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Discussion in 'CB Antennas' started by NorthStar34, Aug 15, 2004.
I hope he doesn't plan on climbing to the top with the antenna in his hand. hehe
Hello 211 in the Mag, Bobby:
I have seen a lot of guys mount the antenna on a pipe or mast to get the antenna above the tree's so that the trees will not block the signals to the antenna. And again ground the Coax coming down the tree.
Jay in the Mojave
Hey all, i have never done this before but would like some input on this. I have a buddy who is going to get a Imax 2000 and wants to put it in or on top of a 80 (or better) pine tree. What all does he need to perfom this action to see max results. Thanks <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/grin.gif ALT=" >D">
He is going to put it at the top, no branches in the way if so they wil lbe cutt down, what do you need to get t oput it in the tree securly and what measures in every aspect needs to be taken step by step, he wants to do it right (im not going to do it, no way ). Will like a chimney mount work well with like a 4 foot pipe? What is the proper way to ground that sucker up there?
Any way you can think to mount the antenna should work as long as it's mechanically 'sound' (won't fall out of the tree). As for grounding, run an appropriately sized wire down the tree to your/his ground system. An approximately 100 foot ground cable will necessarily have to be larger than 'normal'. What size? Beats me, what does he have handy?
There's really not much attenuation from trees at HF...
Don't know if this will help or not but take a look. CDX-787 base The mount made it easy to push the antenna and mast up higher in the tree. Leave some slack in the u-bolts. It will allow you to push the mast up and then will lock against the mount when you repostition to make the next push. Once in place you can attach a ground wire and crank down on the u-bolts.
Hope this helps!
Magna Force 900
MR. COILY Single Coil/Wolf .64 ground plane
Every man is a damn fool for at least 5 minutes every day; wisdom consists in not exceeding the limit.
Chimney straps are not the best idea, as it may kill plant material above the strap. Think of a tree like your arm: If you put a strap too tight onto your arm and leave it there, it cuts off the circulation. It's a rough analogy, but you get the idea. If you want to use a mast, I would get a lightweight mast, attach the mast to a plate with some U-bolts, and then use 4 big lag screws and go directly to the trunk. The tree will heal around the lag screws and it should be pretty solid.
I agree with Moleculo there, about NOT using Chimney Straps on a tree.
I have used rope and whet ever was laying around to that the tree could grow while holding up the mast.
The coax needs to be connected to a ground rod as it comes down to the ground to attenuate static, and offer some protection to Lightning. Or a first class installation, have a Lightning Arrestor connected to the Groung Rod, having the coax connected to the Lightning Arrestor.
Heres a web site for a Alah Delta Surge Protector:
Jay in the Mojave
That would be worh a few photos, that would be a neat way of doing it all right. Got a web site site showing how thats done?????
I have seen Commerical Broadcast Towers use a very large Toroid Core that had the windings wound to make a very high voltage breakdown resistance type of Isolation Transformer, allowing the 115 Volts or 220 Volts to be physillay isolated from the tower, so that it woun't de-tune the tower when feeding the tower with the voltages to run the lights at night. Pretty sneaky!
The high reactance coil would have to be designed to take a lot of current and need a place to mount the input and output connectors. Maybe a Copper tubing coil mounted in a 4 or 6 inch diameter PVC Pipe would do? Then we coulkd even tune the coil with screw driver motor and variable capacator as a tunable filter. Oh Yeah.
The Dispencing of Beer would get ya on the front of 73 Magazine no dought, but hot QST!.....................
Jay in the Mojave
Actually the coil does not have to made of very large wire at all.16-18 Ga. is fine.The idea is to provide a path to ground for the static that tries to build up before a strike occurs.I have three AM broadcast TX's and they all have a "static drain choke". They are about a 16-18 inches in length and about 2 or 2 1/2 inches diameter and are close wound with enamel coated 16 ga. wire and are connected across the antenna feedpoint to ground.It offers a very high impedance to the broadcast band but a dead short ( or very close) at DC.The idea is to help bleed of the static and if no static charge is present then no strike occurs.I have taken direct hits during a severe storm but the static drain choke has never failed.That is because they offer a relativly high impedance to the complex charge of a lightning strike and should never be used alone as protection.They are to drain the buildup of a charge but sometimes it just can't do it quick enough and then you need other protection.I would use one along with a spark gap to ground on the antenna side of it.They sure help if you have wind generated static noise in a dry location.
You could also make sure to leave a few turns of coax at the base of the tree and connect the shiel to ground at the bottom.This introduces extra inductance to impede the lightning and shunts it too ground.
Garth 9VE01 PE993 CDX993 Learn from others mistakes.You can not live long enough to make them all yourself.</p>Edited by: <A HREF=http://p067.ezboard.com/bworldwidecbradioclub.showUserPublicProfile?gid=qrn>QRN</A> at: 8/17/04 6:00 pm