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OTA Advice Needed

Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by Johnny Kranthos, Jul 27, 2007.

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  1. Johnny Kranthos

    Johnny Kranthos Cool Member

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    Jul 5, 2007
    Hey Guys, enjoying the 2 HR-20's so far (had them only a couple days now) And was figuring on just getting the locals thru the dish. Last night I was getting some strange audio issues on NBC only and wondered if I had recorded the show OTA would they have been there? I have my old HR10-250 still hooked up to this Sony SXRD for now during this transitiion period and it has the OTA from the roof still hooked to it. What would you do if you wanted to send that signal to 2 other machines for a total of 3 DVR's on the same antenna? Or would you get something else all together to hook to these 2 HR-20's? Thanks for any help!

    Johnny
     
  2. Canis Lupus

    Canis Lupus You make it, We break it

    4,722
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    Oct 16, 2006
    Hi Johnny,
    The only problem with splitting off your antenna input to multiple boxes is a degradation in the signal strength being distributed. If you do a search, you should find a number of discussions on, and solutions to, splitting out that signal from your antenna. In a nutshell, you can do it but need a distribution amplifier of some sort to keep those signals strong to the 2 or more boxes.
     
  3. houskamp

    houskamp Active Member

    8,636
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    Sep 14, 2006
    If you have enough signal level just a simple splitter will do...
     
  4. Canis Lupus

    Canis Lupus You make it, We break it

    4,722
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    Oct 16, 2006
    Yes - sorry - i meant to say MAY degrade. oops.
     
  5. hasan

    hasan Well-Known Member

    5,957
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    Sep 22, 2006
    Ogden, IA
    I have 4 splits to my antenna. If you do it right, it's not a problem.

    As for doing it right, search for my posts on OTA and the HR20 where I go into great detail about how to do it "right". There are many ways to do it wrong and get very poor results. If you can't find the info I have posted (many times), come back in this thread with the following information and I'll go through it with you:

    1. How far and what direction (all the same or different) are the desired stations?

    2. Are they all UHF or are some VHF?

    3. What kind of antenna are you using now? How high is it (outdoors or indoors)?

    4. How long is your feedline to the antenna? I assume it's RG-6, if not what is it?

    Be wary of "distribution amplifiers". They tend to have a lot of gain and very poor noise figures (which is THE CRITICAL FACTOR). There are better alternatives.
     
  6. Johnny Kranthos

    Johnny Kranthos Cool Member

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    Jul 5, 2007
    Thanks Alot hasan! Great Info and a tremendous help!

    1) I'm in las vegas and the Local Antenna's are on a mountain that aren't to far from me. I would say within 10 miles. They are South from me.

    2)There are a couple that are VHF.

    3)Currently I'm using a Outdoor antenna that is on my roof. I have a single story ranch style home. I would say that its maybe 15 feet off the ground.

    4) My feedline is RG6 and I would guess that it's at most 35 feet away from the HR10-250 which it is currently attached to.

    Thanks again for the help!
     
  7. hasan

    hasan Well-Known Member

    5,957
    54
    Sep 22, 2006
    Ogden, IA
    OK, let's start simple (and not invest in anything that might not be useful if we have to increase our efforts).

    With the stations all in one direction and that close, you should have plenty of signal to work with, given an outside antenna and a feedline that is not excessively long. The only issue you need to potentially worry about is multi-path distortion (that the HR20 is particularly susceptible to) Multi-path is the result of reflections from large objects like buildings, water towers, etc.). I assume the antenna is in good shape, no bent elements, rusted connections, poor feedline connections, etc.

    Your outside antenna sounds like it is a combo vhf/uhf, that is good. It has a series of very short elements and a few much longer elements. How many long elements does it have, how many short elements, and what is it's overall length from end to end? (This isn't critical at this point, I'm just trying to get a good feel for what you have...if you know the Manufacturer and Model Number, I can look it up, but just a description is fine).

    With the likelyhood of this much signal, all you have to do is passively split the signal.

    You need to get a decent 3 way splitter. Go to solidsignal.com (google it), and look at what they offer. If you have questions, get back to me and I'll suggest what to get. You could run down to your local radio shack or other store and get whatever cheap piece of junk they may have laying around if you're in a hurry, but you have no idea what you might be getting...may work, may not. I buy good ones myself, and then I don't have to worry about them.

    The real problem is where your various TV's may be located. You need to connect the 3 way splitter directly to the TV antenna lead in, and then run your splits to the various TV's. Where are they and how far from the splitter are they located? If you have to run another 40 or 50' to another TV, in addition to let's say 40' from the TV antenna itself, you now have a run of 90' and that's a lot of loss.

    Here is what I would try:

    1. Get the good quality 3 way splitter.
    2. Run the splits to each TV/DVR
    3. See what you get.

    TV Antenna > 40' of RG-6 > 3 way splitter >
    > TV/DVR 1
    > TV/DVR 2
    > TV/DVR 3

    DON'T LEAVE ANY UNUSED OUTPUTS....if one is not going to be used or empty, put a 75 ohm termination on it. These are available at Radio Shack (or if you go to solidsignal with another order, you can order them there, dirt cheap)

    If what you get doesn't work, don't worry, you haven't wasted any effort or money.

    Next:

    Buy a Channel Master 7777 mast mounted preamp (we are going to use it as a distribution amp, not out at the antenna, as you shouldn't need it there) You can get it from SolidSignal.com. DON'T BUY A GARDEN VARIETY DISTRIBUTION AMP!

    Here is what things will look like with the preamp:

    TV Antenna > 40' RG-6 > Preamp > 3 way splitter >

    > the rest is the same as above.

    What you are doing here is using a low noise, moderate gain preamp to make up for splitter losses. All losses AFTER the preamp become essentially non-existent. Your "sensitivity" is SET or DETERMINED by the location (and noise figure) of the first RF amplifier (in this case the preamp) after the antenna. The best location for the antenna mounted preamp is at the antenna itself (except when you already have a tremendous signal, in which case you don't want it out there). In your situation, you aren't going for maximum signal, you are simply making up for splitter losses.

    If you do this, you can run practically as many splits as you like. I have a total of 7 splits using this technique, and every TV/DVR has a perfect signal.

    If you need the preamp as a distribution amp, you should also get a variable attenuator, so the preamp doesn't overload any of the TV/DVR front ends. Too much signal will kill the performance of any TV tuner. The proper place for the variable attenuator is AFTER the preamp (at its output) and BEFORE the splitter.

    This all may sound complicated, but it really isn't.

    Start simple, just the passive splitter.
    Add the preamp if needed. (power for the preamp is sent up the coax)
    Add the attenuator if needed (although if I was ordering a preamp I'd get the attentuator at the same time)

    Don't be tempted to go to an indoor antenna with built in preamp. You already have a good outdoor antenna (virtually ANY antenna outdoors will outperform the very best indoor antenna by a large margin).

    Come back with questions and let us know how you make out.
     
  8. Johnny Kranthos

    Johnny Kranthos Cool Member

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    Jul 5, 2007
    hasan! thank you so much for the help!

    I'm not sure on the make or model of my antenna. But I looked through the solid signal site and it looks very similar to the Channel Master 4220

    http://www.solidsignal.com/prod_display.asp?PROD=CM4220

    The grill on mine is a little differant. It has 6 horizantal elements on the top and bottom with a few inches with no horizontal elements in the center (just the vertical ones which are consistent throughout) And it has 2 bow ties in front of the grill.

    It was installed by D* about 17 months ago when i got my HR10-250. It looks to be still in good shape. Over the first year I would occasionally get some video and audio dropouts. Not very often but just enough to be annoying and I always wondered if DTV gave me a cheap antenna although my signal reading on the dvr is strong.

    I, like you, prefer quality gear and will definately pick up these items you suggest from solidsignal and not go the cheap route. Currently I have all 3 dvr's at one location. But in the near future I will be taking one to another room. I have my switcher in a walk in closet and I'm thinking that will be a good spot to put the splitter, preamp and attenuator. The distance from that location to all the dvr's at the moment will be less than 10 feet.

    Do you think the antenna I currently have can do the job or should I consider an alternative?

    Thanks again for your time and help, it is greatly appreciated!
     
  9. hasan

    hasan Well-Known Member

    5,957
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    Sep 22, 2006
    Ogden, IA
    That antenna is UHF only. Am I getting foggy in my old age? I thought you said you needed both UHF and VHF. If you are UHF only, then this antenna should be fine. If you need both, you are so close, that you "might" get away with it, but it is not a good antenna for VHF. At this point, I'd try it, just for giggles...it costs you nothing.

    I don't see any reason you would need a preamp at this point.

    Let us know how you make out....if your VHF stations don't come in, we need a plan B...and I have one ready for ya!:)
     
  10. NR4P

    NR4P Dad

    6,382
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    Jan 15, 2007
    Sunny Florida
    Hasan, You may want to get that plan ready, I went to antennaweb.org and noted that all four networks are VHF digital. And of course, not all the antennas are in the same place.

    Johnny, check out the site and plug in your home address and you will find out exactly where the antennas are and what the actual physical digital channel is (i.e. not the virtual) in the very last column of the chart.

    Good Luck!
     
  11. Johnny Kranthos

    Johnny Kranthos Cool Member

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    Jul 5, 2007
    * yellow - vhf KLAS-DT 8.1 CBS LAS VEGAS NV 155° 8.4 7
    * yellow - uhf KINC-DT 15.1 UNI LAS VEGAS NV 155° 8.3 16
    * yellow - vhf KTNV-DT 13.1 ABC LAS VEGAS NV 155° 8.4 12
    * yellow - uhf KVCW-DT 33.1 CW LAS VEGAS NV 124° 5.3 29
    * yellow - uhf KBLR-DT 40.1 TEL PARADISE NV 122° 5.3 40
    * yellow - vhf KLVX-DT 10.1 PBS LAS VEGAS NV 124° 5.3 11
    * yellow - vhf KVBC-DT 3.1 NBC LAS VEGAS NV 123° 5.3 2
    * yellow - uhf KVMY-DT 21.1 MNT LAS VEGAS NV 124° 5.3 22
    * violet - vhf KVVU-DT 5.1 FOX Henderson / Las Vegas NV 124° 5.8 9

    Hmm, this is a list of my local digital stations according to antennaweb.org (thanks NR4P)

    I see that there are several vhf's listed. But i do get those currently thru my current UHF antenna. Does this mean that I could get them even better with an antenna that also has VHF?

    Thanks for the help guys!
     
  12. hasan

    hasan Well-Known Member

    5,957
    54
    Sep 22, 2006
    Ogden, IA
    Oh yeah, that's what it means alright. Right now you are getting them out of "blind stupid luck" (not directed at you, but at the miracle of propagation). The chances of something like you are using working well for both VHF and UHF is certainly no better than 50/50. But, hey, if it works it works! So, try it first and see what happens. If no go, we'll be talking about an outside combo vhf/uhf antenna to replace the uhf only one that's out there now.

    The gain and pattern of a UHF only antenna on VHF is going to be a "mess". It will have very poor gain, and who knows what kind of directivity. Since you are so close, gain doesn't matter. If, however, your area is subject to multi-path (you get a lot of ghosting on vhf analog channels, for example), then that antenna is very poor for the HR20 as it doesn't do well with multi-path.

    So, look at your analog VHF channels with your existing antenna. If they don't show any ghosting, you could well get away with not changing your antenna at all. Better to be lucky than good sometimes.:)

    Keep us informed and good luck.
     
  13. Johnny Kranthos

    Johnny Kranthos Cool Member

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    Jul 5, 2007
  14. hasan

    hasan Well-Known Member

    5,957
    54
    Sep 22, 2006
    Ogden, IA
  15. Johnny Kranthos

    Johnny Kranthos Cool Member

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    Jul 5, 2007
    I'm putting my order together for solidsignal and I'm wondering if i need better connectors for my rg6 cables. I'm going to need 3 8 foot long cables to go from the splitter to the dvr's. I have some gold connectors that I got from home depot several months back, will those work or should i get some of these pro installer quality connectors? Also, solidsignal has packs of 10 or more for the 75 ohm terminator. I did see one $1.99 winegard but they want $16.95 for shipping..ouch. Is there a big differance between 75 ohm terminators?
     
  16. hasan

    hasan Well-Known Member

    5,957
    54
    Sep 22, 2006
    Ogden, IA
    I'm going to give you the "fanatic" answer. If you do a lot of connectors, you should get the high quality compression type fittings and the compression tool (you have to have the tool to do them). I got one from solidsignal and I have never looked back. I redid EVERY F connector cable in the HOUSE!!!

    It is so easy and the quality of the connections is outstanding!

    Inside connections (again if you aren't fascinated by the compression fitting style), you can use anything and it won't make a differences as long as you do a good job of installing the connectors What's nice about the compression fittings with tool for installation is that it is nearly impossible to do them less than perfectly. I bought a bag of 50 connectors and a tool when I made my order from solidsignal.

    Now...that is nuts for typical inside connections. For outside....I'm not sure I would ever go back to a standard connector, unless I did an "over the top" waterproofing job outside. I would never use a standard connector outside without the following:

    1. A thin layer of Scotch 33 or 88 over the connection.
    2. A layer of "coax seal" on top of the tape.
    3. Another thin layer of Scotch 33 or 88 over the coax seal.

    On terminators...no...it's nearly impossible to do them wrong.

    Also, get the bag of ten if they aren't absurd in price...you can always find a use for them like terminating an unused splitter port....or tracing down the end of a 75 ohm cable by putting the terminator on the far end ...oh...while you are making your order: get a couple double female F connectors and at least 3 or 4 double male F connectors....you WILL need them...and you may find you can eliminate one of your cables by using the double male F connector.
     
  17. mopzo

    mopzo Legend

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    Jun 15, 2007
    I use the little antenna that came with the HR20. The same antenna that is used when you want RF for remote control versus IR.

    On all OTA channels (some VHF and UHF) my signal strength is 90 - 95 % My distances are slightly less than yours (4.6 - 5.1 miles from the antennas) all within a 10 degree arc. It works great for me and looks a alot better than having rabbit ears on the box.
     
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