Are TV antennas additive?

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  • atgcpaul
    Veteran Member
    • Aug 2003
    • 4055
    • Maryland
    • Grizzly 1023SLX

    Are TV antennas additive?

    I've got a decent antenna in my attic that feeds OTA signal to a few TVs in the house. The problem is one station is about 180 degrees in the other direction from all the other stations so I can either get great reception on all but one station, or mostly good reception most of the time. Of course, it's a PBS station with all the WWing shows.

    Anyway, can I flip a cable splitter around so two antennas (one pointed one way and another pointed another) go in and one signal comes out down the cable to the other TVs?

    Maybe get a bigger antenna? I also have a powered signal booster in line after my antenna which helps tremendously.

    Since I'm already working on ladders and such, I may finally bring the antenna to the outside, but I would really like to not have to get on my roof.

    Thanks,
    Paul
  • dandee
    Handtools only
    • May 2006
    • 1
    • Duluth, GA
    • Ryobi bt3100

    #2
    Same Problem

    I don't know the answer but I have exactly the same problem!

    Comment

    • Zip1
      Forum Newbie
      • Dec 2004
      • 19
      • Milwaukee, WI, USA.

      #3
      Yes

      Typically, TV antennas can be combined to produce stronger signals.
      Make sure you are using a decent quality passive (non-amplified) splitter.
      Understand that there is some (minor) loss in the splitter/combiner circuitry.

      Larger TV antennas will retrieve a stronger OTA signal but designs typically do this by making them more directional, so if the transmitters are not in the same direction, a larger antenna may not be the best solution.

      For the best reception, cable companies often purchase antennas specifically built for each channel frequency, direct them individually and then combine them using splitter/combiners.

      Comment

      • LCHIEN
        Internet Fact Checker
        • Dec 2002
        • 20913
        • Katy, TX, USA.
        • BT3000 vintage 1999

        #4
        Yes Zip1 is right.
        you can add the signals using a splitter in reverse. you cannot simply "Tee" them together.
        You will get a loss of 1/2 the signal strength when you do this. THis won't be a problem if you have strong signals. It will be a problem if you have some signals from the same station coming in from each antenna. in the old analog days you would have ghosts because one signal usually had different path lengths from the other and the weak signal would appear as a dim second image set a bit to the right or left.
        I'm not sure offhand what it means with the digital signals. but the problem is called multipath distortion.

        You can avoid the loss and the mutilpath by using an antenna switch but then you will have to remember to switch the antenna each time. Actually you can still have multipath but it will be with two signals reflecting off different objects arriving at the same antenna, not two antennas getting different signals.
        Loring in Katy, TX USA
        If your only tool is a hammer, you tend to treat all problems as if they were nails.
        BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questions

        Comment

        • rfisher7381
          Forum Newbie
          • Dec 2005
          • 59
          • Hudsonville, MI, USA.

          #5
          I just installed an antenna in our attic. It has two elements which can be independently adjusted. Each element has a coax cable which connected to a splitter that came with the antenna. I was then able to aim each element as I needed for best reception.
          Randy

          Comment

          • capncarl
            Veteran Member
            • Jan 2007
            • 3564
            • Leesburg Georgia USA
            • SawStop CTS

            #6
            Add the second antenna in the attic and couple it with the splitters. Best of both world and a heck of a lot less cost than satellite.

            Comment

            • mpc
              Senior Member
              • Feb 2005
              • 979
              • Cypress, CA, USA.
              • BT3000 orig 13amp model

              #7
              Is the problematic station on UHF or upper VHF frequencies? If it's a UHF channel, you don't need the full size TV antenna; most of those bars are reflectors for VHF signal ranges. TV antennas work somewhat like a parabolic microphone: the round reflector part increases the microphone sensitivity and makes it directional. Those varying length bars on the TV antenna are reflectors, each length tuned to a particular frequency range and spaced away from the actual antenna bars (the ones near the center connected to the wire) by a specific fraction of that frequency's wavelength (the "focus" of the reflector bars) The old TV signals were spaced across three separate bands: VHF low (old channels 2 through 6), VHF high (channels 7 through 13), and UHF (14 and up) so the antennas needed several sets of bars each tuned to some piece of those bands. VHF low is no longer used by digital TV... so the longer bars aren't needed. So new TV antennas can be a lot smaller than what folks are used to.

              UHF is much higher frequencies than VHF high and works with those older round loop or "bow tie" shaped antennas - they were tuned to the center of the UHF range. If you have one of those antennas laying around, try that in the attic summed with your existing antenna - that may be all you need. Those loops and bow-ties are somewhat directional too though they "see" in two directions 180 degrees opposite each other. The bow-ties are easy to make too - from old coat hangers or other wire. Lots of DIY instructions on the web with info on how to size them and how to make a reflector (looks like a rack from the oven) to make them "see" in only one direction.

              www.antennaweb.org or tvfool.com will show you what frequencies and what bands your local broadcast stations use... and where the transmitter antennas are relative to your house for antenna aiming. See if your WWing PBS station is UHF or VHF to see if my idea for a smaller/cheaper antenna is sufficient. Find out the "real" channel number to see what band it is in, not the channel you type into the TV remote. Those are "virtual channels" and often have nothing to do with the actual frequency. This "virtual to real" mapping is something new with digital TV.

              mpc
              Last edited by mpc; 10-11-2014, 02:36 AM.

              Comment

              • RAV2
                Established Member
                • Aug 2007
                • 233
                • Massachusetts
                • 21829

                #8
                Slight correcting on the comment by MPC, very few - if any - channels today are on VHF. The digital switch moved all channels to UHF.

                Most "digital ready" antennas are just 1/2 of what we used to get in our larger antennas - UHF.

                To combine antennas, spend a couple of bucks more and buy a proper antenna combiner from a quality antenna supplier.

                In my situation, I have about 6 'homeruns' coming from my antenna thru the use of a 'Zero Loss Splitter' that provides a slight compensation for the loss related to splitting the signal that much. Generally just boost them all to have the expected signal level.

                I get about 28 HD channels for free at home. Been OTA for the past 23 years and using FIOS fiber optic internet for the rest of our media.

                Comment

                • woodturner
                  Veteran Member
                  • Jun 2008
                  • 2047
                  • Western Pennsylvania
                  • General, Sears 21829, BT3100

                  #9
                  Originally posted by RAV2
                  Slight correcting on the comment by MPC, very few - if any - channels today are on VHF. The digital switch moved all channels to UHF.
                  That might be the case in your area (though unlikely), but is not generally the case. Many HDTV channels ARE VHF. For example, if we look at tvfool for Boston, MA we find that eight of the HDTV stations are in the VHF band.

                  With the changeover to HDTV, the existing channel frequencies were reused but assigned virtual channel numbers. For example, HDTV channel 8.1 uses the "real" channel 8 frequency, and channel 5.1 uses channel 5, both of which are VHF frequencies. Channel 2.1, on the other hand, maps to channel 25, a UHF frequency.

                  Analog stations for the most part have stayed in the VHF band, with some exceptions. The authorized analog stations are mostly college and special interest stations.

                  If you want to find the allocation in your area, try www.tvfool.com.

                  One primary benefit of digital transmission (e.g. HDTV) is that a weak signal can be accurately decoded. As a result, we don't get the ghosting common to analog TV. In addition, a less than optimal antenna can often pick up enough signal to decode. So a UHF antenna may be enough, since it will pick up the VHF signals also, just not as well.

                  Bottom line, you should have both VHF and UHF antennas to receive all the HDTV stations in most if not all areas.
                  Last edited by woodturner; 10-11-2014, 10:19 AM.
                  --------------------------------------------------
                  Electrical Engineer by day, Woodworker by night

                  Comment

                  • atgcpaul
                    Veteran Member
                    • Aug 2003
                    • 4055
                    • Maryland
                    • Grizzly 1023SLX

                    #10
                    I made one of these today. So far I've only tried it on my HTPC and not in the attic for the whole house. Seems to work OK. Will let you know later. I already had the balun. I just had to buy some stiff wire.

                    Comment

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