# OTA issues! :(



## ECEGatorTuro (Jan 20, 2006)

Hello everyone!
I have been trying to figure out this problem since last week and I don't know what to try any more so I figured maybe someone can help me.

I have watched all of my network HD channels OTA for almost a year now without any problems. I use some rabbit-ears that are propped up on my roof right now facing the general direction of South Mountain here in Phoenix (where ALL of the TV and radio antennas sit on).

Right around last week, I noticed that my recordings of 24 and American Idol were so corrupt that the Tivo only recorded a few minutes of each episode before it gave up. I went to the OTA signal strength meter in the setting menu and the signal I am receiving for Fox was bouncing all over the place but mostly staying under 50. All of the other network channels are coming in steady and solid around 85-95. Nothing has changed in my setup!! I tried rebooting the Tivo and that didn't solve anything.

Does anyone have ANY idea what could be causing this? Can anyone here from the Phoenix area confirm that the transmission from KSAZ 10.1 is broadcasting good (or bad)? It has been going on for at least a week now so I can't seem to think that it's the broadcast.


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## litzdog911 (Oct 18, 2002)

Doublecheck your coax cable connections at the antenna. Also be sure that nothing is loose, wet or corroded up there. 

What type of "rabbit ears" did you use? Most of them are not designed for outdoor mounting.


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## kdonnel (Nov 28, 2000)

Have the trees started budding out in your area?

I have finally found a position for my antenna that works during the transition from Winter to Spring and from Summer to Fall. 

I had lots of problems with my signal strength caused by the appearance or disappearance of the leaves primarily on just one of my channels. In my case it was WSB(ABC) digital channel 39.

Try to reposition your antenna.


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## JimSpence (Sep 19, 2001)

This is caused by what is called "multipath". It is analogous to ghosting in the analog world and prevents the ATSC (digital) tuner from locking on.


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## Markman07 (Jul 18, 2001)

Does your tv have a built-in tuner? Bypass the Tivo and see if the signal meter is still bouncing around.


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## Indiana627 (Jan 24, 2003)

I feel your pain. When I hook my antenna up to my TV, all my local HD channels come in great. When I hook same antenna up to my HR10, only 2 come in great, 2 more are so-so and 3 others are very hit and miss (miss mostly). Very frustrating.


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## JimSpence (Sep 19, 2001)

It is known that the ATSC tuner in the HR10 is not as good as the one in the TV. Heck, my DirecTV non-DVR HTL-HD receiver does a better job.


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## TyroneShoes (Sep 6, 2004)

I have it from unimpeachable sources that nothing has changed regarding the nature of the broadcasts from that station.


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## ECEGatorTuro (Jan 20, 2006)

Thanks for all of the input everyone!

I haven't had a chance to move the antenna around yet since I've been pretty busy but I'll give it a shot this weekend. I'll let you know if it worked or not. Thanks!!


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## pmyers (Jan 4, 2001)

Indiana627 said:


> I feel your pain. When I hook my antenna up to my TV, all my local HD channels come in great. When I hook same antenna up to my HR10, only 2 come in great, 2 more are so-so and 3 others are very hit and miss (miss mostly). Very frustrating.


THANK YOU!!! I knew I wasn't crazy. I just hooked up my new HR10-250 last night and all of a sudden my OTA reception went to crap compared to just going through the TV. Is there any way around this?

To the OP: I live in Gilbert and Fox gives me the worst reception by far. I use a powered indoor antenna.


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## temp357 (Feb 18, 2004)

ECEGatorTuro said:


> Hello everyone!
> I have been trying to figure out this problem since last week and I don't know what to try any more so I figured maybe someone can help me.
> 
> I have watched all of my network HD channels OTA for almost a year now without any problems. I use some rabbit-ears that are propped up on my roof right now facing the general direction of South Mountain here in Phoenix (where ALL of the TV and radio antennas sit on).
> ...


Go back to 3.1.5f and i'd bet the problems go away. I had the same problem when i upgraded to 6.3a


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## TyroneShoes (Sep 6, 2004)

pmyers said:


> THANK YOU!!! I knew I wasn't crazy. I just hooked up my new HR10-250 last night and all of a sudden my OTA reception went to crap compared to just going through the TV. Is there any way around this?...


Since your question is broadly stated, permit me to give a general response.

As Jim and others state, reception from the HR10 tuner is usually not as good as your garden-variety late-model HDTV tuner. Other than changing the transmit pattern, the reflectiveness of your environment, or the distance you are from the towers (all pretty much out of your control) that leaves a better tuner (again out of your control on the HR10) or a better antenna system.

That would include small but sometimes effective improvements such as attenuators, FM traps, preamps, and reaiming, to replacing the antenna and placing it higher and outside. For this location, a CM 4228 would be ideal, and would be the first big step I would try, after trying all of the little steps.


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## JimSpence (Sep 19, 2001)

One warning about using the 4228. It won't work if you have digital stations in the low VHF band (2-6) and may be iffy for the other VHF channels.


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## ECEGatorTuro (Jan 20, 2006)

So I keep hearing about the OTA tuner in the HR10 sucking but I don't want to plug it into my TV tuner since I record the majority of my HD shows on it. I'm going to try and work on re-positioning my antenna tonight or tomorrow.

pmeyers, I currently live in Gilbert right now (by Pecos and Gilbert) and I will be moving farther away in the summer to Sun Groves (Riggs & Lindsey). I was just wondering what type of powered antenna are you using and how does it work?

I've never had experience with antennas before so I don't know what type to get. Lucky for us that all of the signals come from South Mountain so it makes it much easier to point!


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## TyroneShoes (Sep 6, 2004)

JimSpence said:


> One warning about using the 4228. It won't work if you have digital stations in the low VHF band (2-6) and may be iffy for the other VHF channels.


Not sure who you are warning or why, but the original poster is in an area with no VHF DT channels, which is why the recommendation was for the 4228, which also happens to work exceptionally well for channels 7-13.


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## TonyD79 (Jan 4, 2002)

Okay, I am a bit confused.

The channels are all UHF (according to TyroneShoes) but the OP says he is using "rabbit ears?"

Rabbit ears are for VHF typically. I would assume that it is a rabbit ear/loop combo but I don't like to assume anything.


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## ECEGatorTuro (Jan 20, 2006)

TonyD79 said:


> Okay, I am a bit confused.
> 
> The channels are all UHF (according to TyroneShoes) but the OP says he is using "rabbit ears?"
> 
> Rabbit ears are for VHF typically. I would assume that it is a rabbit ear/loop combo but I don't like to assume anything.


Actually, it is litteraly a pair of old rabbit ears.... the type of antenna you would use on the old style TV. Does that mean I receive VHF signals?

Aren't the lower channels (the network channels) in VHF? I'm not clear as to the difference between VHF and UHF. Isn't VHF the lower channels and UHF the higher channels? I remember back in the day that VHF channels were usually below channel 30-something and UHF were above that range.

The frequencies for the channels in the Phoenix area are as follows:
FOX - 10.1 - 31
CBS - 5.1 - 17
NBC - 12.1 - 36
ABC - 15.1 - 56

If I understand this right, does that mean I would need a VHF/UHF antenna? If so, then how come I've been receiving all of these channels on the plain rabbit ears (no loop)?

Thanks for all your help!


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## phox_mulder (Feb 23, 2006)

ECEGatorTuro said:


> The frequencies for the channels in the Phoenix area are as follows:
> FOX - 10.1 - 31
> CBS - 5.1 - 17
> NBC - 12.1 - 36
> ...


All those frequencies are UHF, you'll recieve them better with a UHF antenna.
31, 17, 36, 56 are UHF.

VHF is 2-13, UHF 14-60+

Rabbit ears can get UHF frequencies, jut not as well as an antenna made for UHF.

phox


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## HomieG (Feb 17, 2003)

ECEGatorTuro said:


> Actually, it is litteraly a pair of old rabbit ears.... the type of antenna you would use on the old style TV. Does that mean I receive VHF signals?
> 
> Aren't the lower channels (the network channels) in VHF? I'm not clear as to the difference between VHF and UHF. Isn't VHF the lower channels and UHF the higher channels? I remember back in the day that VHF channels were usually below channel 30-something and UHF were above that range.
> 
> ...


Looks like the digital signals are all on UHF. The VHF channels x.1, denote that they are mapped, basically for recognition, to the old VHF channel numbers so you know what local you are tuned to. When tuned to the DTV/digital channel, those are all UHF as noted in your post. And that's where the HD signal will be if the show is being broadcast in HD.

The rabbit ears can work if you're close enough to the transmitters (and so can a paper clip in some cases), but the received signal isn't optimal. The Fox channel may be transmitting at a lower power, antenna height, or further distance from you, or the rabbit ears may not be terribly effective at Channel 31, versus the other channels.

BTW, for US television broadcasts, VHF channels are 2-13. UHF channels are (currently) 14-69.

Thanks for all your help!


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## ECEGatorTuro (Jan 20, 2006)

Ok, that makes much more sense now!

I'm guessing the Fox transmitter is either lower power or my antenna just sucks for that frequency because all of the TV transmitters sit in the same place in the city.

So I'm guessing that 4228 antenna would work for me then?


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## JimSpence (Sep 19, 2001)

I responded the way I did about the 4228 because nowhere in the replies was it mentioned what frequencies the OP was trying to receive. It was also meant as a general statement for others that may read this thread. 

And for the OP, the 4228 should work very well as you need its directionality.


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## JohnnyO (Nov 3, 2002)

ECEGatorTuro said:


> Ok, that makes much more sense now!
> 
> I'm guessing the Fox transmitter is either lower power or my antenna just sucks for that frequency because all of the TV transmitters sit in the same place in the city.
> 
> So I'm guessing that 4228 antenna would work for me then?


If Rabbit ears almost work fine, you could probably get by with something smaller than the CM 4228, such as the CM4221.

http://www.hdtvprimer.com/ANTENNAS/cm4221.html

http://www.hdtvprimer.com/ANTENNAS/cm4228.html


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## TonyD79 (Jan 4, 2002)

JimSpence said:


> I responded the way I did about the 4228 because nowhere in the replies was it mentioned what frequencies the OP was trying to receive. It was also meant as a general statement for others that may read this thread.
> 
> And for the OP, the 4228 should work very well as you need its directionality.


Yeah. It all confused me so I went to antennaweb to get the Phoenix stations.

Glad my confusion cleared things up, what?


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## TyroneShoes (Sep 6, 2004)

phox_mulder said:


> ...Rabbit ears can get UHF frequencies, jut not as well as an antenna made for UHF...


Right you are.

But the issue is probably not how rabbit ears, being tuned for lower frequencies, won't transfer as much signal to the tuner as a UHF antenna (tuned exactly for those frequencies) will, as much as it is about how a highly-directional antenna such as the 4228 will cut through the multipath interference better, which is really probably what's causing the bad reception.

Rabbit ears have a +3 dB gain factor at 0 degrees and also at 180 degrees, so are only slightly directional and have a lousy front-to-back ratio. The 4228 has about 12 dB of gain in one direction only. The vertical beamwidth of the 4228 is also very tight, while rabbit ears (a folded dipole) has no real vertical beamwidth (IOW, it receives just as strongly from straight up or down as it does straight to the front and back directions).

But multipath aside, ironically enough, the 4228, designed for UHF, will probably deliver more signal at VHF than typical rabbit ears will anyway, just by virtue of its higher gain, making it a better antenna for VHF DT than rabbit ears simply by virtue of gain alone.


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## ECEGatorTuro (Jan 20, 2006)

The 4228 antenna seems pretty big! Is this a type of antenna I can hide somewhere in an attic or other location and still pick up a good signal? Guesstimating my distance to the transmitter towers, I would say I'm about 18-23 miles away and I'm in a two-story house.


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## spankspank (Nov 7, 2000)

ECEGatorTuro said:


> The 4228 antenna seems pretty big! Is this a type of antenna I can hide somewhere in an attic or other location and still pick up a good signal? Guesstimating my distance to the transmitter towers, I would say I'm about 18-23 miles away and I'm in a two-story house.


It might work in your attic. You may need to add a pre-amp.


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## Sir_winealot (Nov 18, 2000)

ECEGatorTuro said:


> The 4228 antenna seems pretty big! Is this a type of antenna I can hide somewhere in an attic or other location and still pick up a good signal? Guesstimating my distance to the transmitter towers, I would say I'm about 18-23 miles away and I'm in a two-story house.


I have the 4228, and I'm 29.3 miles from the towers (ABC/NBC/FOx), with my CBS affiliate 10 miles away in the _opposite_ direction...it works very well for me.

We have the antenna hanging from a couple nails on some attic trusses (2 story house).

We're also surrounded by tall trees, so although we got a strong signal on all channels (88+), we experienced a bit of multipath which was solved by simply moving the 4228 into another location about 12 feet away.

It should be more than ample for 18-23 miles....


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## okoaomo (Apr 13, 2006)

I have a CM 4221 in the attic of my single story garage. It does a great job @ $25 from solidsignal you can't beat it. I have it on an eagal aspen single wire rotater. This is due to having NBC @ 18 miles, ABC @ 18 Miles, CBS @ 5 miles in the west and PBS @ 32 miles, CW @ 19 miles, MNT @ 19 miles in the east. I only record from the west stations, so that is where I leave it set unless I want to watch the others. I dont' use a preamp, and I get 80+ on all but PBS wich is 50 to 60, but it works just fine.


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## TyroneShoes (Sep 6, 2004)

ECEGatorTuro said:


> The 4228 antenna seems pretty big!...I'm about 18-23 miles away...


"Big" is a relative term. Many RatShack antennae are 16 ft long and half as wide. The 4228 is what, 45" by 39" and 5" thick? Sounds perfect for an attic, assuming no metalized insulation or aluminum siding.

I'm 21 miles away from the very same towers, and I get perfect reception on the 79-cent FM antenna that came packed with my AVR, taped to a window, which proves that if you have minimal multipath, any antenna will do.

But, you can't have an antenna with too much directionality, assuming you have a single target to be concerned with. And if you have multipath, the strategy is a more-directional antenna. Of course with increased directionality comes increased gain, so at this distance a hotter antenna could overload a DTivo. Be sure to try whatever "better" antenna you end up with in concert with a variable attenuator for best results.


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## khark (Jan 2, 2001)

Here are the channels and distances from the transmitters to my house: 9=91.64 mi., 17=91.62 mi., 23=68.32 mi., 36=91.63 mi.

I have a CM 4228 antenna and also an older VHF antenna both running through a CM 7777 amplifier. Of course I have a rotator. The 3 that are 91+ miles are on the same mountaintop so I can leave the antennas pointed the same to get all of them.

Interestingly I can't get any signal at all from the station that is 68 miles away no matter where I point the antenna.

I have the west coast feeds from DirecTV but I thought I would try the antenna just to see if it was possible to get OTA reception from nearly 100 miles away. Well it is but I don't really worth the money for the antenna, etc. but at least I know it is possible.


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## okoaomo (Apr 13, 2006)

khark said:


> Interestingly I can't get any signal at all from the station that is 68 miles away no matter where I point the antenna.


Look up the call letters for that station on this FCC site.

http://www.fcc.gov/fcc-bin/audio/tvq.html

compare the ERP of that station with the ERP of your other stations.
My guess would be that it is a low power antenna like a DSB or TLP.
You can also look at the Azimuth pattern and determin if you fall within it.


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## khark (Jan 2, 2001)

okoaomo said:


> Look up the call letters for that station on this FCC site.
> 
> http://www.fcc.gov/fcc-bin/audio/tvq.html
> 
> ...


The one I don't pick up is the highest ERP of any of them at 505kw ERP compared to Channel 9=17.9 kw ERP 
Channel 17=189kw ERP 
Channel 36=200kw ERP

Looking at the coverage area maps I fall outside of all the area by a long way.


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## TyroneShoes (Sep 6, 2004)

There are two reasons why you can't get a particular channel (assuming all is well and you are tuning to the physical channel number), either the signal level is too low at the point of reception, or the multipath ratio is too high. (we'll ignore "too strong" because that is unlikely at 68 miles). We have pretty much ruled out too low of a signal level, so you may have a terrain obstruction or other issue that is causing a high multipath ratio. You already have the best antenna/preamp combo for distant DT reception in the 4228/7777, so it would be difficult to improve the antenna system.

Unless:

You mention not only the 4228 but also a VHF antenna. The 4228 (assuming the two rear screens are firmly bonded together, which is easy to do) will work exceptionally well for high VHF such as ch 9, so the VHF antenna is probably not needed. Also, if you combine both antennae into one downlead, what you are effectively doing is destroying the directionality of the system, making the antennae less efficient and less directional.

There are ways to combine such antennae that can work in particular situations, but it is tricky and hit-or-miss. In your situation, removing the VHF antenna is probably a good idea, since it is not needed. That would certainly maximize multipath rejection, so is probably worth a try and has a high probability of success.


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## khark (Jan 2, 2001)

TyroneShoes said:


> Unless:
> 
> The 4228 (assuming the two rear screens are firmly bonded together, which is easy to do) will work exceptionally well for high VHF such as ch 9, so the VHF antenna is probably not needed.


How do I easily firmly bond the two rear screens? Do I use some kind of clamps or just wire them together?


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## TyroneShoes (Sep 6, 2004)

I just took a 2-inch chunk of #10 electrical wire and twisted it around the edges of both screen-halves with a lineman's pliers. I actually did that in 4 places and then gave each a coating of LPS3 to prevent corrosion. There are details on this subject at www.hdtvprimer.com, although I'm not sure of that person's technique.

(in light of the "Leila" investigation, sharp-eyed posters might remember I also claim to be receiving DT just fine using only a piece of twinlead taped to a window. Actually, both scenarios are true, one at home and one at work.)


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