Moved about 1 mile south and lost 2 channels [Archive]

sdubb

25-Apr-2011, 11:19 PM

Well I had my antenna all setup at my old place and never had a problem. I received all my channels on my TV and my HTPC (Dual HDHR Tuner)

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d8d179f772c313e

Now I have moved about a EDIT 2 miles south and I dont see any major obstacles in the path. The height has not changed (still on the same pole)

I can not get ABC (15.1) or this kids channel (51.2) all the other come in just fine.

3.1 Works
5.1 Works
8.1 Works
10.1 Works
12.1 Works
15.1 Does not work
45.1 Works
51.2 Does not work
61.1 Works

Those are the channels I am after. Here is my NEW setup
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d8d17890fde99e8

I wish I new what kind of antenna I had. I can post a picture of it when I get home but its HUGE. Its the old style and probably about 8' long.

Any help greatly appreciated.

GroundUrMast

26-Apr-2011, 12:40 AM

It looks like the hills adjacent to Casa Grande park are blocking your view toward South Mountain (Salt River Mountains) were the transmission towers are located. The elevation in the Arizona City area is about 1500' MSL. The peaks of the Casa Grande hills are over 2200' MSL. That means that you could build a 500' tower and still be blocked by terrain.

Click on the call sign of a station of interest in your TV Fool report and you will see a cross sectional view of the path profile. KPPX-DT (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d8d17890fde99e8%26t%3dALLTV%26n%3d23) for example.

You are going to need a high gain combination antenna to see KPPX which is the lowest in strength. I would suggest the Antennas Direct XG91 and a Winegard YA-1713 joined with a Antennacraft 10G221 preamplifier. KNXV-DT is likely being effected by lower signal level, compared to your former location and I suspect, multipath. The higher gain and sharper directivity of the XG-91 is the best hope of overcoming both of those problems. Regardless of the obstructing terrain, a reasonable and safe effort to mount high and in the clear will likely offer a bit of signal improvement.

Antennas such as the Winegard HD7698P are a second best option in terms of gain on channel 51. The advantage of the Winegard would be one less antenna. But giving up 2 dB of gain when you are on the edge would risk making reception of KPPX less reliable.

John Candle

26-Apr-2011, 12:58 AM

What is the height of the antenna?? South Mountain is at 320 degree magnetic compass from your location. Point your Tv antenna at South Mountain. Here is how to point Tv antennas , http://www.kyes.com/antenna/pointing/pointing.html . . Read and understand this about , REAL Digital Tv Channels , Virtual Digital Tv Channels , Analog Tv Channels , http://forum.tvfool.com/showthread.php?t=695

John Candle

26-Apr-2011, 12:59 AM

What is the height of the Tv antenna??

John Candle

26-Apr-2011, 1:04 AM

Of the antennas pictured in pointing the antenna link , what antenna looks the most like the one you have. Before buying new antennas we can work with the one you have.

sdubb

26-Apr-2011, 3:33 AM

The one that looks most like what I have is " all band uhf vhf fm" but the sides dont go straight out they angle.
Like I said I didn't have any problems with it at the old place.
The height is about 12 feet.

John Candle

26-Apr-2011, 4:28 AM

If you will send me a private message with your exact address I can be of more help.

sdubb

26-Apr-2011, 5:42 AM

If you will send me a private message with your exact address I can be of more help.
Just did it :D

John Candle

26-Apr-2011, 4:32 PM

Ok thanks for the old and new exact address. . The reception at your new location is not as good because of the ways that the Tv transmissions scatter and bend across the Casa Grande regional park mountains to the north. . At the >Start MAPS< part of tvfool you can test different locations on the property. Move the antenna around and up and down. It looks like the strongest signal for KPPX is with the antenna about one foot above the ground. . 0 NM(dB) is the reference signal power number for reliable reception. Negative 10 NM(dB) is about the lowest receivable signal strength and Plus 4 NM(dB) for KPPX is a weak signal. Antenna gain gives more positive numbers to the signal power. . When the NM (dB) numbers get up in to the 20's , 30's , 40's , 50's , 60's thats better. . GM is correct with the 2 antenna , preamp solution. And for the phoenix stations the antenna or antennas will need to be pointed at the tops of the mountains to the north. Also do not block the front of the antenna or antennas with fences or walls or buildings. The antenna/s must be free of obstructions. Probing with a antenna or antennas is the best way to find hot spots on the property.

sdubb

26-Apr-2011, 4:56 PM

GroundUrMast

26-Apr-2011, 5:16 PM

I had a little time to play with the antenna. Shooting right at South Mountain (how it is installed now) I am able to receive the channels I posted. If I turn the antenna toward the east I am able to pickup channel 15.1 (really want this channel)

The little that I read. Combine to antennas with a reverse splitter. (I think thats what its called) Is that what you guys are talking about?

The XG-91 is a large high gain UHF only (real channels 14-69) antenna. The YA-1713 is a large high gain H-VHF (real channels 7-13) antenna. These would replace your existing antenna. Combining the output of each is best done with a frequency sensitive devise called a diplexer, specifically a UVSJ. The 10G221 preamplifier has the UVSJ built in. A common splitter can be used to combine multiple signals but will attenuate the signals from both antennas and will permit undesired interaction between the two antennas. The 10G221 preamplifier also has a switchable FM filter which may be needed to reduce interference from some of the stronger FM stations.

Given the narrow profile of the Casa Grande hills, it's not surprising that you would see signal diffracting around them. Fine tuning your aim point is certainly worth the effort.

sdubb

26-Apr-2011, 5:25 PM

GM thanks for the information. I am slowly learning, I have always lived in Phoenix so I didnt need anything to crazy to get channels, now that I am 50 or so miles away its a whole new ballgame.

So does that mean even with the 2 antennas you have posted I will still lose channels 3.1 and 5.1?

Man this is so confusing. Is there a thread that has the basics that I missed when I signed up?

Thanks again for all the help guys.

GroundUrMast

26-Apr-2011, 5:34 PM

So does that mean even with the 2 antennas you have posted I will still lose channels 3.1 and 5.1? I don't think so. I expect the antennas I'm suggesting will give you a very good chance at restoring the channels you lost when you moved into the shadow of the Casa Grande hills.

Virtual channel 3.1 is KTVK, real channel 24. VC 5.1 is KPHO, real channel 17. I'm reasonably confident that the added gain of the XG-91 will gather enough additional signal for you to get reception of these two stations without losing access to KNXV. I also expect this antenna to give you a good shot at restoring access to KPPX.

The H-VHF antenna will receive real channels 8,10 and 12. Channel 13 is on the back side of the antenna and may or may not be received.

sdubb

26-Apr-2011, 5:50 PM

Okay thanks, this is starting to make sense now. I was jumping back and forth looking at real channels and virtual channels.

I totally understand why John makes it a point to post about the whole channel thing. What a mess :confused:

I really like how you have it broken down for me. I guess I was just hoping for a all-in-one antenna that would get both sides. I dont need 13 so I am not worried about that channel.

I still dont understand how the 10G221 works? Does it plug into the wall? I need to read up some more on that little device.

GroundUrMast

26-Apr-2011, 5:53 PM

I still dont understand how the 10G221 works? Does it plug into the wall? I need to read up some more on that little device.

It will need power. It's a two part system. The power supply is designed to be indoors and will 'insert' power into the coax leading up to the antenna. The amplifier unit will be mounted on the mast near the antennas.

http://www.antennacraft.net/Antennas/AntennaAmplifiers.html

http://www.winegard.com/offair/vhf-antennas.php

http://www.antennasdirect.com/store/91XG_HDTV_Antenna.html

In some cases the manufactures' web site is the best place to buy, in other cases you can find retailers with better prices.

Some of the very large all-in-one antennas approach the performance of the antennas I'm recommending but none have quite the UHF gain of the XG-91... which you will need to make reception reliable.

sdubb

26-Apr-2011, 6:16 PM

Okay like POE (power over ethernet)?

So I will not have to run power, or another coax out to the 2 antennas?

Everthing can come down that single coax how it is now?

GroundUrMast

26-Apr-2011, 6:18 PM

Okay like POE (power over ethernet)?

So I will not have to run power, or another coax out to the 2 antennas?

Everthing can come down that single coax how it is now?
Yes to all three.

mtownsend

26-Apr-2011, 8:11 PM

I have always lived in Phoenix so I didnt need anything to crazy to get channels, now that I am 50 or so miles away its a whole new ballgame.

It looks like the hills adjacent to Casa Grande park are blocking your view toward the Salt River Mountains were the transmission towers are located. The elevation in the Arizona City area is about 1500' MSL. The peaks of the Casa Grande hills are over 2200' MSL. That means that you could build a 500' tower and still be blocked by terrain.

In open terrain, even 50 miles is usually easy to deal with. In most cases, you can go up to about 60-70 miles before you start running into horizon (curvature of the Earth) problems.

However, as GroundUrMast correctly pointed out, your signal appears to be weaker because you've moved deeper "into the shadows" of the local mountains. Perhaps the following pictures of your zip code (85223) will help you visualize what is happening (blue is weak signal, and violet is very weak signal):

KAET (RF 8, virtual 8.1)
http://forum.tvfool.com/attachment.php?attachmentid=182&stc=1&d=1303847566

KNXV (RF 15, virtual 15.1)
http://forum.tvfool.com/attachment.php?attachmentid=183&stc=1&d=1303847566

KPPX (RF 51, virtual 51.1)
http://forum.tvfool.com/attachment.php?attachmentid=184&stc=1&d=1303847566

You'll notice that at the edges of the "shadows", even a small change in location can result in a big change in signal strength.

The good news is that with GroundUrMast's suggestions, you should be able to make up the difference with a high gain antenna and pre-amp.

sdubb

26-Apr-2011, 10:00 PM

WOW! Thanks mtownsend!

When we first moved down here I thought no way I could get OTA. With the distance and Casa Grande Mountain. I saw everybody else had antenna's and a guy I knew was moving out so he said I could take his. I put it up and happily was watching all my analog TV shows. Flash Forward to digital era we moved 100 yard west, and all my digital stations were working great.

Now flash forward to today. Moved 2 miles south and well... you know where I am at now.

Those images are pretty neat and really does depict the situation.

I might have to live with what I have until I can scrape some cash. I dont really have $200 for OTA right now. We can live without 51.2 but I cant live with out ABC. I think I will just have to go the route of online streaming for my ABC fix.

sdubb

26-Apr-2011, 10:02 PM

It looks like the hills adjacent to Casa Grande park are blocking your view toward the Salt River Mountains were the transmission towers are located. Just incase somebody needs help in the same area. Its actually South Mountain in Phoenix not Salt River Mountains.

sdubb

29-Apr-2011, 6:58 PM

GroundUrMast

29-Apr-2011, 7:04 PM

Okay before I start throwing all kinds of money at this, It seems like there really is no other way to test things out. Is that what everybody is doing? Buying an antenna trying it out and then if it doesnt work back to the drawing board.

Now if I understand this right, I can buy the XG-91 and the 10G221 and with this setup I "should" be able to get my missing channels? Can I still use my exisitng antenna since I am able to get all my VHF channels.

I would rather not have to purchase another antenna strictly for VHF (7-13)

You have already demonstrated that you are right on the edge of reception of KNXV (by adjusting aim point), that gives me quite a bit of confidence that you are going to be able get KNXV. The numbers indicate the signal from KPPX is also strong enough to receive with the gain offered by the XG-91. The consumer grade alternative to the XG-91 would be a virtually identical Winegard (as measured by gain). After that you would need to look into commercial antennas or a site-built rhombic array, (a serious hobbyist project).

There is nothing wrong with trying to reuse your existing antenna as a VHF only antenna. Simply connect it to the VHF input port on the 10G221.

sdubb

22-May-2011, 2:58 PM

Well I got the XG-91 all setup and guess what I have channel 15 :) (Thanks Guys)

Now the real problem is that most of my channels are all sitting at about the same in signal strength (50-60) I would have thought they would have jumped a lot higher with this new high gain antenna. I still keep having a lot of breakup in my shows.

My VHF channels signal strength show in the 70-80 (they still break up also)

I have not bought the 10G221 so I am unsure what will happen when I get that. For now I have just been testing to see where my signals are at and comparing the strength of the two. I have been doing this by hooking one antenna up and recording the numbers and then switch to the other antenna and record the numbers.

GroundUrMast

22-May-2011, 3:27 PM

In addition to fine tuning the aim point, fine tuning the elevation of the antenna can have a measurable effect on signal strength and quality.

Unless the antenna and TV are right next to each other, you're going to need to consider the amplifier. The goal is to take that hard won signal from the antenna and deliver it to the tuner at a level above the noise generated inside the tuner(s).

sdubb

24-May-2011, 6:14 PM

GroundUrMast

24-May-2011, 6:32 PM

So the amplifier will only take the signal it has and boost it down the cable correct? The amplifier does not give the antenna any boost just the cable?

I was thinking that if this is the case... I could use a short RG6 connected to my antenna and my HDHR on the roof and see what my signal strength is using my laptop.

I guess I am curious what kind of gain I will receive with a very short cable.

I am only feeding the HDHR, no other TV's.

Generally, yes. Because I don't know the noise figure of the tuner in the HDHR, I have to say 'I don't know' whether a high quality (low noise) amplifier will buy you a few dB of real NF over-all. For example, if the NF of the tuner is 10 dB and the NF of the amp is 3 dB, you could improve matters by as much as 7 dB (theoretically).

Bottom line, you won't hurt anything to try the HDHR right at the antenna.

Amplifiers never remove noise or distortion...

ADTech

24-May-2011, 6:33 PM

An amplifier only boosts whatever signal is coming off the antenna, less losses for connectors and the amplifier's noise figure (typically around 2 dB). It doesn't make the antenna any "stronger", per se, but it can be very beneficial in cases where weak signals are otherwise lost in the cabling, distribution system, and the TV tuner's noise figure (6-10 dB typ.).

Keep in mind that the integrated "signal meters" are rarely showing the signal power of the input signal. Generally, they are a proprietary combination, of signal power, AGC voltage, and signal decoding quality.

GroundUrMast

25-May-2011, 5:13 AM

Are you reporting the signal strength indicated by the HDHR Config (GUI) utility?

Is your VHF antenna combined with the XG-91? If so, how?

Have you optimized the point of aim, antenna tilt and experimented with elevation of the antenna? The XG-91 is very directional and you need to have put every reasonable effort into putting it on target.

You said earlier that you had not purchased an amplifier yet. For the money, Antennas Direct CPA-19 and PA-18 beats all but the very expensive special order preamps for noise figure. In this case the published numbers for the 10G221 are about 1 dB worse... not a lot, but if you have not spent money on an amp yet...

The CPA-19 has better tolerance to high input levels than the PA-18. I did not suggest either amplifier earlier, because neither has separate VHF and UHF inputs. Both AD amps are capable of UHF and VHF but will require an inexpensive external UVSJ.

Because you are 'on the edge' I would revise my preamp suggestion from the 10G221 and suggest the CPA-19. Yours may be a case were every dB of noise figure is going to count.

The down side is that you may need a separate amp for VHF signals. I would try 'amping' the UHF antenna alone. Joining the two antennas with the UVSJ UHF port on the output side of the preamp.

All of this after you have searched for the very best aim, nose tilt and antenna mounting elevation.

sdubb

25-May-2011, 6:09 PM

Are you reporting the signal strength indicated by the HDHR Config (GUI) utility? Yes
Is your VHF antenna combined with the XG-91? If so, how? I dont have a proper way to combine them so I have just been disconnecting and reconnecting to see where I was sitting at. I tried to combine it with a splitter to see what would happen but that didnt work, it seemed to only be using my VHF/UHF antenna. Basically I lost channel 15 when I used the splitter.
Have you optimized the point of aim, antenna tilt and experimented with elevation of the antenna? Yes The XG-91 is very directional and you need to have put every reasonable effort into putting it on target.

You said earlier that you had not purchased an amplifier yet. For the money, Antennas Direct CPA-19 and PA-18 beats all but the very expensive special order preamps for noise figure. In this case the published numbers for the 10G221 are about 1 dB worse... not a lot, but if you have not spent money on an amp yet... I will look into it

The CPA-19 has better tolerance to high input levels than the PA-18. I did not suggest either amplifier earlier, because neither has separate VHF and UHF inputs. Both AD amps are capable of UHF and VHF but will require an inexpensive external UVSJ.

Because you are 'on the edge' I would revise my preamp suggestion from the 10G221 and suggest the CPA-19. Yours may be a case were every dB of noise figure is going to count.

The down side is that you may need a separate amp for VHF signals. I would try 'amping' the UHF antenna alone. Joining the two antennas with the UVSJ UHF port on the output side of the preamp. You lost me on this one... My VHF channels are 20-30 higher than any of my UHF

All of this after you have searched for the very best aim, nose tilt and antenna mounting elevation.[/QUOTE]

GroundUrMast

25-May-2011, 6:45 PM

You lost me on this one... My VHF channels are 20-30 higher than any of my UHFTake a look at this drawing...

Here is an example of a UVSJ (http://www.solidsignal.com/pview.asp?mc=03&p=UVSJ&d=Pico-Macom-UVSJ-UHF-VHF-Band-SeparatorCombiner-for-Antenna-%28UVSJ%29&c=Signal%20Combiners&sku=)

If you have solid reception of all you VHF stations, don't spend money amplifying them. The loss through a UVSJ is less than that of a reversed splitter so you will likely not need to amplify the VHF side.

Because you are right on the edge with several UHF channels, I'm suggesting this arrangement as the means to maximize every bit of noise margin possible.

sdubb

25-May-2011, 8:24 PM

I totally forgot about the UVSJ until your most recent post. I google what they were before you posted that link. I was thinking that is exactly what I need and its not to expensive.

I understand your diagram. Luckily I can do what you have pictured since there are outlets on the roof. (not sure if they even work though) :confused:

I still am planning on using a short piece coming right off the XG91 to see what this "high gain" is doing for me. I am glad that it picked up 15 but thought I would have been able to get 51 with this new antenna.

Side note... how does the UVSJ work as far as knowing what to let thru on both sides?

Also kind of sad that I had to buy this nice new antenna for one channel :( (15)

The XG-91 did pick up channel 10 :D which is a VHF ;)

GroundUrMast

25-May-2011, 8:41 PM

The UVSJ is a filter made of some combination of inductors and capacitors. The UHF port does not pass frequencies below channel 14 (470 MHz). Most UVSJ designs allow DC to just over 216 MHz (the upper end of channel 13) through the VHF port.

The losses are relatively low, about 0.5 to 1.0 dB for signals in the pass-bands. Frequencies outside the pass-bands are attenuated 20 or more dB.

As far as preamps go, the power is fed up the coax from inside the building. The amplifier should be located within a short coax jumper length of the antenna. It would be quite unusual to locate the power supply on the roof or outdoors, most are not rated for such installation.

No static at all

25-May-2011, 9:22 PM

Also kind of sad that I had to buy this nice new antenna for one channel :( (15)How much elevation tweaking did you do? That has been the key for getting difficult channels in many situations for me. Just a few inches can make or break reception on UHF. I suggest raising/lowering the antenna in 3-4 inch increments. Re-test all channels each time as the tweaking may require a compromise to recieve everything.

How far is the antenna from the roof or any other metal objects?

sdubb

25-May-2011, 9:38 PM

As far as preamps go, the power is fed up the coax from inside the building. The amplifier should be located within a short coax jumper length of the antenna. It would be quite unusual to locate the power supply on the roof or outdoors, most are not rated for such installation.

This might be the killer... There is only one line that enters the house, If I have to add a seperate line its going to be a very interesting run to get the cable where it need to go (same place as the other one) they have all been run thru the house.

sdubb

25-May-2011, 9:45 PM

How much elevation tweaking did you do? That has been the key for getting difficult channels in many situations for me. Just a few inches can make or break reception on UHF. I suggest raising/lowering the antenna in 3-4 inch increments. Re-test all channels each time as the tweaking may require a compromise to recieve everything.

How far is the antenna from the roof or any other metal objects?

I did a little bit of tweaking as far as height is concerned. I started with the antenna at the back of the house on a pole about 12-13 feet. Then I decided that I needed to move it to the front of the house. Nothing really changed. I decided to mount a J-mount on top of a false wall on the roof which gave me about 8 more feet. So now my VHF/UHF antenna sits at about 21' in the air.

Like I stated the antenna is on the roof at about 8' above the actual roof. I dont see any metal objects any where close by, not even any power lines.

I can provide pics if you guys think that will help.

sdubb

2-Aug-2011, 4:57 AM

BIG THANKS to Groundurmast! and other for the help. I finally bought the 10G221 and am finally able to get channel 51.1 51.2 51.3 :D:D:D:D:D:D:D:D:D
The signal is in the mid 60's (Sharp Aquos meter) but its not breaking in and out. I am sure with some more tweaking I will be able to get it a little higher. I still need to do some fine tuning but I just had to throw it together after it came in the mail today.

Now I need to read up on "grounding my mast" no seriously I do. ;)

GroundUrMast

2-Aug-2011, 6:16 AM

Thanks for the update, glad that you're seeing KPPX!

sdubb

13-Sep-2011, 2:42 AM

This is getting ridiculous!!! I had everything dialed in 2 weeks ago, All my channels were working and even recorded a show on 15.1 fast forward to now 15.1 is basically gone I have no signal strength and when I do get it, it pops in and out and is only stable for about 5 seconds. Nothing has changed on my roof its all bolted down and locked down.

Anybody have any other ideas before I pitch all this equipment off my roof

GroundUrMast

13-Sep-2011, 3:55 AM