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post #1 of 12 Old 01-03-2015, 11:54 AM - Thread Starter
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Now you see it, now you don't

I run a decent Antennacraft $99 UHF-VHF antenna and 20 db amp in the attic of my garage (no outdoor location for "personal reasons".) Until a few weeks ago I got quite a number of stations 35 air miles away. Now I get all but two key UHF network affiliates, but I am seeing zero signal on those all of a sudden. My roof unfortunately is slate which can't help, but why do they come in in the summer but not winter? or have they perhaps altered their signal or are winter temps tougher on reception? (Tried grounding the antenna to the ground of an AC outlet nearby but no joy.) Key question is: Would moving up to a 30 db amp help or is this likely to be a waste of time?
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post #2 of 12 Old 01-03-2015, 04:06 PM
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Something in your system is now busted. Just changing to higher gain amp without any diagnosis is an unwise course of action.
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post #3 of 12 Old 01-04-2015, 07:53 AM - Thread Starter
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Quote:
Originally Posted by ProjectSHO89 View Post
Something in your system is now busted. Just changing to higher gain amp without any diagnosis is an unwise course of action.
What do you mean by busted? It is a simple antenna with new 75 ohm RG6 and does pull in quite a few stations. Sorry, but you lost me there, though I fully agree a bigger amp might do nothing.
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post #4 of 12 Old 01-04-2015, 08:18 AM
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A loose wire, a rusted connection, something simple. Try checking your entire signal path before you do anything else.

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Did you really need to quote that entire post in your reply?
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post #5 of 12 Old 01-04-2015, 08:41 AM - Thread Starter
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Originally Posted by LastButNotLeast View Post
A loose wire, a rusted connection, something simple. Try checking your entire signal path before you do anything else.
Good idea and thanks. Setup is only a year old including cabling, but I will look over carefully. How important to ground the coax given location in attic? Same question for antenna.
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post #6 of 12 Old 01-04-2015, 10:05 AM
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What do you mean by busted?
It means something has failed. Connection, balun, cable, preamp, etc.

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How important to ground the coax given location in attic? Same question for antenna.
There is neither a requirement nor a reception benefit to grounding an antenna in the attic.
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post #7 of 12 Old 01-05-2015, 12:36 PM - Thread Starter
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Quote:
Originally Posted by ProjectSHO89 View Post
It means something has failed. Connection, balun, cable, preamp, etc.

There is neither a requirement nor a reception benefit to grounding an antenna in the attic.

That was what my gut told me also. I do not see any connection/corrosion issues so my sense is that these stations were marginal and now in winter, leaves gone from trees, etc. have dropped off. The other possibility is that I have an antenna that is perhaps not the greatest for UHF.
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post #8 of 12 Old 01-05-2015, 12:51 PM
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Weather also affects my antenna signal

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post #9 of 12 Old 01-07-2015, 06:19 AM
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You might be getting interference.
If your TV can get analog stations, see if there are any low-powered analog stations receivable in the area, and see if they are getting clobbered by interference (lines, bursts of static, etc). An AM Radio can also tell you if there are wide-band noise sources, like arcing switches/thermostats, electrical noise from motors (furnace blowers, etc).

Also, run a search on your location, on TVFool, AntennaWeb or Rabbitears.info. See if there are any new stations really close to you, that might be overloading the antenna amplifier.

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post #10 of 12 Old 01-07-2015, 07:51 AM - Thread Starter
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Originally Posted by kenglish View Post
You might be getting interference.
If your TV can get analog stations, see if there are any low-powered analog stations receivable in the area, and see if they are getting clobbered by interference (lines, bursts of static, etc). An AM Radio can also tell you if there are wide-band noise sources, like arcing switches/thermostats, electrical noise from motors (furnace blowers, etc).

Also, run a search on your location, on TVFool, AntennaWeb or Rabbitears.info. See if there are any new stations really close to you, that might be overloading the antenna amplifier.
Much obliged, Ken. Will do all those things when I get a moment. I have not really added anything inside the house (though I did move from a Sony XBR6 to XBR850) from a noise-generating equipment standpoint, but will look into your suggestions.
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post #11 of 12 Old Yesterday, 09:37 AM
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Did you lose those channels about the same time your garage became covered by snow and ice?

Ice and snow on a roof won't completely block VHF and UHF RF from getting to your antenna, but it could be the difference between having a signal barely strong enough for decode (which, unlike analog, results in a perfect DTV picture, with no snow) and having a signal just not quite strong enough for decode (which, unlike analog, results in no picture nor sound, rather than a snowy picture).

One other note - devices that interfere with the AM broadcast band usually won't affect UHF (though are a little more likely to cause problems on high-VHF and often do on low-VHF, the latter no factor in the Detroit area unless you're trying to watch WLMB (virtual 40/RF 5).
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post #12 of 12 Old Yesterday, 10:59 AM - Thread Starter
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Quote:
Originally Posted by itsthemultipath! View Post
Did you lose those channels about the same time your garage became covered by snow and ice?

Ice and snow on a roof won't completely block VHF and UHF RF from getting to your antenna, but it could be the difference between having a signal barely strong enough for decode (which, unlike analog, results in a perfect DTV picture, with no snow) and having a signal just not quite strong enough for decode (which, unlike analog, results in no picture nor sound, rather than a snowy picture).

One other note - devices that interfere with the AM broadcast band usually won't affect UHF (though are a little more likely to cause problems on high-VHF and often do on low-VHF, the latter no factor in the Detroit area unless you're trying to watch WLMB (virtual 40/RF 5).

Did you lose those channels about the same time your garage became covered by snow and ice?

I do not think that was it, as we have not had much at all in that regard, but thanks for weighing in.
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