Antenna impossible take 2

[Hobiecat]

I tried to install an antenna in my attic. I installed a Wingegard 7968, along with a channel master 7777 amp. I was able to get the UHF stations reasonably well (meaning that the signal strength as measured by my TV was 70-88%). Of the two VHF stations, I can get 7.1 at 30%, and 13.1 was too low at 10%. The link to my last questions is
http://forum.tvfool.com/showthread.php?t=15732

So I have decided to install it in place of the Directv dish. The TVfool report is much better since this will be at 32 feet.
http://www.tvfool.com/?option=com_wr...8e0385ce749a50

The problem I still have are trees. I have attached a picture looking at the dish from the ground, looking towards 340, and as you can see there are large trees in the line of sight. Actually my house is surrounded by trees so there is no location where I can avoid trees except for 110 degrees.

Since I am a novice at this, I really need some help with the following:

1. What are the chances that if I extend the sat stand by 3 feet and install my antenna facing about 340 that I will get 13.1 and 7.1 clearly.
2. Should I place the antenna horizontal, of face it up (I assume 45+ degrees) towards the top of the trees.
3. Does the amp go outside on the antenna pole - is it environmentally safe.
4. The current sat wire is already grounded, if I add the amp near the antenna will the ground transfer through it and through a standard RG6 patch cord, or do I need to add something.
5. To ground the pole, what gauge wire do I need?

Of course if you see anything that I missed I would appreciate your input.

Thanks for all your help.

By the way I cancelled my directv, and am watching ESPN on sling with no issues.

[rabbit73]

Hello again, Hobiecat:

Thanks for the attic test results and the photo. The trees are pretty thick, but your signals are strong. I've seen other cases like your location work, but you will not know for sure until you test it.

What are the chances that if I extend the sat stand by 3 feet and install my antenna facing about 340 that I will get 13.1 and 7.1 clearly.

It's difficult to predict. The signals will be stronger because there will not be the attic loss, but as you said the trees are still there. There is the possibility that the 7777 preamp will be overloaded if the signals are a lot stronger. Channel Master says the 7777 should not be used in strong signal areas, but the tvfool report doesn't take into consideration trees or other buildings in the signal path.
http://www.channelmaster.com/TV_Ante..._p/cm-7777.htm

If you extend the sat stand by 3 feet it might not be stable enough for the 7698 antenna unless it has braces. You might need a different type of mount, like a tripod mount or a ground mounted mast that extends above the roof.

Should I place the antenna horizontal, of face it up (I assume 45+ degrees) towards the top of the trees.

If you did tilt it, 45 degrees would be too much, and there is no provision for tilting the front up with the 7698. Try it horizontal first. Tilting would be a custom job.

Does the amp go outside on the antenna pole - is it environmentally safe.

The 7777 and 7778 are designed to be mounted outside near the antenna with the power inserter and transformer inside.

4. The current sat wire is already grounded, if I add the amp near the antenna will the ground transfer through it and through a standard RG6 patch cord, or do I need to add something.
5. To ground the pole, what gauge wire do I need?

The coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC), the mast should also be grounded in a similar manner to drain any buildup of static charge, but the system will not survive a direct strike.



Some dish installers use a "piggyback" method of grounding the mount and coax shield, but it isn't according to code.

Satellite System Grounding
Part 2 - NEC Overview
Presented by Todd Humphrey
http://www.dbsinstall.com/diy/Grounding-2.asp

Todd Humphrey doesn't speak for the NFPA that publishes the NEC code, but he has some ideas that are helpful. The local electrical inspector has the final say if you are willing to get him involved. Some inspectors are more friendly than others; a local electrician could tell you.

It's usually OK to use the dish coax, but don't use other dish equipment like a multi switch or splitter, they might not be suitable.

[Hobiecat]

Rabbit73,

Thank you for all the good information.

The satellite dish mount has two braces on it. I ordered a 39 inch mount that bolts onto the satellite mount bracket. I will extend it enough to clear the roof top. I also plan to remove the dish, and LNB to reduce the weight on the mount. Do you think that is enough, or should I look at alternate methods.

I just plan to use the dish coax which is grounded to the house electrical ground wire. Can I run a parallel wire, connected to the mast, and ground it to the same electrical ground wire? Will the 7777 continue the ground to the antenna?

Appreciate all your help.

[rabbit73]

Do you think that is enough, or should I look at alternate methods.

I can't see how it is mounted to the roof, and I don't have enough experience to give you a reliable answer. Alternatives would be a tripod mount for the roof or a ground mounted mast fastened to the eave and side of the house with wall brackets. The tripod mount should have careful waterproofing where the screws penetrate the roof to prevent leaks; a roofers job.

Ant > preamp > coax > grounding > coax > power > TV
                      block    \         inserter
                                \
                                10 gauge wire > 
                                               \      
                             house electrical system ground
                                               / 
                         mast > 10 gauge wire >

Will the 7777 continue the ground to the antenna?

The coax shield between the antenna and the preamp will be a continuous ground connection down to the grounding block, which is connected to the house electrical system ground with 10 gauge wire. The boom clamp of the antenna will make contact with the mast, and the 10 gauge wire from the mast will be connected to the house electrical system ground.

Please keep in mind that I am not an electrician. The local electrical inspector, who is called the AHJ (authority having jurisdiction) has the final say.

[Tower Guy]

I'd predict preamp overload of the 7777 in your location. Remove the preamp from the circuit and retest. Note that unplugging the preamp power supply is not a useful test.