessary scrambling has the side effect of
reducing high power peaks, and evening out the power spectrum over a
wider frequency range, thus reducing the RFI power at any given
frequency. It's much the same idea as the "spread spectrum"
modulation of computer clocks, to spread the power over a wider
frequency range, to meet FCC Part 15 requirements. So, instead of a
carrier or birdie, you'll hear broadband noise, which I guess is more
tolerable.




--
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 12/16/2013 12:54 PM, Jeff Liebermann wrote:
On Mon, 16 Dec 2013 07:46:16 -0500, Jerry Stuckle
wrote:

Then he has a problem in his ethernet. Properly installed, ethernet
creates virtually no interference.

Yes, that's the theory. If the cable isn't perfectly balanced, it
will become an antenna. Shielded ethernet adds additional
opportunities to radiate. Most of the RFI originates from ethernet
switches and routers.


It's more than just theory. Over the years, we've installed hundreds of
ethernet systems, with little or no interference.

Shielded Category cable is much better - but you need to be careful. It
needs to be grounded at one end only (to prevent ground loops), and the
shield must carry through to the devices at the far end. The devices
must be shielded also, preferably in metal cases. Unfortunately, most
consumer-grade devices have plastic cases with little or no shielding
and do not connect to the shield. In cases like this, yes, the shield
can become a radiator. Commercial devices are better at this (but are a
lot more expensive).

One oddity are ethernet hubs. What goes in one port, goes out all the
other ports. With a switch, only data destined for a specific MAC
address on another port is passed. The problem is many older hubs
will send data to a port if a cable is inserted but not terminated.
They're not suppose to do that, but I've found a few old hubs that do
that. If you have an ethernet RFI problem, look into replacing hubs
with switches.


Again, that's the case with consumer-grade goods. Commercial grade are
much better at this.

"Understanding and Eliminating RF Interference" by Jim Brown K9YC
http://www.audiosystemsgroup.com/RFIHamNCCC.pdf
Start reading at Page 20 for the ethernet radiation section.
Mo
http://www.audiosystemsgroup.com/publish.htm


I think our expertise of doing this as a business for years in both
residential and commercial establishments qualifies us.

This thread may also be of interest:
http://lists.contesting.com/_rfi/2008-11/msg00025.html

Note that 100baseT is quieter than 10baseT. With 100baseT, the data
is first 4B5B encoded at 125Mbits/sec. To reduce crosstalk, it is
then scrambled and MLT-3 encoded. The result is a 31.2MHz carrier and
a mess of sidebands. The necessary scrambling has the side effect of
reducing high power peaks, and evening out the power spectrum over a
wider frequency range, thus reducing the RFI power at any given
frequency. It's much the same idea as the "spread spectrum"
modulation of computer clocks, to spread the power over a wider
frequency range, to meet FCC Part 15 requirements. So, instead of a
carrier or birdie, you'll hear broadband noise, which I guess is more
tolerable.


Again, it depends on the installation and equipment being used. But
10baseT is also old technology. 100baseT is more recent and solves a
lot of problems - both in radiation and susceptibility to interference
from external radiation.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On Sun, 15 Dec 2013 23:43:26 -0800 in rec.radio.amateur.antenna,
Jeff Liebermann wrote,
Marginally related RF drivel: One of my friends is avid DX'er. He
has all his media and computer gizmos interconnected via Wi-Fi because
Wi-Fi creates less RFI than ethernet.

Woah, how can that be? Would using shielded cat6 fix it?

On Mon, 16 Dec 2013 11:21:30 -0800, David Harmon
wrote:

On Sun, 15 Dec 2013 23:43:26 -0800 in rec.radio.amateur.antenna,
Jeff Liebermann wrote,
Marginally related RF drivel: One of my friends is avid DX'er. He
has all his media and computer gizmos interconnected via Wi-Fi because
Wi-Fi creates less RFI than ethernet.

Woah, how can that be? Would using shielded cat6 fix it?

I don't know. I don't have much experience with CAT6 STP as most of
my installations use CAT5e UTP cable (including for gigabit). It
might reduce radiation by shielding, or increase it if there's a
ground loop. In any case, the owner was not interested in wiring the
house, station, garage, antenna farm, front gate, home theater, etc
for ethernet. Wi-Fi did the job well enough and did not product RFI.

In retrospect, I probably should have spent more time finding the
exact sources of the HF interference. I did not make a systematic
check of the house, and did not check everything electrical in the
house. I didn't have the time as that would have taken days. Instead,
there was a large drop in RFI observed when the ethernet connected
devices were unplugged, so we went with that.


--
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 12/16/2013 10:44 PM, Jeff Liebermann wrote:
On Mon, 16 Dec 2013 11:21:30 -0800, David Harmon
wrote:

On Sun, 15 Dec 2013 23:43:26 -0800 in rec.radio.amateur.antenna,
Jeff Liebermann wrote,
Marginally related RF drivel: One of my friends is avid DX'er. He
has all his media and computer gizmos interconnected via Wi-Fi because
Wi-Fi creates less RFI than ethernet.

Woah, how can that be? Would using shielded cat6 fix it?

I don't know. I don't have much experience with CAT6 STP as most of
my installations use CAT5e UTP cable (including for gigabit). It
might reduce radiation by shielding, or increase it if there's a
ground loop. In any case, the owner was not interested in wiring the
house, station, garage, antenna farm, front gate, home theater, etc
for ethernet. Wi-Fi did the job well enough and did not product RFI.

In retrospect, I probably should have spent more time finding the
exact sources of the HF interference. I did not make a systematic
check of the house, and did not check everything electrical in the
house. I didn't have the time as that would have taken days. Instead,
there was a large drop in RFI observed when the ethernet connected
devices were unplugged, so we went with that.



Actually, if you have the right equipment, you can narrow it down in a
very short time. It seldom takes us more than an hour to find RFI
problems, and most can be done in 10-15 minutes. It never takes us
days, even in large installations.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.

==================