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I recently purchased an Alpha Delta DX-EE HF dipole antenna for my base station. I read on the Alpha Delta site that the antenna should be mounted (ideally) at 25ft or higher. This being my first experience with erecting antenna structures, I'm a little unsure how to proceed safely. I'm planning to mount the antenna in an inverted-v on my roof. The problem I'm having is in how to get a 25ft mast safely mounted on the roof of my house.I looked into getting a tripod (the kind seen holding TV yagi antennas) which would straddle the peak of the roof and hold my 25ft mast. But then, I don't have any idea how tall an antenna needs to be before it requires guy wires. Does anyone have any experience with this?73,Marc - W7AYU
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Just my opinion here…You'll definitely need guy wires. Depending on the mast you use you may not have a lot of choice where to put the mast ring that the guy wires attach to in which case you'll have to adjust where and how you attach the antenna.The primary concern isn't as much your antenna, though it is a concern, but rather the angular forces that the base of the mast will be subject to by the load from wind blowing the antenna and mast. The last thing you want is a damaged roof!This is the type of base I have used in the past: http://www.shopjubilee.net/itm00400.htmMake sure you tie it into the trusses if possible or add some boards across two trusses to anchor into so you aren't counting on the sheathing alone.
You should guy it every 10 feet. That being said, there is no substitute for using common sense and making sure that it can't fall down or rip up your roof. You would be amazed at how easy it is to fall off of a roof or end up dead from electrocution, even for a smart experienced person. Get some assistance. How about setting up a 2o foot section of one piece 1.25″ conduit anchored next to the house with a small extension piece (5') on top and you can even possibly use the antenna wires to help guy the top section. You could also put a ringo on top for your FM rig and the neighbors wouldn't think it too ugly. You might also want to use some kind of plastic arm to extend the antenna out from the metal pole a bit(8-10″). Good luck, and one more thing, don't wait until it is blazing hot to go on your roof. All this I have learned the hard way, sorry to say. 73
Thanks for the suggestions guys. I have the DX-EE up and running fine now. I used dacron rope for the guys, as it has amazing durability, and doesn't stretch too much.
I have the DX-CC antenna (similar sort of idea to the DX-EEand use it for church nets Saturday morning. I drive mine with 450 ohm ladder line so that I can use it on other bands or extended band width. It works great. I'm using it on 80m and at 30 feet or so up it is running NIVS propagation. In other words the signal goes up to the ionosphere and some of the signal is mirrored back down over a radius of about 300 miles max. From Victoria BC I can reach Vanderhoof BC, Calgary Alberta, Portland Oregon, and Seattle which is fairly close. If you are an emergency communications specialist for your ward or stake this is the mode you need to be able to operate in. You don't want the signal to leave at a shallow angle and reach someone thousands of miles away when dealing with a local emergency. It's a great way to go. No repeaters required. Mind you space weather and time of day are significant factors as to when you can communicate. The ionosphere is a fickle ally.
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