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-   -   Antenna Suggestion? (http://forum.tvfool.com/showthread.php?t=15587)

michaelt84 4-Jun-2015 6:24 PM

Antenna Suggestion?
 
We are reroofing our house and I’m looking to replace an old antenna that came with the house. In order to keep an OTA antenna, I’ve promised my better half that I will relocate it from the chimney on the front of the house to a less visible location on the side/back of the house, which shouldn’t affect the LOS. I’m also replacing all the coax with new RG6.

Here is a link to our report: TVFool Report

I really only need ABC, CBS, CW, FOX, NBC and PBS, which cover both VHF Hi-Band and UHF; all the transmitters I need are located about 30 miles away at 81° on Mt. Wilson in LA, so I’m looking at a highly directional antenna. According to my report, the strongest signal I need to receive is -71.5 dBm and the weakest is -98.0 dBm. I do have some significant terrain and trees between our house and Mt. Wilson. Last night I was able to pick up a very pixelated signal from a station (I0N/30.1) that is listed at -108.9 dBm at 83°.

For some unknown reason, I’m intermittently unable to receive one of the main networks, possibly KABC in the VHF Hi-Band, but can’t remember for sure … and of course everything is coming in perfectly when I check now. These outages seem to only occur in the 9th inning of baseball games or on the 18th green of major golf tournaments.

Here is my current OTA setup:
Existing antenna

Channel Master Model 7777 Preamp

Channel Master Model 0747 Power Supply

PCT-MA2-8P Distribution Amp
I assume that I’m looking for something like one of these:
Solid Signal Xtreme Signal Long Range HD VHF/UHF/FM Antenna(HD8200XL)

Winegard Heavy Duty Platinum VHF/UHF/FM HDTV Antenna(HD8200U)
I wouldn’t mind using the antenna for FM reception as well, if it doesn’t detract from HDTV reception.

Is there a specific antenna that you would recommend for my location? Also, should I reuse the existing Preamp & Distribution Amp or is there something better I should I install?

Thanks for any recommendations you can provide!

michaelt84 8-Jun-2015 6:05 PM

Still looking for a little assistance
 
Unfortunately, I haven't received any responses to my original post. Is there anything I missed in the post, e.g., too little/much info, or should I just be patient? I've enjoyed reading the other posts and responses in the forum, but this is my first post and I'm not sure if I'm going about this correctly.

Thanks for any help you guys can provide.

Billiam 8-Jun-2015 9:04 PM

Took a quick look at the report. Probably the Winegard 8200. May or may not need a rotor. Depends upon if you have multipath issues. I know I have several signals coming from 15 degrees at my home but they are pretty weak and I need to move the antenna a few inches to get one or two that won't come in a few inches in the other direction.

The Winegard 7698 would also work. But since you do have a Ch. 3 there and may want to watch it in the future if there is a programming change, might make sense to get the 8200.

ADTech 8-Jun-2015 10:09 PM

Your existing antenna is already a pretty good sized all-channel antenna. What's its total length?

rabbit73 9-Jun-2015 1:16 AM

Quote:

Originally Posted by michaelt84 (Post 51554)
Unfortunately, I haven't received any responses to my original post. Is there anything I missed in the post, e.g., too little/much info, or should I just be patient? I've enjoyed reading the other posts and responses in the forum, but this is my first post and I'm not sure if I'm going about this correctly.

You didn't do anything wrong and you have been more than patient. Most of us volunteer our time as available.

You don't need the 8200, and I doubt you will need the first 3 channels listed.

You already seem to have the right equipment for the job and your antenna looks a lot like the Winegard HD7698P, which would be suitable. So the reaction of people that look at your first post reminds us of a line from the King and I: "Is a puzzlement."

Your equipment might have deteriorated to the point that it no longer performs as designed. When you remount your antenna you will have a chance to do some substitution to find out if any part is defective.

The trees might be causing interference to your signals. Try to do everything you can to get a clear shot at the transmitters.
http://www.hdtvprimer.com/ANTENNAS/siting.html

michaelt84 9-Jun-2015 6:23 AM

Thanks for the responses ... I do understand and (very much appreciate!) that the gurus on here are volunteers. I was just getting a little nervous, since I saw that my request had received a lot of views but no responses and others were getting lots of responses. I wanted to make sure I was following all the proper protocols ... evidently some requests are just more interesting/puzzling than than mine!

My existing antenna is approximately 176" long and the total width of the longest elements is 107" ... possibly an earlier version of the Winegard HD8200U? Here are a couple more of pictures taken in the dark tonight:

Front end
Mounting clamps & coax connection
Side view

I'm not sure how old the antenna is (we bought the house - and the antenna - about 9 years ago) and I've read that antenna performance can start deteriorating after 10-15 years. Also, one of the longest two elements is broken/missing on the back end of the antenna, so I figured that now is as good a time as any to replace it.

Since I only have one bite at this apple, I just wanted to see if anyone had strong opinions on a better setup, e.g., you'll be better off with X preamp and Z distribution amp with the Winegard HD8200U. Size isn't really an issue and, with the most expensive OTA antenna i see being cheaper than a month of cable/satellite, neither is cost. The first channel I need is 7, and I don't expect to ever need 2 or 3.

I did a quick comparison of the performance data from the Winegard HD7698P and HD8200U and came up with the following:

HD7698P vs. HD8200U comparison Spreadsheet
HD7698 Spec Sheet
HD8200U Spec Sheet

In addition to being much narrower in size, the 7698 appears to have about 3dB of gain over the 8200 in the frequencies I need, i.e., channels 7 and 28-43 (a result of eliminating the low VHF band?). Is the 7698 the way to go for me?

Again ... thanks for the help!

rabbit73 9-Jun-2015 5:23 PM

2 Attachment(s)
You don't need the 8200 because you don't need real channels 2 and 3. KVTU is off the air, and KHIZ probably doesn't interest you.
http://www.rabbitears.info/market.ph...&callsign=knbc
http://en.wikipedia.org/wiki/KHIZ-LD

The 7698 looks good for you.

Quote:

I really only need ABC, CBS, CW, FOX, NBC and PBS, which cover both VHF Hi-Band and UHF; all the transmitters I need are located about 30 miles away at 81° on Mt. Wilson in LA, so I’m looking at a highly directional antenna. According to my report, the strongest signal I need to receive is -71.5 dBm and the weakest is -98.0 dBm.
ABC, KABC-TV, real channel 7, NM 19.3 dB
CBS, KCBS-DT, real channel 43, NM -7.1 dB
CW, KTLA-DT, real channel 31, NM 4.1 dB
FOX, KTTV, real channel 11, NM 16.3 dB
NBC, KNBC-DT, real channel 36, NM -0.2 dB
PBS, KOCE-DT, real channel 48, NM 0.6 dB
http://www.rabbitears.info/search.ph...pe=dBm&height=

CBS looks like the most difficult, with a NM of -7.1 dB. The NM of a signal must be at least 0 dB. The TVFOOL report assumes an antenna with 0 dB gain, so you can improve the NM by adding the antenna gain and the preamp gain, but you must subtract the Noise Figure of the preamp because it adds its own noise that reduces the SNR of your weak signals.

The factors that worry me the most are the trees, the condition of your equipment, and the possibility of overload.

KHIZ has a NM of 30.2 dB. If you add the antenna gain of 10 dB average you get 40.2 dB. If you then add the preamp gain of 25 dB, you are now at 65.2 dB. And finally, if you add the DA gain of 15 dB you arrive at 80.2 dB NM. Your tuner might not like that.

http://forum.tvfool.com/attachment.p...1&d=1433873272

Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html

Try the new antenna first without a preamp. Then add a preamp. Don't add a distribution amp (DA) unless necessary.

Preamps to consider: Antennas Direct Juice, CM 7778, RCA TVPRAMP1R.

The Juice doesn't have an FM filter, but I don't see any strong FM signals in your area. You could always add a filter later. The CM is redesign. When PCT bought out Channel Master, they redesigned the 7777 and the 7778 but they didn't change the model numbers,

michaelt84 11-Jun-2015 5:43 AM

Thanks for the great analysis and reply, rabbit73 ... and you are correct that I don't need KHIZ. I hadn't paid attention to the noise margin of the stations ... the -7.1 dB for KCBS indicates that it's the one that I periodically lose.

I will try the Winegard HD7698P by itself and compare the signal strength for KCBS with and without the pre-amp.

I plan on mounting the OTA antenna to a roof-mounted 2" rigid conduit (outside diameter 2 3/8"), which also will hold a DirecTV dish. Here's a picture of the pole:

Rigid conduit mounting pole

Since the pole is so big and the mast clamp on the antenna only goes up to 2" OD, I think I need something like these for mounting:

Ronard 8200 vent pipe clamp
Galvanized 1 5/8" pipe

Is this the way to go, or is there a better way to mount the HD7698P?

The satellite dish points to 136°, the antenna will point to 81°. I will have only two to three feet of separation, but since they are so directional and offset by 55°, I'm hoping that I won't have any interference between the dish and the antenna. Does this look OK, or do you think I'll need more separation?

mikelessard 11-Jun-2015 2:31 PM

Denny's HD Stacker would be a good fit for this application. It's a powerful antenna with good gain and it's only 6' long. $129 incl shipping

http://www.dennysantennaservice.com/...enna-html.html

ADTech 11-Jun-2015 2:49 PM

The Stacker has low VHF elements that are useless for this location. Not a very good match. Besides, the seller refuses to provide any technical data on it (he likely doesn't have any) so no one out there really has any idea what its true performance characteristics actually are.

Stick with the 7-51 or 7-69 recommendation.

mikelessard 11-Jun-2015 3:36 PM

I think the reviews speak for themselves. It's uniquely well designed and fits a good niche. The gain figures come in around 13, the same as the other high end fringe combos. And it's only 6' long! So what if it has VHF low. You should be more careful what you say about your competition. Isn't going to make me rush out and buy your stuff.

michaelt84 12-Jun-2015 2:33 AM

I think this additional request may have gotten buried in the Stacker "discussion"; I appreciate everyone's effort to be helpful and will write it off to some people liking chocolate ice cream and others liking rocky road.

If anyone has the desire to provide some additional help, I'll try again:

I plan on mounting the OTA antenna to a roof-mounted 2" rigid conduit (outside diameter 2 3/8"), which also will hold a DirecTV dish. Here's a picture of the pole:

Rigid conduit mounting pole

Since the pole is so big and the mast clamp on the antenna only goes up to 2" OD, I think I need something like these for mounting:

Ronard 8200 vent pipe clamp
Galvanized 1 5/8" pipe

Is this the way to go, or is there a better way to mount the HD7698P?

The satellite dish points to 136°, the antenna will point to 81°. I will have only two to three feet of separation, but since they are so directional and offset by 55°, I'm hoping that I won't have any interference between the dish and the antenna. Does this look OK, or do you think I'll need more separation?

Billiam 12-Jun-2015 11:35 AM

Quote:

Originally Posted by mikelessard (Post 51619)
I think the reviews speak for themselves. It's uniquely well designed and fits a good niche. The gain figures come in around 13, the same as the other high end fringe combos. And it's only 6' long! So what if it has VHF low. You should be more careful what you say about your competition. Isn't going to make me rush out and buy your stuff.

I don't work for AD and don't even own one of their antennas right now.

I did own a Stacker at one time. Compared it to other antennas. Yes, it is a good antenna but ultimately it does not work as well for very weak signals as the Antennacraft antennas that I have or the 91 XG.

The Antennacraft Y10-7-13 was able to receive a very weak real Ch. 7 when paired with a pre amp while the Stacker could not. And its gain on UHF was also weaker across the board than the MXU 59. HBU 55 (was also able to receive Ch. 7 when the Stacker and Winegard 7084 could not) and 91 XG.

Unless I somehow managed to assemble it wrong, the Stacker while good, ultimately does not have as much gain as the other antennas I have.

No static at all 12-Jun-2015 12:29 PM

Quote:

Originally Posted by Billiam (Post 51639)
The Antennacraft Y10-7-13 was able to receive a very weak real Ch. 7 when paired with a pre amp while the Stacker could not. . . . . HBU 55 (was also able to receive Ch. 7 when the Stacker and Winegard 7084 could not) and 91 XG.

Hi Billiam, did you ever test the Y10-7-13 against the HBU-55 on VHF-Hi? Sorry if kind of off topic.

ADTech 12-Jun-2015 12:56 PM

michael,

Your proposed mounting sounds like it should be okay. You might pick up a length of 1 1/2" EMT from your local home center and save on shipping cost. I'd be inclined to use two of those Ronard adapters spaced at least 24-36" apart since the 7698 is a very large antenna and will be subject to very substantial wind loading. Hopefully, that existing rigid pipe is securely mounted. You sure don't want the whole rig to come down in a storm!

Keeping the OTA antenna as far away as feasible from the dish should be a goal. The presence of the antenna won't affect the dish's reception, but the presence of the dish too close to the OTA antenna will affect it, probably in the form of distorted reception patterns and altered front/back or front/rear ratios. It shouldn't have much, if any, effect on the forward reception so it may not matter a great deal.

rickbb 12-Jun-2015 12:59 PM

Quote:

Originally Posted by michaelt84

The satellite dish points to 136°, the antenna will point to 81°. I will have only two to three feet of separation, but since they are so directional and offset by 55°, I'm hoping that I won't have any interference between the dish and the antenna. Does this look OK, or do you think I'll need more separation?


They need to separated by 3 feet at a minimum, more is better. Being directional and pointed in different directions won't help with interference. Just having big arrays of metal close to each other is where the interference comes from.

Billiam 13-Jun-2015 1:36 AM

Quote:

Originally Posted by No static at all (Post 51641)
Hi Billiam, did you ever test the Y10-7-13 against the HBU-55 on VHF-Hi? Sorry if kind of off topic.

Yes. The HBU 55 was only slightly better on real Ch. 7. Maybe a half db of gain. It also seemed to reject the co channel that was causing problems a wee bit better and both, far better than the YA1713 which could not even get a whiff of Ch. 7 despite being at the same height and using the same pre amp.


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