alg2468
04-23-09, 04:32 PM
I removed the black screen from the antenna and the antenna appears to have somewhat improved reception as it is not as directional, and I have no multipath issues after this modification. Anyone else tried this and what were the results?
gjvrieze
04-23-09, 04:51 PM
I removed the black screen from the antenna and the antenna appears to have somewhat improved reception as it is not as directional, and I have no multipath issues after this modification. Anyone else tried this and what were the results?
I have been wondering about this for multi-markets in good signal areas...
Can you post your TVfool results, so that I can compare?
I removed the black screen from the antenna and the antenna appears to have somewhat improved reception as it is not as directional, and I have no multipath issues after this modification. Anyone else tried this and what were the results?
You pretty much nailed it. It becomes a bi-directional antenna with out the screen.
If you bought a new one, you should read this write up.
http://www.hdtvprimer.com/ANTENNAS/TemporaryPage.html
Might want to save the page because sooner or later he will move or modify it.
It is slightly possible the matching network is less effected without the screen there. But the main disadvatage to removing the screen is if you do have multipath.
We have an area of Gainesville FL DMA where the recommended UHF antenna now is an Eagle Aspen (clone of the DB2 at half the price) with the screen removed. This is because in SW Gainesville FL there are two stations about 160 to 170 degrees apart that are the 2 hardest UHFs to receive. Taking off the screen was found to solve the problem in that part of town.
So you must have the same situation, and with no mulitpath, leave well enough alone and leave the screen off.
If you are not familiar with what you did, think looking down from space right over your antenna. The picture a figure 8 with the whiskers pointed - , such it now has not only a lobe away from the side with the whiskers but also now back toward where the screen existed.
It does lower the gain in the direction that used to be the front, but if you have enough signal that doesn't matter.
I am not sure what a single whisker has for gain. Probably about 1.5 dbd? So I would say with out the screen there you probably have only 7 to 9 dbd of gain, but now in 2 directions.
If it works leave it!
A friend in another area uses an Eagle Aspen 2bay (identical, but cheaper clone of the DB2) with the screen removed. He has UHF stations about 150° off axis, and gets good results.
I have a ChannelMaster CM4228 (the old style made in the US). I removed the screen on it and get stations from two markets almost 180° off-axis. Both markets have VHF & UHF DTV stations. Towers range from ~45mi to 70+ miles away. Also using a CM 7777 V/U preamp.
http://i34.tinypic.com/300h8bd.jpg
Removing the screen may lower gain and increase multipath a bit. But many newer tuners aren't affected by multipath.