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alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1

1 recommendation

[Roofing] My weekend project - OTA Antenna

more than 18 months after this thread, I finally got around to doing something.

The antenna



It's a CM4228HD with a CM3412 drop amp that I use instead of a pre-amp because I don't see why not (Both same NF and gain).

The LOS



I get EVERYTHING in listed here that's green and yellow (Everything LOS). Click on "Pending" considering all the stations in pending are now functional.
EXCEPT Fox and ABC. The TV tuner detected Fox's channel but when I tune to it, I get no signal.

It's pointing towards the US stations (The ones in the 143 degree section)

I doubt that any adjustment will suddenly get me a usable signal. Fox uses a transmitter that's 1/10th the power of CBC/NBC, etc, and ABC use 1/50th the power of CBC/NBC etc.

The whole setup is grounded through a 10AWG copper line going to a ground rod that was originally installed for an antenna that used to be there before, and then bonded to the house ground (copper pipe).

Not bad, I worried so much 18 months ago about getting nothing, and I pretty much get everything (Except for Fox and ABC which turns out are problem channels for everyone in my region).


cowboyro
Premium
join:2000-10-11
Shelton, CT
said by alkizmo:

The whole setup is grounded through a 10AWG copper line

A direct lightning strike will turn it into vapors.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

1 recommendation

A direct lightning strike will turn most anything to vapors. There is NO PROTECTION that's cost effective or will offer protection to a residential dwelling. All the Blacks around here have Lightning rods and ground wires running everywhere connecting them.

I have the same antenna and while lightning has made toast of my Directv dish several times the antenna is ok.


shdesigns
Powered By Infinite Improbabilty Drive
Premium
join:2000-12-01
Stone Mountain, GA
Reviews:
·EarthLink
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·Atlantic Nexus
reply to alkizmo
Looks good.

Funny, take the trees you have and make them 1/4 mile thick with houses in the middle and also higher elevation and you have what i have.

It does not matter what direction I point the antenna, I get the same signal. Any wind and I get multipath dropouts.

Good to hear yours works.
--
Scott Henion

Embedded Systems Consultant,
SHDesigns home - DIY Welder

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
reply to alkizmo
said by alkizmo:

It's pointing towards the US stations (The ones in the 143 degree section)

I doubt that any adjustment will suddenly get me a usable signal. Fox uses a transmitter that's 1/10th the power of CBC/NBC, etc, and ABC use 1/50th the power of CBC/NBC etc.

If you really want to pick up ABC, you could try a very high gain yagi optimized for CH13 pointed at 143 deg.

You can aim the current antenna towards 99 deg to have much higher signal strength for most channels.

resare

join:2012-11-07
Greenfield Park, QC
Reviews:
·ELECTRONICBOX
reply to alkizmo
Im in longueuil with similar antenna (the 2-panel version) with an amp, and get the same results (no fox, no abc)

With 2nd panel i get all mtl stations as well. 21 channels free , nice !!

Never regretted the 200$ to install vs. The monthly fee of cable tv (50$+/month)


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1

1 edit

1 recommendation

said by shdesigns:

It does not matter what direction I point the antenna, I get the same signal. Any wind and I get multipath dropouts.

I'm fortunate to either have stations within 12 miles, or that the far away stations have 450kW transmitters.

There are several layers of trees further down the path, but the transmitters seem to be well equipped to dig through.

Multipath is horrible on Fox44 because of its weak transmitter not digging through.

said by lutful:

You can aim the current antenna towards 99 deg to have much higher signal strength for most channels.

Ok, I will bite, why?
All the Montreal stations are 80%-100%, why would I want to turn away from the US transmitters?

said by resare:

Im in longueuil with similar antenna (the 2-panel version) with an amp, and get the same results (no fox, no abc)

With 2nd panel i get all mtl stations as well. 21 channels free , nice !!

Never regretted the 200$ to install vs. The monthly fee of cable tv (50$+/month)

I probably would get Fox if it wasn't for the trees. I will find out this winter when all the leaves fell off the trees.

I mostly wanted to get CBC and City Montreal for hockey games.
Global TV plays a lot of what Fox44 plays.

edit - It's tropo time! I'm picking up Fox clear as day.

iknow_t

join:2012-05-03
reply to Jack_in_VA
said by Jack_in_VA:

A direct lightning strike will turn most anything to vapors. There is NO PROTECTION that's cost effective or will offer protection to a residential dwelling. All the Blacks around here have Lightning rods and ground wires running everywhere connecting them.

I have the same antenna and while lightning has made toast of my Directv dish several times the antenna is ok.

what are the Whites doing to protect theirs?? surely, a proper Lightning rod system will attract the Lightning and send it safely to ground.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
reply to alkizmo
said by alkizmo:

said by lutful:

You can aim the current antenna towards 99 deg to have much higher signal strength for most channels.

Ok, I will bite, why?

That was conditional on a separate high gain Yagi towards 143 deg. You did not mention the strong signal strengths from 91 deg direction in original post.


Boooost

@76.65.143.x
reply to alkizmo
Boooost's to-do list today (after I tour Hydro-Quebec's generating station) - Drive around Pierrefonds looking for the house with the shiny, new antenna, and say "Hi" to alkizmo.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by lutful:

That was conditional on a separate high gain Yagi towards 143 deg. You did not mention the strong signal strengths from 91 deg direction in original post.

I guess I didn't make that clear.
Yeah there is no point to combine two antennas for different directions.
If anything, I would need to gang a second CM4228HD to try and increase the gain to catch Fox.

Last night I had a pretty darn perfect reception, now I don't anymore, it's all about the troposphere for some reason.

The winter time will tell me if it's all because of the trees, however I plan to return on my roof this weekend to play with the alignment. I bought a nice featherlite ladder to make the climb easier.

said by Boooost :

Boooost's to-do list today (after I tour Hydro-Quebec's generating station) - Drive around Pierrefonds looking for the house with the shiny, new antenna, and say "Hi" to alkizmo.

Unfortunately, I gave so much info about my house on this forum that anyone who knows the west island can pretty much pinpoint my house.

Don't come knockin' because my wife might think you're a salesman, and she's angry Chinese.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

1 edit
reply to iknow_t
said by iknow_t:

said by Jack_in_VA:

A direct lightning strike will turn most anything to vapors. There is NO PROTECTION that's cost effective or will offer protection to a residential dwelling. All the Blacks around here have Lightning rods and ground wires running everywhere connecting them.

I have the same antenna and while lightning has made toast of my Directv dish several times the antenna is ok.

what are the Whites doing to protect theirs?? surely, a proper Lightning rod system will attract the Lightning and send it safely to ground.

Nothing. I've never seen a lightning protection system on any houses in this area other than the older Blacks.


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to Jack_in_VA
said by Jack_in_VA:

A direct lightning strike will turn most anything to vapors. There is NO PROTECTION that's cost effective or will offer protection to a residential dwelling.

You couldn't be further away from truth.
Virtually all houses in Europe have lightning rods, and they work. Of course the grounding "wire" isn't a wire, it's more of a thick steel band.
The current of a strike is typically in the 10,000A range and extremely rarely exceeds 100,000A. The strike lasts no more than 200ms. It is fairly simple to calculate the minimum thickness of a wire that will dissipate lower heat than what it takes for it to overheat.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
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Big difference we're not in Europe. No need to cite anything there.

I am familiar with lightning protection designed by companies with engineers with the expertise. Buildings with different height air terminals and yes they are connected with "round" bare aluminum cable tied to the building grounding system.


cowboyro
Premium
join:2000-10-11
Shelton, CT
said by Jack_in_VA:

Big difference we're not in Europe. No need to cite anything there.

The laws of physics are the same. The thicker the cable the lower the heat dissipation and the higher the thermal mass the lower the temperature gain.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by cowboyro:

The laws of physics are the same. The thicker the cable the lower the heat dissipation and the higher the thermal mass the lower the temperature gain.

I think he was debating on whether the grounding wire has to be hooked up to rods or just the building grounding system.

In my case, it is hooked up to the house's grounding system, which is the cold water copper pipe.

The OLD antenna has a bare round/solid aluminum cable that only went to a grounding rod. That cable was unflexible, thus uglily protruding from the cable path. I replaced it with braided 10AWG copper that clamps THROUGH the original ground rod and continues inside the house to the copper pipe


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to cowboyro
said by cowboyro:

said by Jack_in_VA:

Big difference we're not in Europe. No need to cite anything there.

The laws of physics are the same. The thicker the cable the lower the heat dissipation and the higher the thermal mass the lower the temperature gain.

Do you have a lightning protection system on your home?

iknow_t

join:2012-05-03
reply to alkizmo
said by alkizmo:

said by cowboyro:

The laws of physics are the same. The thicker the cable the lower the heat dissipation and the higher the thermal mass the lower the temperature gain.

I think he was debating on whether the grounding wire has to be hooked up to rods or just the building grounding system.

In my case, it is hooked up to the house's grounding system, which is the cold water copper pipe.

The OLD antenna has a bare round/solid aluminum cable that only went to a grounding rod. That cable was unflexible, thus uglily protruding from the cable path. I replaced it with braided 10AWG copper that clamps THROUGH the original ground rod and continues inside the house to the copper pipe

that's going to look like an open circuit to the 1 GHZ frequency of a lightning strike though..


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by iknow_t:

that's going to look like an open circuit to the 1 GHZ frequency of a lightning strike though..

What am I supposed to do? A ground rod perimeter surrounding my house all bonded with 6AWG?


tschmidt
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join:2000-11-12
Milford, NH
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1 edit
Welcome to the ranks of OTA TV viewing. I'd much rather spend a few hundred dollars every few decades than $100 a month for the privilege of watching commercials.

said by alkizmo:

What am I supposed to do? A ground rod perimeter surrounding my house all bonded with 6AWG?

Agree with iknow_t See Profile the lower the impedance the better. The goal is to minimize voltage differences between metallic objects in the building.

Assuming the antenna is some distance away from building ground then a driven ground rod at the antenna with antenna, ground electrode and building ground bonded with 6AWG. The coax should pass through a grounding block where is enters the building and a gas tube coaxial surge suppressor at the ground block can't hurt.

/tom


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to alkizmo
said by alkizmo:

In my case, it is hooked up to the house's grounding system, which is the cold water copper pipe.

The OLD antenna has a bare round/solid aluminum cable that only went to a grounding rod. That cable was unflexible, thus uglily protruding from the cable path. I replaced it with braided 10AWG copper that clamps THROUGH the original ground rod and continues inside the house to the copper pipe

(1)Hooking it to the cold water pipe is not sufficient for lightning protection.

(2) The ugly round/solid aluminum wire hooked to a ground rod that was on the old antenna was probably acceptable since apparently you don't have a driven ground rod for your electrical service.

(3) Running it inside the house is very dangerous since a strike will be directed inside the house. A strike current will heat that #10 up to red hot and cause a fire inside the house.

telco_mtl

join:2012-01-06
said by Jack_in_VA:

said by alkizmo:

In my case, it is hooked up to the house's grounding system, which is the cold water copper pipe.

The OLD antenna has a bare round/solid aluminum cable that only went to a grounding rod. That cable was unflexible, thus uglily protruding from the cable path. I replaced it with braided 10AWG copper that clamps THROUGH the original ground rod and continues inside the house to the copper pipe

(1)Hooking it to the cold water pipe is not sufficient for lightning protection.

(2) The ugly round/solid aluminum wire hooked to a ground rod that was on the old antenna was probably acceptable since apparently you don't have a driven ground rod for your electrical service.

(3) Running it inside the house is very dangerous since a strike will be directed inside the house. A strike current will heat that #10 up to red hot and cause a fire inside the house.

I have to concur my neighbors look tv mast (look was a microwave based TV service here in canada) fell on a power line (nothing like lightning i know) and i will say they were more than thankful that the grouding on the mast was still there from when it was a mast for the regular tv.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to Jack_in_VA
said by tschmidt:

Assuming the antenna is some distance away from building ground then a driven ground rod at the antenna with antenna

Ok, the ground rod is already there.

said by tschmidt:

ground electrode and building ground bonded with 6AWG.

said by Jack_in_VA:

(3) Running it inside the house is very dangerous since a strike will be directed inside the house. A strike current will heat that #10 up to red hot and cause a fire inside the house.

You both say opposite things.
The ground electrode/rod cannot be bonded to the building ground unless the copper wire goes inside the house.
Or is the only acceptable way is to use AWG6 instead of 10AWG?

Can I use 10AWG from atenna to rod, and 6AWG from rod to copper pipe? (I still have enough 6AWG left over to do rod to pipe)

said by tschmidt:

The coax should pass through a grounding block where is enters the building and a gas tube coaxial surge suppressor at the ground block can't hurt.

What should the block be grounded to?

said by Jack_in_VA:

(1)Hooking it to the cold water pipe is not sufficient for lightning protection.

But what is the acceptable setup for residential antennas?

said by Jack_in_VA:

(2) The ugly round/solid aluminum wire hooked to a ground rod that was on the old antenna was probably acceptable since apparently you don't have a driven ground rod for your electrical service.

So you're saying that the antenna should be grounded to the rod, as long as the rod isn't bonded to the house ground?


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
The ground rod should be tied to the service ground with a #6 copper conductor.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by Jack_in_VA:

The ground rod should be tied to the service ground with a #6 copper conductor.

Ok, so if my only modification is to change the 10AWG going from the rod to my pipe with 6AWG, would I be fine?


tschmidt
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Milford, NH
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reply to alkizmo
said by alkizmo:

You both say opposite things.
The ground electrode/rod cannot be bonded to the building ground unless the copper wire goes inside the house.
Or is the only acceptable way is to use AWG6 instead of 10AWG?

In the US the NEC (I assume there is a similar requirement in Canada) requires the antenna be bonded to building ground with 6AWG copper or larger. That is large enough to prevent it from being vaporized as Jack_in_VA See Profile posted.

If the antenna is any distance away from the main building ground the ground rod will dump most of the energy into the earth, minimizing how much flows in the bonding conductor. The ground rod must be bonded to antenna and building ground system.

said by alkizmo:

What should the block be grounded to?

The coax grounding fitting should be connected to the grounding conductor near where the coax entered the house.

Thinking about a water analogy might make it easier to visualize. You are trying to make it as easy as possible for water to get to Earth.

/tom

iknow_t

join:2012-05-03
reply to alkizmo
said by alkizmo:

said by Jack_in_VA:

The ground rod should be tied to the service ground with a #6 copper conductor.

Ok, so if my only modification is to change the 10AWG going from the rod to my pipe with 6AWG, would I be fine?

you'd be much better off.. safer would be the word..

resare

join:2012-11-07
Greenfield Park, QC
reply to alkizmo
Yes, you will get better signal in the Winter.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to iknow_t
said by tschmidt:

If the antenna is any distance away from the main building ground the ground rod will dump most of the energy into the earth, minimizing how much flows in the bonding conductor. The ground rod must be bonded to antenna and building ground system.

The antenna is on my roof, so it's not any distance of the building. The rod is about 2 feet from my exterior wall. I guess I may as well use the rod since it's already there though.

said by tschmidt:

The coax grounding fitting should be connected to the grounding conductor near where the coax entered the house.

I'm just having trouble seeing a coax grounding block being able to clamp a 6AWG stranded copper wire. Usually those things are made to clamp onto line drop masts.

said by iknow_t:

you'd be much better off.. safer would be the word..

The question was whether the 10AWG from antenna to rod also needed to be replaced.
I figure that wire can turn red hot without causing problems since it's outside.


tschmidt
Premium,MVM
join:2000-11-12
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reply to alkizmo
said by alkizmo:

my only modification is to change the 10AWG going from the rod to my pipe with 6AWG, would I be fine?

This is where technical and legalese converge.

From an engineering standpoint connecting the antenna bonding conductor to copper cold water pipe is fine. Having larger surface area the pipe has a lower impedance then 6 AWG cable.

However: to be legally compliant the 6 AWG bonding conductor must run all the way to the building ground system. The reason is concern that in the future someone will replace a section of copper water pipe with plastic nullifying the ground.

/tom