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Old 06-13-2013, 02:36 PM   #22  
Pete Higgins
Pete
 
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Join Date: Aug 2012
Location: California, 58 miles @112 degrees from Mt. Wilson
Posts: 265
Default Hdb8x

wizwor,

Quote:
wizwor,
When I installed my antenna in the attic, I noticed that moving it a foot this way or that had a big impact on reception. Is this an attic thing?
It is probably an attic thing, but doesn’t necessarily have to be. For example, when I had the HDB8X in my dining room I actually got one of the San Diego stations much stronger (due to reflection) pointing the antenna at the mountain due west of me (~260 deg.) than when it was pointed in the direction the signal comes from (~168 deg.). Pointed west, I couldn’t get the other two San Diego stations at all. In your attic, your antenna is in a lot closer proximity to things that will disrupt its radiation pattern not to mention all the attractive reflective surfaces. Attics can act like an RF pin-ball machine. Also, things like vents or decorative siding can channel signal more strongly to some areas than others. While terrain and propagation anomalies can similarly affect reception, it’s usually much less pronounced for an antenna in the clear. Plus you don’t have the signal loss associated with penetrating siding & roofing material.


Quote:
wizwor,
If not, how did you choose the location for your tower?
See photos.





I already had a large aluminum tower mounted to my patio roof in front of my chimney and the push-up mast at the south end of the house. I picked the only place I had left where the antennas could be rotated and not hit each other. I did try the CM-4228 attached to the front leg of the aluminum tower and couldn’t notice any difference as I moved it up from 4’ (13’ AGL) to about 12’ (21’ AGL). Keep in mind, I can only measure SNR and as was pointed out to me in another forum, no or small changes in SNR can mask relatively larger changes in signal strength. From my days helping install TV antennas 50 years ago, location was dictated by where a push-up mast could be reasonably mounted & guyed and where the coax (back then twin-lead) could be run into the house.
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