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  1. Member
    Join Date: Mar 2003
    Location: Canada
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    I recently got a HDTV tuner for my PC. I have an antenna whose cable goes into my basement, is split from there up into my bedroom. In the basement connected directly to the antenna I get 95% signal strength, after the first splitter I get 80%-85%. After going up into my room reception is at 65%-75% after splitting the cable in my room into my TV and PC I'm at 55% signal strength, which is unwatchable. I'll be using the amp for both digital and analog reception.

    I'm looking into putting a powered UHF/VHF amplifier in the basement but there are so many choices I don't know what to get. I'm looking to get one off ebay if possible.

    Should I get one with a single output at the highest gain (36db) possible?

    What's better a single output model with 24db gain on the single output with a separate splitter, or a dual output model with 12db gain on each output with no splitter?

    Is it important to have an ajustable gain on the amplifier?

    What are the chances an amp will worsen reception?

    Does brand really matter when it comes to amps?

    Is this good enough for what I need to do? http://www.summitsource.com/philips-magnavox-m61111-24-db-tv-aerial-antenna-dual-outpu...11-p-4642.html

    Does anyone have any good resources explaining Antenna gain and amplifiers?

    Thanks for the replies.
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  2. Member edDV's Avatar
    Join Date: Mar 2004
    Location: Northern California, USA
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    Winegard and ChannelMaster seem to be the most mentioned quality amps.

    http://www.winegard.com/offair/sigamplifiers.htm
    http://www.copperbox.com/lite/antenna.php
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  3. Member
    Join Date: Feb 2004
    Location: Australia
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    You have a messed up setup happening ... never place these device's after rf splitter's .

    You have tv feedback signal interference issue .

    Antenna > hdtv tuner > cable + rf splitter's to tv's ... the only correct method to receive quality on all unit's .
    The rf's stop feedback signal from each tv from appearing on other set's (channel ghosting interference)

    As for amplifier's :

    Antenna > amplifier > hdtv tuner > cable + rf splitter's ... the only method .

    Ps : I have had many of these amplifier's , and 90% are a waste of money ... better investing in a better antenna and cable's .
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  4. Member edDV's Avatar
    Join Date: Mar 2004
    Location: Northern California, USA
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    I've read, but can't find the link, that these amps work best for deep fringe reception with a tightly focused antenna. Closer in you risk overamplication of multipath reflections. And as said above, they go up on the mast close to the antenna.
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  5. Member
    Join Date: Mar 2003
    Location: Canada
    Search Comp PM
    Originally Posted by Bjs
    You have a messed up setup happening ... never place these device's after rf splitter's .

    You have tv feedback signal interference issue .

    Antenna > hdtv tuner > cable + rf splitter's to tv's ... the only correct method to receive quality on all unit's .
    The rf's stop feedback signal from each tv from appearing on other set's (channel ghosting interference)

    As for amplifier's :

    Antenna > amplifier > hdtv tuner > cable + rf splitter's ... the only method .

    Ps : I have had many of these amplifier's , and 90% are a waste of money ... better investing in a better antenna and cable's .
    I haven't bought an amp yet so I can't see how I have a messed up setup.

    Current setup:
    Antenna>basement splitter(TV+cable)>cable to bedroom>splitter(TV+HDTV PC)
    It's impossible for me to put the HDTV tuner right at the antenna because my computer is in my bedroom. The signal has to be split once in the basement then again in my room after a lengthly run of cable. I'm not looking into a pre-amplifier which goes on the antenna, I'm looking for one which goes in my basement after a lengthly cable run from the antenna into the basement. Like I said I tested having my HDTV tuner in the basement connected directly to the antenna and get 95% signal strength, so the problem is with the multiple splitters and the long cable run into my bedroom.


    edDV

    I'm looking into a normal amplifier, not a pre-amplifier which goes on the mast, since my reception seems good enough after the first cable run from the antenna to the basement. I need help deciding what amp to get.

    http://www.copperbox.com/lite/popinfo.php?lc_code=CM-3042&PHPSESSID=8b0a7d2fa665e4eea7c491bfb2471866

    For example, this is a channel master 13db single output amp. I've seen some amps from other companies with up to 36db gain on a single output. Is higher necessarily better? Is getting an amp with adjustable gain a good idea?


    Thanks for the help.
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  6. Mod Neophyte Super Moderator redwudz's Avatar
    Join Date: Sep 2002
    Location: AZ, USA
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    A amplifier with adjustable gain may be a good idea, if you get a good quality one. You would want the amplifier before the splitters. The reason a mast mounted preamp is better for most installations is to boost the signal above the long cable run signal loss. It's similar with the amplifier before the splitters. That way you are not amplifying any unnecessary noise.

    An even better setup than the amplifier by itself would be a distribution amplifier at the antenna cable in. Then you could eliminate the lossy splitters and probably some crosstalk and noise within the cables. But if you don't want to run separate cables, try just the amplifier.

    How much amplification? Too much can cause more problems, because you are also amplifying noise and interference. 36dB gain is unlikely, I would examine their specs and read the fine print. You would want to find out what frequencies that stated gain is on. A good brand of amplifier should include a graph of it's performance vs frequency response. It won't do you any good if it's not for the frequencies you want to receive. 13 - 20dB is more common.

    If you amplify a good signal too much, you can overdrive your video tuners and that can degrade the video. I'm assuming you are using good quality cables, connectors and splitters throughout the system? They can potentially cause the most interference and signal loss.

    If all the TV stations you want to receive are in the UHF band, such as most HDTV, you don't really want to amplify lower frequency signals. If so, you might look for a amplifier that is only for the higher frequencies and blocks the lower ones. Or possibly a filter may be added to block them. Probably not a big deal, just something else to consider.

    Also make sure the antenna lead in is well grounded on the shield side. This is important both for lightning protection and noise elimination. The grounding block and stake would be on the outside of the building, with the antenna coax feeding through it. A surge protector on your amplifier is a good idea also.

    I've dealt with a few long distance TV station antenna setups. We put together a antenna tuned for a specific TV station a few years ago. The station was VHF and about 300 miles away. The signal got there by atmospheric changes along the coastline. No direct signal was possible. It would drift in and out, depending on the weather. An amplifier didn't help much as it amplified too much noise. An interesting experiment, but not really practical for good reception.

    Hope this gives you some ideas. If you are wanting to find out more about antennas and feed systems, you might go to your library and look for books by the ARRL (American Radio Relay League) Some of these books for 'hams' have quite a bit of info on antennas, amplifier designs and setups that can be applied to TV reception.
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