Is my antenna too big? (still within return date...I think)

#1
Hey guys,

I'm a newbie here. Switching over from dish to over the air, and I don't know a whole lot about it.......yet. I started off using the antennaweb site to select an antenna. I could have probably used a 7084p and an 8700 pre-amp, but I thought "why not go bigger" and got the 8200U with the 8700 pre-amp. I live on the east edge of Michigan's thumb, and I'm really close to Canada. Detroit is about 45 miles to the SSW of me. I'd like to get Detroit's stations as well as Canada's (for good hockey viewing!!). So I will be buying a rotor as well, and all of this will be on a tower with the antenna at 30ft above ground. I will also be using a distribution booster amp (about 12 coax locations in the house).

None of this is hooked up yet.....the antenna and pre-amp are all I have right now......waiting to find a good rotor, and I'm ordering the tower soon.

Now, after bought the 8200U and 8700 pre amp, I found the TVfool link on here. Tried that, and I didn't realize some stations were that close to me. From what I've read, I don't want to pre-amp anything closer than 35 miles, but I don't know that for sure.

So with that, is the 8200U and 8700 too much? I'm still within the timeline that I can return it if its too big, and go with the 7084p (or something else you guys think is good) so I'm hoping you can help me before the date passes by.

Basically there are two reasons I'm wondering if the 8200U is right for me:

1. Worried about overload. Will I be fine?

2. If I'm reading the TVfool correctly, is it worth going 8200U (or even 7084p) for the channels 2 through 6 that I will pick up? I DO want to pick up FM.

HELP!!! LOL

Here's what the TVfool told me: (click here)

Or look here:





 
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Trip

Moderator, , , Webmaster of: Rabbit Ears
Staff member
#2
I doubt there's such a thing as "too much antenna."

The Canadian stations on your list are currently only in analog, and many of them may not survive Canada's digital transition in August of 2011. The ones that are closest to you are at low power levels, while the ones further away are probably not strong enough to overload you.

What I would do in your case is try the antenna without the pre-amplifier and add it only if you find you need it for reliable reception. I doubt the antenna on its own would cause you overload problems, but the pre-amp could certainly do it.

I'll leave the particulars to the antenna experts, who should be along soon enough. :)

- Trip
 

Eureka

DTVUSA Member
#3
Unless you just have to have CIII-TV ch 6, you really don't need an all-channel antenna. A smaller, VHF-HI + UHF model would work just as well. And the shorter elements are much less likely to suffer from metal fatigue or drooping/bending from large birds or ice storms. The Winegard HD769x series is a good example.

Definitely try an antenna w/o an amp, first.
 

Don_M

DTVUSA Member
#4
Trip's advice is pretty much on target. "Too much antenna" can happen, but not at that location. An 8200 should keep you happy for years.

My own hunch is that the pre-amp will be necessary given the tower's height. The downlead run is probably at least 60 feet long, and maybe much more. The longer the cable, the more significant the signal loss, particularly on higher UHF channels. Given the distance and the number of drops involved here, a distribution amp by itself won't cut it -- the signals need a boost right at the antenna.

The AP-8700 is probably the best pre-amp for this application.

When designing the distribution system, I'd suggest installing the distribution amp downstream of the first splitter. Staggering the amplifiers should preclude both amplifier overload and tuner overload anywhere in the system. The AP-8700 has sufficient gain to overcome losses from the long cable downlead plus a four-way splitter. Three of this splitter's outputs may be used for initial TV/FM drops, leaving one output for the rest of the system.

From that point, you have two choices for system design:

• Connecting this output to a good, low-noise distribution amp such as the Winegard HDA-200, which has enough gain for the next five or six drops, with a second distribution amp, a lower-gain HDA-100, powering the remaining drops.

• Connecting the output to a single distribution amp such as a Channel Master 3418, which has eight built-in connectors as well as a very low noise figure. You would need to split one of the eight outputs for use at two drops, which can be practical as long as these two cables are the shortest ones in the system.
 
#5
Hey guys,

I can't thank you guys enough. I've talked to a few other places and only heard the basic "generally" type answers. This is some really really good info on here. I've already bought the antenna and pre-amp while I was at the store which is 2 hours away. They are the best place around to get towers from, and that is why I stopped in. They are waiting for me to call back to order the tower (I couldn't take it with me the day I was there.....had the minivan). And it just so happens that we are ordering two towers from them for work, so I can have them put it on one delivery. I was waiting to see if the 8200U was too big before I ordered, because I would have had them ship a different antenna with the towers. Since the 8200 seems to be a good choice, I'm going to call them tonight and get the towers on order. I know the 8200 is HUGE, and the 7698 would probably be fine too, but besides the possibility of birds/ice, is there any other downfall of the 8200? The tower will have the built in rotor "bearing" tube to protect the rotor from twisting.

Anyways, back on track........I was planning on the 8700 on the tower. From the antenna to the first splitter location in the house should be about 45 feet max. From there, it gets confusing. I know I'll need a distribution amp, if not two or three. It's hard to describe how the house is laid out.

Would it be OK if I drew up a quick schematic of my house to show you guys where the coax connections are in the walls? I can take measurements tonight to make a nice "map" of all of it.

Thanks guys!! You definitely know your stuff!!
 

Don_M

DTVUSA Member
#6
You can if you like... but beyond a certain point, nothing beats being able to stand there and look at it in person. Most people we advise have one, two or three wall plates, not 12. Luckily, it's not difficult to put together a good distribution system by following these rules of thumb:

• With both pre-amps and distribution amps, the ideal system roughly balances amplifier gains with system losses. As you may know, both are measured in decibels -- a logarithmic scale, but one allowing for the use of simple addition and subtraction to determine how much amplifier gain will be needed. You want system losses to come within +/- 2 dB of the gain of the amp that powers signals in that part of the system.

• Between each amp, figure that each splitter output represents a 3.5-dB signal loss.

• Between amps and splitters, and also between every splitter port and wall plate, assume that each 20 feet of RG-6 cable equals 1 dB of signal loss, 40 feet of cable is 2 dB, etc.

That's basically how the AP-8700's gain is just about perfect for the downlead and first splitter: 45 feet of cable = 2 db, plus four splitter outputs times 3.5 dB = 14 dB. The total is 16 dB, which is just shy of the 8700's UHF gain. (VHF cable losses are significantly lower, so the pre-amp's lower VHF gain is nothing to worry about.) This is ideal as long as none of the cables attached to the splitter would be longer than roughly 50 feet. The same principles hold true for splitters and cables located beyond each additional distribution amp as well.

More considerations:

• It's far too easy to underestimate the length of cable needed for a given run. Here's a personal example: I have antennas in the attic, about 25 feet away (in a straight line) from our only HDTV in the basement. By the time I'd snaked the downlead through closets and walls, around corners and duct work and under a staircase, the cable was 55 feet long. Within-the-inch accuracy isn't necessary, but you will need fairly good numbers to figure cable losses throughout the system.

• Get a 500- or 1000-foot box or reel of RG-6 coax. You're going to need it to do custom cable lengths in a system that extensive.

• Before you start the actual work, practice compressing F-connectors onto cable ends until you're completely comfortable doing it. Poor cable connectors are the Achilles heel of most DIY signal distribution systems. Shorts or poor electrical connections at a crucial point (such as at either end of the downlead cable) will kill off signals in large portions of (or everywhere in) the system. Get each F-connector done right the first time, and the system you build is likely to remain reliable as long as the house is still standing.

Are you dealing with Solid Signal? IIRC, they're in Novi, which looks to be just about two hours from your town. It's a good company, and their net-of-shipping prices are the best available anywhere.
 
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Piggie

Super Moderator
#7
Anyways, back on track........I was planning on the 8700 on the tower. From the antenna to the first splitter location in the house should be about 45 feet max. From there, it gets confusing. I know I'll need a distribution amp, if not two or three. It's hard to describe how the house is laid out.

Would it be OK if I drew up a quick schematic of my house to show you guys where the coax connections are in the walls? I can take measurements tonight to make a nice "map" of all of it.

Thanks guys!! You definitely know your stuff!!
Yes, the coax map would be a great idea. It would then be possible to actually engineer your distribution system and not just guess.
Also include an FMFool.com plot for your house.

-----------

I have one suggestion not covered here, more of a change.

I would use a Winegard HDP-269 amp on the mast. Three reasons.

1) You want FM and with the 8700 you are paying for an FM trap you will be turning off.

2) You are paying for more gain than you need on the mast with a 8700

3) The HDP-269 has more dynamic range than the 8700 for overload.

========

To highlight what led me to this.

First in order to split 12 ways in the house you would need so much gain on the mast, you would then have too much gain at the mast leading to overload. There is a some what of an inverse correlation between gain and dynamic range (overload potential). The more gain an amp has the less dynamic range, or the easier it is to overload.

Now we haven't seen an FMFool plot for your house but lets guess there is significant FM signals in your area.

A HDP-269 will put out 12 db of gain. 60 ft of RG6 cable inside is at worst case 3 db being conservative. If the distribution amp is very close to some of the receivers, then after a 4 way splitter you would have you would still have a little better than a db left, that could drive 10 ft of coax. Or if it goes in a distribution amp it would hit the second amp at near unity gain, which is critical in figuring cascaded amp distribution systems.

Other choices where it goes inside are two 2-way splitters. If say one TV was 20 ft away, it gets the first split which then has 3 db more gain, and a receiver very close and the indoor distribution amp gets the double split.

If there is more than 60 ft of cable or any set is more than 10 ft from an initial 4-way splitter the HDP-269 would run out of power.

The complete schematic would be the best just spouting possibilities.

That all said the 8700 should not overload per the TVFool plot. It just might be more amp than needed, again depending on the exact schematic.
 
#8
OK heres it my two cents for UHf 91-xg from antenna direct, VHf Wineguard YA1713 then place the Channel master titan 7777 premap to combine the two this with the channel master programmable rotator should give you the best performance bar none, of course this is my opinion from many installs of many antennas
 

Don_M

DTVUSA Member
#9
Now we haven't seen an FMFool plot for your house but lets guess there is significant FM signals in your area.
Not really. I did an FMFool report @ 30 feet for the ZIP code and didn't bring it up because:

• CBEG is the only strong FM station in the general direction of any desired TV signals. It might cause harmonics issues with a channel 8 signal, but there aren't any channel 8 stations to worry about. Besides, CBEG's 1,800-watt ERP isn't exactly screaming hot.

• None of the other five strong FM stations is within 65 degrees of desired TV signals; most are much further away than that.
 

Piggie

Super Moderator
#10
Not really. I did an FMFool report @ 30 feet for the ZIP code and didn't bring it up because:

• CBEG is the only strong FM station in the general direction of any desired TV signals. It might cause harmonics issues with a channel 8 signal, but there aren't any channel 8 stations to worry about. Besides, CBEG's 1,800-watt ERP isn't exactly screaming hot.

• None of the other five strong FM stations is within 65 degrees of desired TV signals; most are much further away than that.
great!

A btw that probably turn on EV more than I but the HDP-269 makes a great FM broadcast distrubution amp if you have several receiver drops and long runs. Mine is a total of 100 ft from the antenna through 2 two way splitters. FM is only about 2 db loss per 100 ft, but I use RG59 for FM, using an amp, then 7 db or so in splitters, I about neutralize the small gain of a the amp with a modest distribution system.
 
#11
My head hurts!!! LOL!! That is a lot of info to take in. VERY much appreciated though. I just got done doing my measurements and sketching it out on paper. I'm going to draw it up in Paint and post it on here. Hopefully won't take that long.

Thanks for EVERYTHING so far guys!!!:hail:
 

Piggie

Super Moderator
#12
My head hurts!!! LOL!! That is a lot of info to take in. VERY much appreciated though. I just got done doing my measurements and sketching it out on paper. I'm going to draw it up in Paint and post it on here. Hopefully won't take that long.

Thanks for EVERYTHING so far guys!!!:hail:
Take you time. But now you know how we felt (head hurting) for about a month before and weeks after the transition. There were 10 to 20 people a day asking what antenna to buy. It was a marathon.
 
#13
OK, here goes....

The blue 35ft and 6ft are the length from tower to basement wall, and from basement wall to where all of my lines were run when the house was built. The person who did the wiring ran all of the wires to one location (A) as a distribution point. All of the measurements on the drawing are from point A to that wall's coax jack. Basically, each bedroom has one cable run from location A, and it splits to both walls of that bedroom. The living room has its own run, as does the computer closet and garage.

The two basement runs and the dining room run are not there yet (will be added soon).

I also added in points B and C in case they were a good location for splitters/dist amps. The distance from point A to B is 28ft, and from B to C is 10ft.

All measurements included going up the wall to get to the wall jack.

I have no idea where to begin putting splitters and distribution amps, and it might be tricky for you guys to tell me where, so I tried to use multiple colors. And if you can't tell, I was running out of colors to use on Paint. I left it as a bmp file, so it might take a bit to load. I also saved it as a jpg, but it wasn't as easy to tell some of the colors apart. If file size is an issue, I'll reload it as the jpg version.

Thanks!!

 
#14
And to add one more question.......lets say in Bedroom A, the coax is hooked to the TV. Then we decide to also hook up an FM stereo in that room. Can we just put a two-way splitter before the TV and run one to the TV, and one to the FM radio? This will probably happen in both bedrooms, and will for sure happen in the garage.
 
#15
Are you dealing with Solid Signal? IIRC, they're in Novi, which looks to be just about two hours from your town. It's a good company, and their net-of-shipping prices are the best available anywhere.
I looked at Solid Signal online, but you can't go inside the store. I'm more of a "I wanna see what we're talking about" kind of person. I'm dealing with Bursma in Bay City. Marty is a really good guy to deal with, and their prices are great. The price on the 8200U was actually $5 less than SS. I think it was about the same price on the 7084. The 8700 pre-amp was also $5 less than SS.
 

Don_M

DTVUSA Member
#16
Lets say in Bedroom A, the coax is hooked to the TV. Then we decide to also hook up an FM stereo in that room. Can we just put a two-way splitter before the TV and run one to the TV, and one to the FM radio?
Absolutely, as long as the TV signals at each location are strong enough to counteract splitter losses. If loss is a potential issue, you could use Winegard CA-8800 TV/FM band separators instead of splitters. While they're more expensive -- ~$15 instead of maybe $2 -- the insertion loss is an almost-invisible 0.4 dB per port versus 3.5 dB per port. I use one, and they're a terrific way to sidestep signal loss.

NeedfreeTV said:
I'm dealing with Bursma in Bay City. Marty is a really good guy to deal with, and their prices are great.
Never done business there, but he does have a really great reputation, too.
 
#17
Absolutely, as long as the TV signals at each location are strong enough to counteract splitter losses. If loss is a potential issue, you could use Winegard CA-8800 TV/FM band separators instead of splitters. While they're more expensive -- ~$15 instead of maybe $2 -- the insertion loss is an almost-invisible 0.4 dB per port versus 3.5 dB per port. I use one, and they're a terrific way to sidestep signal loss.
Great idea. I didn't know those existed. Well worth the extra few bucks I'd say.
 

Piggie

Super Moderator
#18
OK, here goes....

The blue 35ft and 6ft are the length from tower to basement wall, and from basement wall to where all of my lines were run when the house was built. The person who did the wiring ran all of the wires to one location (A) as a distribution point. All of the measurements on the drawing are from point A to that wall's coax jack. Basically, each bedroom has one cable run from location A, and it splits to both walls of that bedroom. The living room has its own run, as does the computer closet and garage.
These are as much questions as answers.

1) So it's about a 41 ft run from the top of the tower to point A ???

If this is true, then the HDP-269 would be good up top so there is as little extra signal at Point A as possible. Even then, with 12 db out of the HDP-269, the coax would be 3 db tops. That would leave 9 db, way too much to hit the second amp (distribution amp). Like Don said earlier to run a distribution amp, the antenna would need to hit a splitter first.

If you hit a 4 way first before the distro amp, you would have a total loss of about 10 db. Or a gain of 2 db from the HDP-269. 2db overhead would not be too much to hit the distro amp. The other 3 outputs of the 4 way passive could feed the garage basement and the other short cable (you have three runs from point A that are 20 ft or so. With 2 db left over you could drive 20 ft of coax and TV/FM splitter, cutting to the edge with a db left left over.

The other 5 runs would have to come from a powered distro amp in the order of no more than 10 db of gain to feed the longer runs.

2) But if you have the larger amp with 19 db of output, and you are splitting it with an 8 way at point A, then using an FM/TV splitter in each room, you might not need a distribution amp.

Lets look at the longest run, Master Bedroom. Total coax is 125 ft, then look at the worst case channel which is 51 at 600 MHz. RG6 has about 5 db of loss per 100 ft, so 125 ft would be 6.25 db loss (perfect world, but add connectors and lets say it's 7 db)

Ok, 7 db in the coax. Then an 8 way splitter (this assumes there is actually only one coax to each bedroom from point A), adds about 10 db of loss. Then in the bedroom you have the FM/TV splitter and jumpers, which total about a db.

So to this point we have 18 db of loss from the output of the mast mounted preamp to the TV in Master Bedroom.

The 8700 has 19 db of gain. That leave 1 db left over to play with, or a bad connection you know know is loosing more, etc etc.

Remember, this is the worst case on an imaginary channel 51, which has the greatest loss. Channel 16 would have about a db less loss and high band about 3 db less loss.

You could probably go with a slightly larger amp not using a distribution amp, but the 8700 should be fine.


==========

Conclusion, and please someone that follows my db gains and losses double check my math, but it looks like the 8700 at the antenna will power the entire house with about 3 db left over on ch 51 in the master bedroom.

If that is true, you are much better off with just one amp. Cascading amps sometimes just works, sometimes makes a mess.

Don can you double check my gains and losses to see if I figured it right not to run a distro but a passive 8 way at point A?
 
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#19
Thanks P,

In the past, it was my understanding that:

1. You have to take all of the collective lengths and add them up for a total loss through the system.

2. Every time you split the signal, then entire system will notice the loss.

So are either of those correct? I'm trying to figure out if you are saying the longest length would be 125ft, then it would lose 18db from the pre-amp's 19 gain. But wouldn't the other lengths also contribute to more loss?

But back to your post.....

Option #1. I like that option. Going with the smaller HDP-269 pre-amp on the tower, and running into a 4-way splitter first, using 3 lines to go to the basement (46ft), the garage (22ft), and the kitchen (16ft), and the fourth into a 4-way distribution amp CM 3414:

Output 1 feeds the computer (28ft), and splits to the living room.(26ft past computer)
Output 2 feeds Bedroom A (48ft), and splits to the second wall in Bedroom A (12ft more)
Output 3 feeds Bedroom B (60ft), and splits to the second wall in Bedroom B (12 ft more)
Output 4 feeds both Master Bedroom walls (72ft from Output 4 to a second splitter which would leave 12 ft to wall #1 and 12 ft to wall #2)

***As a note, the 20ft basement wall run is not a necessity. I can forget it if I want to****

Does that arrangement make sense?

Or could I run from the HDP-269 into a two way splitter. Run one splitter lead to the short 16ft kitchen wall. Then run the other lead into an 8-way CM 3418:

Use the outputs 2,3, and 4 as listed above.
Output 1 feeds the computer (28ft)
Output 5 feeds the living room (54ft)
Output 6 feeds the garage (22ft)
Output 7 feeds basement wall (46ft)
Output 8 feeds basement wall (20ft)

Is that a better plan for Option #1?

Option #2 If you're thinking that the 8700 MIGHT do it alone, what about if I returned the 8700 and went with the next step up? Like the 8275? Would that help to make sure I don't need the distribution amp?

Thanks!!
 
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Don_M

DTVUSA Member
#20
Don can you double check my gains and losses to see if I figured it right not to run a distro but a passive 8 way at point A?
As I alluded to earlier, big distribution systems are rather outside my expertise. I was proceeding under the assumption that...
1. You have to take all of the collective lengths and add them up for a total loss through the system.

2. Every time you split the signal, then entire system will notice the loss.
... but then, I never earned a ham ticket and never held anything more advanced than the old 3rd Class Radiotelephone license (which, as you know, wasn't really all that advanced). Seems my numbers for each splitter were off, but my impression is similar to "Need's" in that each additional splitter output tap means that much more system loss.

Now you can call me "confooozed." Guess you're going to have to take us to school, Piggie!

:mad:)
 

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