Requesting the Pro’s Opinion – Complete Antenna System

[Burr]

Please see reports:
http://www.tvfool.com/?option=com_wr...d243af446ec2a2
http://www.tvfool.com/?option=com_wr...d243bc517fbc71

Hello,
This is a great site and excellent resources. You’ll be happy to know I’ve made no mistakes yet…… mainly because I’ve yet to purchase the antenna, rotor, mount, hardware, etc.

If seen from overhead my home appears enclosed by a forest, the exception being an open area to the South roughly between 157° & 182° and approximately 200 feet in length from the proposed antenna location, otherwise the forest is within 100 feet. Unwilling to mount an antenna on the roof, I’m considering a pole mount design with rotor (if necessary) positioned at the extreme NW corner of my home. In this location and at a preferred maximum height of 20 feet it will be less visible from the front of my home.

From 182° to 75° the antenna should have no direct interference from the home’s hip style roof structure. However, I’m guessing the signal of desirable channels located at or between 165° and 173° may be affected by the roof structure, not due its direct obstruction but thru a signal reflection as it interacts with the roof and its own signal. The roof’s pitch is 22.5 degrees and this in relationship to the signal’s source probably creates some oblique angle of reflection that makes my head hurt to think about. Proof positive that a “little knowledge” can be a dangerous thing.

Additional information:
Cabling length:
From the antenna to split point is less than 75 feet with no cabling as yet installed. I could reposition some existing coax of sufficient length for impute from the antenna to split point, it’s labeled “Prime P6400BX-PB-500, Dual RG6 CCS, 60% A1, Braid E23357 75C (UL) CMX/CATUX/CL2X.” Is reuse of this cabling advisable or advantageous to your recommended system design?
Cabling length:
From split point to four sets (2 – HDTV’s & 2 – relics) using existing RG-6 cabling of less than 50’ average lengths.
Historical:
We’ve only known satellite & cable service. Therefore, your recommendation(s) of accessories necessary to receive and view a picture on our two older (coax compatible) TV’s is requested.

My objective is to acquire every VHF/UHF channel reasonable and I would greatly appreciate your considered opinions/recommendations/options for a complete DIY system (antenna, mounts, rotor, etc.) for the conditions given.

Thanks in advance,
Burr

[StephanieS]

Greetings Burr,

Your goals while ambitious, might be tempered by the trees. Trees often wreak havoc on incoming signals shredding them and deflecting them away from your antenna. The result can be even signals of good strength are unreliable. You are fortunate that magnetic heading 171 - 173 is clear. If I were installing at your location the Grand Rapids market gives a nice chance for a complete set of the major affiliates with a outside shot at WGVK PBS.

Generally I favor configurations that don't include rotors. Rotors while occasionally required are just another component to fail. I much prefer being able to lock down my antenna at one heading.

Your map has a multitude of directions and bands to consider. You have low-vhf, high-vhf and UHF to consider. Also important points is what is the best direction to aim (best bang or buck or most stations accessible) and what works best with your treeline.

I would do a two antenna set up. The first would be an Antennas Direct DB8e for UHF (real channels 14 and up). This would focus on FOX WXMI and WOTV ABC.

The second antenna would be an all band VHF/UHF combo. You'll notice WGVK broadcasts on low-VHF channel 5, so an antenna that works with low-band VHF is required. The UHF capability, however for the second antenna you would not be using. This antenna would be an Antennacraft HD1850. This antenna would be responsible for WOOD NBC and WWMT CBS along and a trying for WGVK.

Orientate DB8e to magnetic 172. Orientate HD1850 to magnetic 172. When mounting the antennas on the mast, install DB8e at the very top with the HD1850 about 4' below.

I would expect in this configuration to see FOX, CBS, ABC, NBC, WLLA along with a shot at PBS WGVK. You may see additional signals off the back or sides. Grand Rapids though is the focus of where I'm going with this set up.

A mast mounted combiner, the Antennas Direct EU385CF is a quality unit. DB8e coax to UHF combiner input, HD1850 coax to VHF combiner input then run your single lead into your home. Since you are doing 4 splits a Channel Master 3414 distribution amp might be a good option to install instead of a preamp.

Your situation isn't ideal with so many pathways to consider. Your opening to the south of your property gives the best window at reception that'll be reliable. It also happens to luckily fall in the direction of Grand Rapids' broadcasts.

As for your older TVs which you need a digital capable external tuner, Amazon's ratings of the Mediasonic HW180STB are at 4 stars out of 5.

Cheers.

[timgr]

Curious - why the HD1850 instead of the Y10713?

Never mind - answered my own question. It's about VHF low band.

[Burr]

Imathankinyou! Although it will take some time to digest all the product information recommended it's a great start. At this stage of my learning process I still have interest exploring the benefit/drawback of this design versus a directional antenna

Based upon these potential signals availablility, is a comparable quantity and quality of signal achievable using a directional antenna design? I would include the use of a high quality rotor (nod to your apprehension) in the system.

Here's my thinking, for 6-months of the year these tyrannical wooden giants lose some of their bluster (leaves) and from what I've learned so far, that's a good thing for antennas! If during the winter a directional antenna gives me access to a greater number of channels due its greater gain or aiming precision it may keep my cabin fever in check.

Note: I was surprised by recent reviews of the HW180STB. Several indicated failures after 6-months. Again, thank you and all who've spent time reviewing this thread.

Burr

[Tower Guy]

I would ignore PBS on low band channel 5. The signal is weak plus you have another PBS that is easier to pick up.

[tomfoolery]

Originally Posted by Tower Guy

I would ignore PBS on low band channel 5. The signal is weak plus you have another PBS that is easier to pick up.

RabbitEars also identifies WGVK real 5 as "WGVU" in the Nickname column, along with it's subchannels, so it would seem to be basically the same station as WGVU on real 11, but on low-VHF from another tower. Suggesting there's nothing to be gained with an antenna with low-VHF in this instance.

http://www.rabbitears.info/market.ph...n=wgvu#station

[Burr]

Thanks, removing the low-VHF capability is appropriate and regarding th system recommendations based upon a directional antenna; I suspect this really comes down to a gut call but I'd still like your thoughts.

Rookie mistake, better put as; "removing the low-VHF capability seems appropriate"

[StephanieS]

My rationale for WGVK is twofold:

1. The treeline is more favorable in the direction of WGVK as opposed to the other, stronger PBS.

2. Since you are already pointing at magnetic 172 and require high-VHF capability for CBS and NBC adding low-VHF capability to add the chance at WGVK would be wiser than being at the mercy of foliage and foliage induced unreliability of WGVU combined with pointing off to the side of it.

Again, it all goes down to gut calls. Just sharing mine.

[Tower Guy]

Originally Posted by StephanieS

adding low-VHF capability to add the chance at WGVK would be wiser than being at the mercy of foliage and foliage induced unreliability of WGVU combined with pointing off to the side of it.

The low band interference may be worse than the trees on UHF. I have often found poor reception of low band below 15 db NM. The FCC planning factors added 4 db for low band noise. It's often more than that. TVfool's calculation ignores the extra noise.

[Burr]

Did I just have an epiphany? Let’s assume I’m willing to take low-VHF capability off the table, let’s further assume the miss’s and I like different programming, it’s a stretch I know. Utilizing two antennas with the 1st at the uppermost mounting (20’) is a direct able antenna (with rotor) and the 2nd antenna is in a fixed position mounting (16’) aimed to magnetic 172°. This combination seems to provide the sweet spot coverage at 172° and also satisfy the gambler in me hoping for other channels.

I’m guessing here but to reduce the systems complexity, each antenna could be dedicated to an area. The 1st area (upper floor) is supplied by the fixed position antenna aimed at 172° and serving two HDTV’s plus one relic. The 2nd area (lower floor) is supplied by the direct able antenna with rotor serving one relic TV. Assuming the control and signal of the rotor equipped antenna can reasonably be accessed by only one area, it would serve 2nd area.

Is this a workable concept and does it change the antenna(s) or accessories? Can I expect the direct able antenna’s signal strength when rotated to 172° will mirror that of the fixed position antenna? Does this bring into play the dual RG6 cabling mentioned earlier? Thanks in advance.

[timgr]

Just for your consideration ...

You can have as many fixed antennas as you want, if you have the budget, the room on the roof and a tuner for each. You don't need a rotator if your fixed antennas cover the channels you want. Connect the tuners to a HTPC (home theatre PC) working as a DVR and send saved or live programming from any of the covered channels to any TV in the house. The Silicon Dust tuners are very popular - http://www.silicondust.com/

[Burr]

The more I learn, the more I realize how little I know about designing a complete system. My budget isn't unlimited but probably justifiable when terminating cable cost is factored in.

I'm interested "timger's fixed antenna(s), tuners and HTPC suggestion. A couple questions if you would.

1) I've read about issues that occur when consolidating multiple antennas, are these issues negated by the tuners or the HTPC?
2) In this scenario, I like "StephanieS" configuration (post #2). Is it appropriate as a base system to now or later build into a tuner/HTPC system?
3) Could you supply a link to an appropriate diagram (block diagram) of a typical antenna/tuner/HTPC system?

Just for your consideration ...

You can have as many fixed antennas as you want, if you have the budget, the room on the roof and a tuner for each. You don't need a rotator if your fixed antennas cover the channels you want. Connect the tuners to a HTPC (home theatre PC) working as a DVR and send saved or live programming from any of the covered channels to any TV in the house. The Silicon Dust tuners are very popular - http://www.silicondust.com/

[timgr]

Originally Posted by Burr

...
1) I've read about issues that occur when consolidating multiple antennas, are these issues negated by the tuners or the HTPC?
...

By combining the signal from multiple antennas in the analog RF domain, you are creating an antenna array. I believe there is plenty of voodoo that goes into making antenna arrays. I know a little about RF arrays (from MRI), and I understand a tiny bit about phased arrays. But designing an antenna array for a specific purpose requires a lot of knowledge ... I could probably do it after a couple of years of study, but I'm not going back to school.

However, combining antennas using two tuners just requires that the antennas be far enough apart on the roof that they are not electrically coupled by their proximity. Then each tuner decodes only the signal from a single antenna, and there is no mixing in the analog domain. The choice of which program you want is done in the digital domain (on the HTPC).

[tomfoolery]

Originally Posted by timgr

By combining the signal from multiple antennas in the analog RF domain, you are creating an antenna array. I believe there is plenty of voodoo that goes into making antenna arrays. I know a little about RF arrays (from MRI), and I understand a tiny bit about phased arrays. But designing an antenna array for a specific purpose requires a lot of knowledge ... I could probably do it after a couple of years of study, but I'm not going back to school.

However, combining antennas using two tuners just requires that the antennas be far enough apart on the roof that they are not electrically coupled by their proximity. Then each tuner decodes only the signal from a single antenna, and there is no mixing in the analog domain. The choice of which program you want is done in the digital domain (on the HTPC).

My neighbor has two or three separate antennas, all fed into separate tuner cards (or maybe they're SiliconDust HDHomeRun units) in his HTPC system, and all available on a single on-screen menu. One of these days I'll play around with making my own from the several computers I've got laying around, but in the mean time, I'm interested to hear what others have done, especially to combine multiple tuners.

[Burr]

I’m comfortable with “StephanieS” recommendations (see post #2, this thread) for a DB8e and HD1850 aimed to 172° and I’d like to incorporate “timgr”s suggestion (see post #11, this thread) to utilize tuners, HTPC (home theatre PC) working as a DVR system. Going further, I’d like to access VHF channel 13 (WZZM) which lies at 310 degrees. Your thoughts on the following are appreciated more than you know:
1. Would adding a second HD1850 (for channel 13) be acceptable if mast mounted with the 1st HD1850 and DB8e? You may assume the following changes to original design:
a. Increasing the overall mast height to 25’.
b. For maximum separation of the VHF antennas I’d mount the 1st at 25’ aimed at 172° and the 2nd at 17’ aimed at 310° with the DB8e aimed at 172° and mounted at 21’ and between the two HD1850’s.
2. Given the use of a Tuner(s), HTPC, DVR system can you confirm or guide me with the following:
a. The need for a VHF/UHF antenna combiner is eliminated.
b. How’s the three antenna’s signal best conveyed back to the tuners? I’d expect to locate the tuners with the DVR a maximum 75’ from antenna source and at the split area for installed RG6 cabling to each room/set.
c. Is the ChannelMaster 3414 distribution amp still needed?
d. Digital capable external tuners for each (2) of my older TV’s is still required.
e. Does a mast mounted preamp come back into play?
3. So I have a clear understanding of all the components required and their routing can you provide a link to a block diagram or walk me thru the system here.
4. Lastly, since the DB8e’s has the ability to focus its two antenna segments separately, I’m sure to try aiming one bay/element at 172° and the second bay/element at a few UHF channels near 290°. Any guess as to the DB8e’s single bay performance potential under these conditions?

Best regards,
Burr

[tomfoolery]

Originally Posted by Burr

4. Lastly, since the DB8e’s has the ability to focus its two antenna segments separately, I’m sure to try aiming one bay/element at 172° and the second bay/element at a few UHF channels near 290°. Any guess as to the DB8e’s single bay performance potential under these conditions?

According to the technical pages available on Antennas Direct's web site, the gain at +/-60 degrees off straight ahead drops to about 8-12 dB, with the lower gain at the lowest channel (14) and climbing at the highest (51). Gain figures are about 15-17.5 dB when both are aimed to the same direction. You can download that document from their site.

[timgr]

Originally Posted by Burr

1. Would adding a second HD1850 (for channel 13) be acceptable if mast mounted with the 1st HD1850 and DB8e? ...

Hi - I think you may have missed the point of the UHF-VHF combiner. You can mix one VHF and one UHF antenna in the preamp, because the frequency range of VHF is different from UHF, and vice-versa. They cannot interfere with with other because they operate on widely separated frequencies.

When you connect the HD1850 to the VHF port of the preamp, you are blocking any UHF signals from that cable. So you turn a VHF-UHF antenna into a VHF-only antenna, and there is no conflict.

If you try to combine two VHF antenna signals they may add happily, or the signal quality could go down due to cancellation or added noise. Can't predict - too many unknowns. You can try it if you want.

If the two VHF antennas were widely separated so they were not electrically coupled (more than a few feet), you could send each signal to a separate tuner and combine them that way. The tuner would turn each signal into a digital stream that would be stored or streamed by your HTPC.

For the block diagram, you could look at the Silicondust website. They have some video presentations (which my privacy blocker won't allow through - so I can't tell you specifically what to look at). But it should be easy to find a description of the type of system you want.