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Old 13-Jul-2012, 1:32 AM   #11
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Join Date: Jul 2012
Posts: 9
Originally Posted by GroundUrMast View Post
Rather than chasing after the KIRO translator on Vashon Island, K47LG, work on the signals from Queen Anne and Capital Hill.

You mention trying to see over trees and houses. Those tend to be significant obstacles for some. Are you aiming directly into a house or trees?

Electron's suggestion re. adding a VHF dipole kit is on the right track in that it should add CH-11 and CH-9, but I'd like to know how much tree and building obstruction you're dealing with. Getting over or around big obstructions may be challenging but it very often is more effective than just increasing the antenna size.

An example of edge diffraction can be seen during sunrise and sunset. With the sun below the horizon, some light is bent, some scattered by the atmosphere. You don't have a direct view of the light source, yet some of it's light makes it to your location. Radio waves behave in a similar fashion. Click on the call sign of a station listed on your TV Fool report and you'll see a graphical depiction of the transmitter on the left, terrain in the middle and your receiving location at the far right side of the graphic. KOMO-TV 38 (from your TV Fool report) for example shows the transmitter on top of Queen Anne Hill, terrain sloping down toward Eliot Bay, then half way across the graphic, the terrain of West Seattle sloping back up to a major hill top followed by a second hill top close to your location.

The bottom line is, you often need a more directional antenna to reliably receive a TV signal when you're dealing with edge-path reception. The idea is, you want to receive only one copy of the signal, not several that come from slightly different directions due the scatter effect. Also, edge-path signal strength tends to fluctuate more than direct line of sight. Again, an antenna with higher gain and directivity is useful in this situation. You start by aiming the antenna toward the station of interest, but fine tune the aim for best overall reception.

FWIW, the KUNS transmitter is still on Tiger Mountain. There's a construction permit to move it to Queen Anne but that's not yet done.

I am aiming the antenna with a slight inclination so (I hope) the antenna is seeing just over the house and trees. I actually have a photo that I will try to attach later if I am so allowed, and I can figure out how to do so. Actually, I have tried several inclinations, and I am certain that some of them cleared the obstructions.
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