Tripod mount on roof plan

[cphilip]

Also give me your feeling on this idea I have for the Antenna mounting.

Up on the roof now I have a tripod that currently holds an unused Satellite Internet dish. It was put up there about a year or so back. These dishes are fairly large (perhaps about three times the size of a normal satellite TV service one) and so the tripod is quite stout. In fact, from looking at some available tripods that are purpose built for verticles I find its a good deal heavier and larger (and nicer) than most I am finding. Plus its already there. And its already grounded to its own Ground rod line and all there already.

My plan is to remove the dish from the tripod (since it's no longer needed, anyone want a nice working Starband set up?) and mount the Antron 99 to that tripod. The upright pipe from that tripod is a bit larger diameter than typicial antenna pole stuff. But I have a nice new piece of TV antenna rod about 5-6 feet long. And I would estimate that the tripod stands about 2-3 feet off the roof surface as it is. So I was going to clamp (actually dril and bolt through several times) this extra length of smaller diameter pole into the tripod neck and then mount the A99 to that small pole a bit higher up. So it would be about 7 feet off the deck and perhaps 3 feet about the roofs peak where the bottom of the A99 would start. And then of course it goes up 18 more feet from there.

Now the roof is two story at the back and one story to the front of the house. So overall height of the antenna is hard to calculate. It would be at least 30 feet to the bottom measured from the back yard. But perhaps only 20 or so feet measured from the ground up from the front yard perspective. Best I can do I think.

Then my clever scheme is to put one of these lightning arrestors (pictured below) on but I am not sure where. I would assume at the junction of the Antenna to the Coax running down to the house and bridge the Ground to it?

then this will go on down to the shop and into the shop and be attached to a one into two antenna switch. Then the radio and scanner hooked to that switch... and so on...

So its like this:

A99 - grounded pole - tripod - Lightning arrestor - coax - switch - scanner (on switch position 2) antenna tuner/meters/radio (on switch position 1)

What say you?

 

[Moleculo]

I can't quite tell from the pic, but make sure the lightning arrestor is a 50 ohm unit. Usually, the arrestor has a connection that you connect to ground. You put the arrestor just outside the house, before the coax runs inside and attach it to a suitable ground. Unless I missed something, the T connector needs to be eliminated. Other than that, your setup should work fine. BTW, all the grounds (tripod, lightning arrestor, etc.) should be attached to the main house ground. I'm a culprit of not doing this, but don't follow my example on that....

 

[cphilip]

Hmmm... specs don't mention specificaly 50 ohms... but does specify its for typical radio installation. And specificaly Coax with PL-259 connectors. The brass threaded end with nuts (heh.. I said nuts) is where the ground attatches. This has a gas filled chamber off to the side. So the T is for the coax to pass through.

Take a look at this and tell me what you think:

http://www.spiromfg.com/parts.htm

(in case thats not a direct link its under "Parts and accessories"


And I am curious why it would be that the ground would need to go to the house ground. Because the current dish up there has its own ground rod driven in seperately to the house ground. And mainly that was done to give that its own path from the roof and not represent a place for feedback to the houses box. I would have thought that was better but what do I know...

I had planned on running it all to its own ground... but now you got me rethinking that. The issue is that its going to be on the top of one house but the actual termination point is to the shop which is a seperate structure about 20 or so feet away. Metal clad structure at that. But with wood framing and wood floor and floor joices.

 

[Beetle]

Lightning arrestors of this type don't come in different impedances. Connect any kind of coax via PL-259s and go.

The grounds - all of them - have to be bonded together at the safety ground for the house, which is usually located near the utility entry to the building. Having one ground rod for an antenna fifty feet from the safety ground, another ground rod for a tower 75 feet from there and so forth without bonding them securely together is a recipe for disaster in lightning storms, and also a violation of the NEC.

Very few areas have conditions in which a single 8-foot ground rod will have less than several ohms of resistance measured to the safety ground (which is "the" reference point). It depends on soil chemistry, soil dampness and many other factors.

Be safe. Do it right. Get a copy of the NEC (it might be available online) and follow the requirements for grounding to the letter. If the worst happens, your insurance company will be happy with you if you can show them that your grounding system was up to code. Otherwise... :evil:

 

[cphilip]

So...if I am reading what your saying correctly, I should bond this existing seperate ground to the house ground? And then use it. Since I am no more than say 40 feet to the outbuilding that the coax is going to then that should be sufficient? But as it is now the seperate grounding rod is not attached to the structure that the antenna is on but needs to be?

Our area is damp solid Clay. The installer of the original Sattelite dish is an FCC approved installer. But that doesn't mean he knows Building and Electrical codes all that well I would suspect. He should at least know these things... but... one wonders. I will also check the Southern Building code. Bonding these two together would not be difficult. They exist about 20 or so feet from each other.

Thanks Beetle. I will do some searching to see if I can find that NEC stuff. Sound interesting yet boring...

 

[Beetle]

"...interesting yet boring."

WELL SAID!

 

[714]

Dish Ground

There's a good chance the Dish Ground Rod is only a Four Footer. Probaly OK if you tie it to the House Elect. Ground.
Is the Ground wire at least #4 or 6 as it should be.
Doug

 

[cphilip]

Very likely something like that. They rarely go to much trouble. However I have also seen them do that on the house ground too if they can get away with it and no one is watching. I think I will tie it in. Since I can run it along the wall in a shallow trench to the house ground it should not be too much trouble. I also need to upsize the wire coming from the Lightning arrestor to that ground as well. Its too small the one they got running from the (existing) coax. So might as well just get a few extra feet and do that too.

I went up on the roof this morning and removed the dish. And plan to go back up tomorrow morning and install the up pipe and antenna. And do the first drop to the location just above the first ground rod. Thats where I am going to tie in the Lightning arrestor. And then that goes to ground and the second run of Coax to the shed about 15 feet away. Unfortunately the lightning arrestor is not here yet so I cannot complete it. But I can test it and then take that connection back apart until it does arrive. Disconnect everthing.

The Radio arrived today so all I could do was power test it with a magnet mount antenna and a long piece of Coax that I had laying around. Dared not key it up with that Antenna though... so just checked to see if it powered up and it does nicely. Even got some trucker talk coming in on AM 19 from the interstate about five miles away with that little thing as soon as it powered up. I have a rythmic pulsing noise coming in on it and bumping the signal meter just a tad. But did not want to run it long enough to start trying to dial that out and not certain it might not clear up some with the better antenna set up. I did try turning everything off in the shop and none of those seemed to be the culprit. Although after it was all done I realized I had never turned off the lights. Although thats not the noise I don't think. Its not a buzz... its a bump bump bump.... rythmic and steady. Just a bounce of the signal needle. Going to wait till I get the Antenna up and see where I need to go with that.

And until I get that lightning arrestor on and those two tied together I am going to have to disconnect regularly. Althought the switch I ordered has a dead spot and that will be in there eventualy also. But its not here either.

 

[cphilip]

So far.... so good....

 

[Highlander_821]

Looks good...

I don't know if you have experienced global communications on 11 meters yet, but you picked a good time to get set up. The sunspots are coming, the last solar peak saw me talking to South Africa from the mobile with just 15 watts into a Wilson 1000. Europe almost every morning and Australia and its environs nearly every evening!

 

[cphilip]

Well that's certainly a blessing.

I still got some stuff to do. Some of it worries me a bit. For one thing the Lightning arrestor has not arrived. And so for now I just have the two coax cables that were up there for the Sattelite internet dish bonded to the tripod and left there as they go down and are bridged to ground already. Which I intend to remove when the Lightning arrestor comes. Right now I have that first drop of radio coax just directly joined to the second run that goes into the shack. Right where the lightning arrestor should be. I have that strapped to the bridge of the other two coax's for now. Makes me a bit nervous as there is a chance of rain storms coming Tuesday. I plan to disconnect everything but still... would feel better completing the thing before then. I have to go Monday and get some 6 guage wire and clamps. So I will be ready... and plan on bonding this ground rod to the main then. But until I get that arrestor bonded in to the group I am going to not rest easy. My hope is that it will be delivered Monday.

I have actually changed my scheme from earlier due to input from here.

Now it goes like this:

A99 - Tripod - Coax (20 feet) - Lightning arrestor (bonded to ground rod that is bonded to house ground) - Coax (75 feet and into shack) - 2 into one switch - Scanner (on switch position 2) antenna tuner/meters/radio (on switch position 1)

 

[Toll_Free]

So...if I am reading what your saying correctly, I should bond this existing seperate ground to the house ground? And then use it. Since I am no more than say 40 feet to the outbuilding that the coax is going to then that should be sufficient? But as it is now the seperate grounding rod is not attached to the structure that the antenna is on but needs to be?

Our area is damp solid Clay. The installer of the original Sattelite dish is an FCC approved installer. But that doesn't mean he knows Building and Electrical codes all that well I would suspect. He should at least know these things... but... one wonders. I will also check the Southern Building code. Bonding these two together would not be difficult. They exist about 20 or so feet from each other.

Thanks Beetle. I will do some searching to see if I can find that NEC stuff. Sound interesting yet boring...

Your installer is a liar. The FCC doesn't certify installers.

You want to research the NEC codes for and the codes for YOUR STATE / municipality. Every state has their own laws / codes / etc. The national guide is a "guide" for them to go by (it sets up the loosest laws, states can be more strict).

But, I do agree with what you where told. All grounds should be bonded to the house ground.

You don't really want to bond grounds together.... You optimally should have it set up where your service entrance and tower are located near each other. When you start bonding grounds, how much current do you think that "bonding wire" will carry between the rods?

I agree with you, the code, and common sense. I ground my tower at the base, ground the antenna to the same ground, and bond my grounds together.

Here's something else for your "Einstein FCC Cert. Installer".

Don't you think the coaxial braid on the cable will carry "bad things" down your coax and into your house if lightning hits? I mean, that 12 gauge piece of aluminum wire is going to carry more current than 2 pieces of coaxial cable braid, aluminum foil, etc?

Sheesh. What some pass off for knowlege.... However!!!

Yeah, if you don't want that dish, and it's still around when the tower arrives, I'll take it off your hands. I want to try to set up an 802.11 link across the Monterey Bay from where I live. I think it's doable, but I'll HAVE to use a parabolic.

--Toll_Free

 

[Toll_Free]

1. Lightning arrestors functionality has been questioned. Some swear by them, others swear at them.
2. I have rebuilt a Tram D201A that was "protected" by an arrestor.
3. I've been into radio > 20 years. I've never used an arrestor
4. I lived in Texas and Florida... And in Oklahoma. All 3 states are known for electrical storms
5. I've run antennas > 100 feet off the ground
6. Use those unused coax cables dish left for your ground leads to the cb antenna. Make them both the same length, then lop around 4 inches off one. Tie both of the OUTER conductors together. Now, tie this to your antenna earth side. NOW, run both of the other sides, in the shortest manner possible, to the service ground for the house.

I also like the idea you had, of trenching some wire to the service entrance.

I wouldn't do it near the house, though. The whole idea of earthing is to get the lightning to the earth, and away from the castle.... It would work, but don't do it near any rooms you inhabit... EVER.

7. I doubt you will ever get enough isolation from the radio to the scanner to keep from blowing the front end of the scanner, unless you get a "shorting" type switch... One that grounds the other leads. this is usually an antenna type switch, and usually the remote styles. See what you got, first. Your better bet would be to eliminate your arrestor, your switches, all that crap, and just run a piece of coax from the radio to the antenna. Be done with it. Then run to radio shack and get a "back of scanner" antenna. I use one. I listen to things > 100 mile radius.


Hope this helps. Lots of people offered advice, and although your doing it textbook, you can NOT use the switch (better idea), not use the arrestor (and not have to stuff your coax into (I LOVE this one... . a mayonnaise jar FILLED with water)) and get by and be safe. You can also use a 10 dollar RS antenna on your scanner and be done with it.

--Toll_Free

 

[cphilip]

Your installer is a liar. The FCC doesn't certify installers.



I believe the term I used was "approved"... but... Ok... well....lets get technical then. I am guilty there of abreviation. The FCC does indeed REQUIRE the installers of these to be HNS certified. So what I ment was that this is the Certification that is acceptable to the FCC. But didn't mean to get into that in depth. But these are the big higher power two way Sattelites. Not the typical TV stuff. It is a condition of license to these couple of companies that they will install only using HNS certified technicians. Huges and such have these conditions for the installation of Sattelite internet dishes. So my bad... I glossed over it too much. I forgot I was amongst technophiles! But... heck... I thought he was lying too. When I bought the equipment. But I did some research and found out he was not. Unfortunately the FCC did make it a condition of license and the certification they accept is HNS. And so they are FCC "Approved " as long as they are certified by the HNS.

You want to research the NEC codes for and the codes for YOUR STATE / municipality. Every state has their own laws / codes / etc. The national guide is a "guide" for them to go by (it sets up the loosest laws, states can be more strict).


Yes. Would be the Southern building code. And could indeed be different. So I will check that out.


Yeah, if you don't want that dish, and it's still around when the tower arrives, I'll take it off your hands. I want to try to set up an 802.11 link across the Monterey Bay from where I live. I think it's doable, but I'll HAVE to use a parabolic.


I got no use for it. And I have the working modem as well if anyone is interested. They are like 300 bucks alone.

Phil

 

[cphilip]

1. Lightning arrestors functionality has been questioned. Some swear by them, others swear at them.

I don't trust em either. However if its transient and not direct, it might work. Main thing I see in the latest plan is that the first section of coax sort of becomes sacrificial. If it makes it to the lightning arrestor its probably toasted. But that is then where the main copper 4 gauge is attached down to ground. So the hope there is that it might mostly go to ground... and or deminish the amount that can make it trough to the next stage. I doubt a direct strike is going to be protected by anything more than Insurance policy.

2. I have rebuilt a Tram D201A that was "protected" by an arrestor.
3. I've been into radio > 20 years. I've never used an arrestor
4. I lived in Texas and Florida... And in Oklahoma. All 3 states are known for electrical storms
5. I've run antennas > 100 feet off the ground
6. Use those unused coax cables dish left for your ground leads to the cb antenna. Make them both the same length, then lop around 4 inches off one. Tie both of the OUTER conductors together. Now, tie this to your antenna earth side. NOW, run both of the other sides, in the shortest manner possible, to the service ground for the house.

Thats actually reassuring! Hope I do as well.

I also like the idea you had, of trenching some wire to the service entrance.

I wouldn't do it near the house, though. The whole idea of earthing is to get the lightning to the earth, and away from the castle.... It would work, but don't do it near any rooms you inhabit... EVER.

Well it would have to be from the edge of the house TO the service entrance of the Shop/Shed/Shack... Or would it be better to go overhead there instead if its only 20 - 30 feet between them?

7. I doubt you will ever get enough isolation from the radio to the scanner to keep from blowing the front end of the scanner, unless you get a "shorting" type switch... One that grounds the other leads. this is usually an antenna type switch, and usually the remote styles. See what you got, first. Your better bet would be to eliminate your arrestor, your switches, all that crap, and just run a piece of coax from the radio to the antenna. Be done with it. Then run to radio shack and get a "back of scanner" antenna. I use one. I listen to things > 100 mile radius.


Hope this helps. Lots of people offered advice, and although your doing it textbook, you can NOT use the switch (better idea), not use the arrestor (and not have to stuff your coax into (I LOVE this one... . a mayonnaise jar FILLED with water) and get by and be safe. You can also use a 10 dollar RS antenna on your scanner and be done with it.

Dukes or Helmans?