Altitude is Relative

I have had some trouble getting a signal all the way back to Fort Worth. In fact the repeater I frequent is pretty much exactly 28 miles away. 50 watts into a 6.5 dBi omni antenna *should* look like 136 watts, but that doesn’t account for the hillside between here and there.

Our property is downhill from the street, but today I used a builder’s level to quantify what I believe to be a significant factor in my limited range towards Fort Worth.

For those unfamiliar with a builder’s level, it’s a piece of surveying equipment used most often to ensure structures are level over long distances, particular stuff like driveways or drainage ditches or houses. I first used one when we were building a sand pad for an above ground pool.

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The ground within this circle is 10 inches lower on the left side than the right.

You set up the level on it’s tripod and either leave it where you put it throughout the project or mark precisely where the legs are. Using the bubble level on the device and the adjuster wheels, you set the unit itself level, then using the graduated measuring stick, you look through the little telescope and get the height of the measured point relative to the level plane described by the tool.

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This pic shows the view through the view scope. The ‘6’ is very dim, but in this view, the ground at the measured point is just under 6′ 8″ below the crosshairs in the level.

Well, I did not use the measuring stick because I was looking for much more of a thumbnail measurement (and it’s a pain to do without an assistant), but I set the level up on the street out front and took a sighting off the antenna on the workshop.

The level is 5 feet up from the street. Once set, the level sighted the workshop just a few inches below the roof peak. Go down 5 feet from there and it’s about the bottom of the antenna mast.

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So… the antenna mast is essentially sitting at street level, meaning the base of antenna itself is only about 9 feet above the ground in the direction of the repeater.

Even with a beam, I will probably need to get some more height.

 

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