# Multipath issues resolved! Read this for proper jointenna use.



## wozman57 (Nov 21, 2005)

I was one of those that thought the OTA tuner in my HD Tivo was broke ... because with my $60 Radio Shack antenna in the attic hooked up to the tuner in my Sony 50' A10 HDTV, all the HD stations came in fine ... but when hooked up to my HD Tivo, the signal quality for most frequencies would bounce from 10 to 80 from 10 to 80. Thanks to this message board, the problem was diagnosed as multipath ... and pointed me to a better antenna configuration. I called up channel master technical support, resulting in the solution attached. This should be a reference for the proper use of a pair on jointennas for a multi antenna configuration. If you are having multipath issues, and only care to receive the main 4 local networks, then I suggest you try my solution. The signal quality for all four networks show up at a constant ~92% for both tuners. All three of my channel master 4221's are mounted in my attic ... I am roughly 24 miles from all the networks I care about (where the 4221 has a range of 45 miles). Each of the three 4221's were only $20 each, where both jointenna's were $30 each. With shipping this solution cost $150 ... well worth the cost of being able to tivo my HD locals. I purchased them from www.warrenelectronics.com ... the jointenna's are special order, which takes 2 1/2 weeks to get to your door (you have to specify the frequency that you want each jointenna to be "tuned to"). For reference, a jointenna works in two ways. The specific frequency input filters all frequencies except for the one it is tuned to. The "all channels" input allows all channels to pass except for the specific frequency. Just as long as the difference between your desired filtered channels is 4-5, you could daisy chain quite a few of these together, each dedicated to a specific frequency. I'm using one antenna to get both NBC and CBS becuse they are located in the same direction and the frequencies are so close together.

The first attachement/picture shows the location of my desired networks at zipcode 28117 from www.antennaweb.org. The second attachment/picture shows my jointenna/antenna configuration.

I hope this helps those that were in the same frustrated situation as I.


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## chris_h (Dec 17, 2003)

Wow, that is dedication! Congrats on getting your OTA working. I now realize how lucky I am that all my OTA comes from the same set of towers.

Just curious, did you check to make sure these four stations are keeping their same frequencies post-transition, or will you be needing to get new jointennas then?


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## vertigo235 (Oct 27, 2000)

I may need to do something like this for one of my channels, which is really close and really powerful, unlike the rest of my channels!


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## vertigo235 (Oct 27, 2000)

I don't see the jointenna on their website? do I need to call them about it?


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## vertigo235 (Oct 27, 2000)

Here is the link to the Joiners

http://www.warrenelectronics.com/Antennas/joiners.htm

Thank you very much for posting this!


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## vertigo235 (Oct 27, 2000)

Hey wozman are you in Charlotte? I'm noticing that you're having the same frequencies that I am for the same stations!


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## vertigo235 (Oct 27, 2000)

AH HA! I've found you, you're in Moorseville!

Good to know you've found a solution to my problem for me  and tested it effectively


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## wozman57 (Nov 21, 2005)

chris_h said:


> Wow, that is dedication! Congrats on getting your OTA working. I now realize how lucky I am that all my OTA comes from the same set of towers.
> 
> Just curious, did you check to make sure these four stations are keeping their same frequencies post-transition, or will you be needing to get new jointennas then?


No, I didn't check that. If they don't keep their same frequencies, I'll just order new jointennas. Maybe I'll get lucky.


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## Lee L (Oct 1, 2003)

Probably not.   but good solution.


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## vertigo235 (Oct 27, 2000)

For me, all the towers are for the most part in the same direction, I just have 2 a bunch closer than the others (and more powerful). 

Instead of usign 3 antennas, why couldn't I just split the signal from the antenna and then attenuate prior to going into the jointenna for the more powerful stations? Would this work?


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## newsposter (Aug 18, 2002)

chris_h said:


> Wow, that is dedication! Congrats on getting your OTA working. I now realize how lucky I am that all my OTA comes from the same set of towers.
> 
> Just curious, did you check to make sure these four stations are keeping their same frequencies post-transition, or will you be needing to get new jointennas then?


this should help with 2nd round choices

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-05-2649A2.pdf


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## thecrave (Dec 3, 2004)

Anyone aware of other alternatives? 

I have a problem with multipath on my NBC station (33), but I'm afraid if I get a Join-Tenna that I will block out UPN & WB. My expectation would be to order a Join-Tenna for 33, connect my 40" boom below to the Join-Tenna at All Stations, then take the output and put it into a combiner with my DB2 Multidirectional antenna in order to avoid having more antennas (antennae?)  

I'm in zip 14075 and I have the following setup:

40" boom antenna from Radio Shack pointed at 358 degrees for the following channels

Apx 358 Degrees
14 - FOX
32 - UPN
43 - PBS

DB2 Multidirectional antenna pointed at 101 degrees

Apx 100 / 87 Degrees
33 - NBC
34 - WB

Apx 127 / 121 Degrees
38 - ABC
39 - CBS


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## Indiana627 (Jan 24, 2003)

OK, I'm more than just a little confused. I'm also in the Buffalo area and for me the towers are:

ABC - 169° 38 frequency
CBS - 169° 39 frequency
NBC - 160° 33 frequency
Fox - 243° 14 frequency
PBS - 243° 43 frequency
CW - 243° 32 frequency
MNT - 243° 34 frequency

I have a Terk multi-directional amplified antenna (model TV-5) setting on top of my entertainment center. All of these channels come in fine on my Sony A10 TV. With the HR10, I get the 169° channels fine, but have problems with the 160° and 243° channels. 

What exactly would I need to buy/rig up to get the 160° and 243° channels to come in? In order of preference, I'd like to be able to get on my HR10 (without harming the 169° channels):

NBC - 33 frequency
Fox - 14 frequency
PBS - 43 frequency
CW - 32 frequency
MNT - 34 frequency

My current antenna setup is: antenna to splitter; from splitter I have 1 line going to TV and 2 going directly to the HR10's internal tuners. I bypassed the HR10's splitter after reading that can help but it didn't for me.

Thanks.


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## sluciani (Apr 21, 2003)

wozman57 said:


> I'm using one antenna to get both NBC and CBS becuse they are located in the same direction and the frequencies are so close together.


Guess I'm not uderstanding why you need two antennas for ABC & Fox if they're both at 164 degrees. TIA for explaining. /steve


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## Indiana627 (Jan 24, 2003)

Anyone?


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## newsposter (Aug 18, 2002)

i'd try buffalo for help

http://www.avsforum.com/avs-vb/showthread.php?t=137214



sluciani said:


> Guess I'm not uderstanding why you need two antennas for ABC & Fox if they're both at 164 degrees. TIA for explaining. /steve


the post says
ABC - 169° 38 frequency
CBS - 169° 39 frequency
NBC - 160° 33 frequency
Fox - 243° 14 frequency

so fox is a different direction

good thing fox isn't a 13 or he'd really have fun


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## Sir_winealot (Nov 18, 2000)

newsposter said:


> i'd try buffalo for help


"Tatonka!?"


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## Indiana627 (Jan 24, 2003)

newsposter said:


> i'd try buffalo for help


Yes, I follow that thread but since the solution was posted here I thought I'd ask for help here.


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## sluciani (Apr 21, 2003)

newsposter said:


> i'd try buffalo for help
> 
> http://www.avsforum.com/avs-vb/showthread.php?t=137214
> 
> ...


I was replying to the first post and the information in the diagrams attached, which show both stations at 164°.

/steve


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## Lee L (Oct 1, 2003)

Well, it seems that you are getting multipath with the omnidirectional antenna. As mentioned, teh solution is to use multiple directional antennas to solve it. You might try one of the small directionals like the Zenith Silver Sensor (not sure if they are being made anymore but Terk has a copy of it now though the price is gouging IMO) or even just a $25 Rat Shack antenna to mount outside or in teh attic to see if the stations will come in using just that antenna. Then you can start using join-tennas to get everythign working together. You might be able to use the multidirectional with a small directional just to get the signals you want, but you might also need to switch to 2 directionals.

What is the terrain like between you and the transmitter?


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## Indiana627 (Jan 24, 2003)

Lee L said:


> What is the terrain like between you and the transmitter?


Between me and the 243° stations it is very flat. There are some hills between me and the 160° and 169° stations, though I have no problems receiving the 169° stations. So to use just 2 antennas, I would need a join-tenna? Is the rule that you'd need 1 less join-tenna than the number of antennas you use? And each has to be tuned to allow or block a certain frequency?


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## poppagene (Dec 29, 2001)

Indiana627 said:


> OK, I'm more than just a little confused. I'm also in the Buffalo area and for me the towers are:
> 
> ABC - 169° 38 frequency
> CBS - 169° 39 frequency
> ...


My advice would be to point one antenna to 243 (main antenna) and point 2 antennas to 169 and a fourth to 160. Get jointennas for the 33 , 38 and 39 frequencies and configure them similar to the original poster.


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## ECEGatorTuro (Jan 20, 2006)

Wow, I never knew people had so many problems receiving OTA stations. I thought most TV transmitters where all in the same location in most cities but I guess I'm wrong!

I guess I'm lucky being in Phoenix... ALL the transmitters sit on top of South Mountain!!


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## Indiana627 (Jan 24, 2003)

poppagene said:


> My advice would be to point one antenna to 243 (main antenna) and point 2 antennas to 169 and a fourth to 160. Get jointennas for the 33 , 38 and 39 frequencies and configure them similar to the original poster.


So 4 total antennas. Hmmm... I think the wife would sooner have me sitting on top of the entertainment center than to have 3 more antennas! The 3 jointennas would cost $90 + shipping, plus I'd have to get 3 more antennas. Not sure I can swing that since we have a 2 month old baby now. Plus D* just announced our local HDs are supposed to be available by the end of the year, so maybe I'll just wait for that and get the HR20. Hopefully it's OTA tuners will be active by then and hopefully they'll be more on par with with my A10 tuners than the HR10 tuners. Heck, I think I'd get the HR20 now if the tuners were active and people reported them as reliable.

Thanks for the help. At least now I know what I would need to do if I decide to do it.


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## ColdCase (Oct 13, 2006)

There is a tower directly between me (3mi) and several distant stations (35mi) that happens to transmit on both 50 and 35 (HD). All stations of interest are at a 178-180 angle. The local station plans is to eventually transition to 35 I think. 

In the mean time I'd like to block both the 50 and 35 frequencies so my preamped system doesn't get overloaded/saturated/degraded. 

It looks like these joiner type antennas can be configured to block a single frequency, and 35-50 is pretty far apart I think. If I had to choose, which frequency would be more of a problem for HDTV. I'm guessing its not that simple. 35 is closer to most of the distant channels. Wonder if they can cascade the blocks to take out both frequencies. 

In the past I used a tunable inline filter with some success, but these joiners may be a better solution for me. 

Thanks


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## poppagene (Dec 29, 2001)

ColdCase said:


> There is a tower directly between me (3mi) and several distant stations (35mi) that happens to transmit on both 50 and 35 (HD). All stations of interest are at a 178-180 angle. The local station plans is to eventually transition to 35 I think.
> 
> In the mean time I'd like to block both the 50 and 35 frequencies so my preamped system doesn't get overloaded/saturated/degraded.
> 
> ...


It's not clear to me why you need to block 50 and 35, but if that's what you are trying to do, you can get 2 jointennas , 1 for 50 and one for 35 and cascade them. The setup is similar to that of OP except that you'll ony need one antenna.

the setup goes: main antenna into all channels input on jointenna for 35 (best to get a terminator cap for the channel 35 input) >>> output goes to the all channels input for channel50 jointenna (again it's probably best to put a terminator cap on the channel 50 input) and the out put runs to your tivo or tv as an OTA antenna without frequencies 35 or 50.


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## Runch Machine (Feb 7, 2002)

wozman57 said:


> I was one of those that thought the OTA tuner in my HD Tivo was broke ... because with my $60 Radio Shack antenna in the attic hooked up to the tuner in my Sony 50' A10 HDTV, all the HD stations came in fine ... but when hooked up to my HD Tivo, the signal quality for most frequencies would bounce from 10 to 80 from 10 to 80. Thanks to this message board, the problem was diagnosed as multipath ... and pointed me to a better antenna configuration. I called up channel master technical support, resulting in the solution attached. This should be a reference for the proper use of a pair on jointennas for a multi antenna configuration. If you are having multipath issues, and only care to receive the main 4 local networks, then I suggest you try my solution. The signal quality for all four networks show up at a constant ~92% for both tuners. All three of my channel master 4221's are mounted in my attic ... I am roughly 24 miles from all the networks I care about (where the 4221 has a range of 45 miles). Each of the three 4221's were only $20 each, where both jointenna's were $30 each. With shipping this solution cost $150 ... well worth the cost of being able to tivo my HD locals. I purchased them from www.warrenelectronics.com ... the jointenna's are special order, which takes 2 1/2 weeks to get to your door (you have to specify the frequency that you want each jointenna to be "tuned to"). For reference, a jointenna works in two ways. The specific frequency input filters all frequencies except for the one it is tuned to. The "all channels" input allows all channels to pass except for the specific frequency. Just as long as the difference between your desired filtered channels is 4-5, you could daisy chain quite a few of these together, each dedicated to a specific frequency. I'm using one antenna to get both NBC and CBS becuse they are located in the same direction and the frequencies are so close together.
> 
> The first attachement/picture shows the location of my desired networks at zipcode 28117 from www.antennaweb.org. The second attachment/picture shows my jointenna/antenna configuration.
> 
> I hope this helps those that were in the same frustrated situation as I.


I love tinkering with OTA antennas and enjoyed your post. Here's a suggestion that would reduce the number of antennas needed to two. Since 27 and 34 come from the same direction, remove one of the 4221s aimed that direction and put a splitter on the antenna to split the signal into the appropriate jointennas. What do you think of that idea?

I use one jointenna, a 4221 and an all channel antenna to pickup our local channels and another channel coming from a different direction. The Jointenna works great.


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## BuckNakd2 (Apr 19, 2006)

Runch Machine said:


> I love tinkering with OTA antennas and enjoyed your post. Here's a suggestion that would reduce the number of antennas needed to two. Since 27 and 34 come from the same direction, remove one of the 4221s aimed that direction and put a splitter on the antenna to split the signal into the appropriate jointennas. What do you think of that idea?
> 
> I use one jointenna, a 4221 and an all channel antenna to pickup our local channels and another channel coming from a different direction. The Jointenna works great.


I was wondering about a solution similar to this as well. It would cut down on the number of antennas pointed in the same direction.

My question is would the use of a splitter degrade signal to a noticeable degree? and if you use a preamplifier where does it fit into the diagram? If it is placed after the jointennas/splitters then wouldn't it be amplifying a weakened signal and if it's placed at the antenna before the jointennas/splitters would you need multiple preamps?


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## poppagene (Dec 29, 2001)

Indiana627 said:


> So 4 total antennas. Hmmm... I think the wife would sooner have me sitting on top of the entertainment center than to have 3 more antennas! The 3 jointennas would cost $90 + shipping, plus I'd have to get 3 more antennas. Not sure I can swing that since we have a 2 month old baby now. Plus D* just announced our local HDs are supposed to be available by the end of the year, so maybe I'll just wait for that and get the HR20. Hopefully it's OTA tuners will be active by then and hopefully they'll be more on par with with my A10 tuners than the HR10 tuners. Heck, I think I'd get the HR20 now if the tuners were active and people reported them as reliable.
> 
> Thanks for the help. At least now I know what I would need to do if I decide to do it.


based on Runch Machine's post I believe you can get by with 3 antennas and a splitter -- split the 169 degree antenna and cascade the split signals through the 38 and 39 jointennas. You could get by with 2 antennas and 2 jointennas if you are willing to give up on 33 or maybe 2 antennas and 3 jointennas and a 3 way splitter on the 2nd antenna if you can get 33, 38 and 39 on the same antenna.


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## internetuser (Feb 17, 2009)

Using a coax splitter with two antennas may work just as well; search google for hdtvprimer merging feedlines.


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## litzdog911 (Oct 18, 2002)

internetuser said:


> Using a coax splitter with two antennas may work just as well; search google for hdtvprimer merging feedlines.


There is a big difference between the JoinTenna and a simple coax splitter/combiner.


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