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Discussion Starter · #1 ·
I’m having a problem with dropouts on my OTA digital channels. I am getting signal strength in the 90 – 100 range. However, I am getting dropouts randomly on all of my digital channels. Sometimes these dropouts do not appear for hours, and sometimes they are every 30 seconds. I am using a CM 3010 “Stealthtenna†in my attic (about 15-18 feet from the ground). The CM 3010 in connected to a CM 3042 amp, which then runs about 100 feet to my Mitsu SR-HD5. The dropouts seem to occur at random times, and on random channels. The signal strength drops from 100 to 0, then back up again. I have the CM 3010 pointed west, so the booms face southwest and northwest, the directions of the digital towers. This direction seems to give me the best signal strength, but I still get the dropouts. To resolve this problem I am considering getting the CM 7777 pre-amp. Will this help my situation? I need to keep the antenna in the attic, so I can not go much bigger. However, I may be able to fit the CM 3016. Would this help?

Any ideas would be greatly appreciated!

Thanks.
 

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A preamp isn't going to help with signal levels in that range and actually may make things worse.


There are several things that may be causing the dropouts. The two most likely ones are:


1. You are actually receiving multipaths (ghosting on analog) when they get bad enough they will cause dropouts, using an amp will make it worse, a ghost killer will make it better.


2. The problem is on the station side and isn't something you can control. The station isn't sending enough foward error correction bits.


Since most stations have just started transmitting it is not uncommon for the stations to have problems like you are describing.
 

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That stealth antenna is multi-direction, so is prone to multipath which can cause dropouts. You should try a more directional antenna.
 

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Discussion Starter · #4 ·
Ok, so it seems that my problem is with multipath. The problem with getting a more directional antenna is the stations are both UHF & VHF and in opposite directions (southwest & northwest). This is why I chose the CM 3010, because it basically "points" in two directions. Any other antenna options that would give me UHF/VHF from opposite directions with less of a multipath problem? Any other ways of solving the multipath problem?


Also, what exactly is a "Ghost killer", and where can I get one?


Your help is appreciated.

Thanks again guys
 

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I believe Channel Master has ghost killers. Basically they are devices you put on your feed line from the antenna that blocks the reflected signals. I don't have a website for you, perhaps someone else does.
 

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Quote:
Originally posted by bryan27
I believe Channel Master has ghost killers. Basically they are devices you put on your feed line from the antenna that blocks the reflected signals. I don't have a website for you, perhaps someone else does.
I agree that the problem is multipath, but this is too rich! Channel Master used to make an antenna called a "ghost killer" that was essentially an antenna that came in parts - a VHF reflector boom for the back and more directors for UHF on the front, but it was little more than an antenna designed to fit in attics.


If there was such a device, every HD STB manufacturer would be including the technology in their boxes.


The original poster's best bet may be to go with two small VHF/UHF combos and a remote-switching A/B box to select the right antenna. But please, people, before you start posting about magic products that do incredible things, at least find a link to the actual product that verifies some of your claims.
 

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Do not go with Channel Master 3016. A lot of people have problem with getting UHF signal from the attic. I had better luck with R.S VU-90XR and if it does not work for you, you always can return it.
 

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Discussion Starter · #8 ·
So do not go with the 3016. As far as using dual antennas, as I already have the CM 3010 which receives both UHF/VHF equally, what type of second antenna should I get? UHF, and use the 3010 for VHF, or vice-versa? Also, this "Ghost Killer" I have searched, but can not find any info on it. Does it exist?

Thanks!
 

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Quote:
Originally posted by sregener
If there was such a device, every HD STB manufacturer would be including the technology in their boxes.
Actually there was/is such a device. I remember seeing it shown at a NAB (National Association of Broadcasters) display about ten years ago. It effectively eliminated ghosts from analog TV signals. The NAB device was a great improvement on the earlier "delay box" which would sum a delayed signal with a ghosted signal to try and cancel out the echo's.


Such boxes would probably help HDTV multipath signals, but are not included by STB vendors just as they weren't included with analog TV's.


Adaptive equalizers are built-in to the STB's and they are designed to combat HDTV multipath. This technology will improve in the next generations of STB's to appear on the market.
 
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