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post #31 of 43 Old 12-18-2010, 06:43 AM
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1. Extended AD 91-XG & Winegard YA-1713 mounted to chimney.
2. No amplification
3. CM 9521A on UHF only. VHF fixed.
4. 1 TV connected at a time.
5. http://www.tvfool.com/?option=com_wr...da32a4c805032e
6.WWPB-DT--RF 44--69 miles--0.3 NM (Extreme tropo does rarely override this station)
LL
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post #32 of 43 Old 12-18-2010, 06:46 AM
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1. Winegard HD8800 UHF outdoor mounted
2. Channel Master 3041DSB
3. Channel Mst. 9521A
4. Two LCD sets & Convertor... Samsung, Dynex, Convertor Box Dig. Stream
5.http://www.tvfool.com/?option=com_wr...da3286d1a1d3d5
6. WUNK PBS Greenville, NC. WEPX is on such a short tower, it doesn't penetrate the trees but is closer.
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post #33 of 43 Old 12-23-2010, 04:50 PM
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1. Antenna model Winegard 7084P. Roof mounted.
2. Preamp: Motorola Signal Booster 484095-001-00 Bi-Directional RF Amplifier
3. Rotor used - Yes
4. Number of TV tuners connected: 4
5. http://www.tvfool.com/?option=com_wr...da32217bab1c09
6. Lowest reliable reception: CHCH-DT
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post #34 of 43 Old 12-23-2010, 06:59 PM
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Please don't take this the wrong way...this is in now way an indictment against anyone here, but I have to comment.

I am amazed at how many of you are not able to receive signals lower than +15 to +20 NM (dB). Perhaps I am lucky, or maybe delusional, but I always figured that I should be able to pick up a signal that was 0 NM (dB) or better with no problems and should actually be able to pick up signals inverse to my antenna gain. In other words, if I have 13 dBd of gain at a certain frequency, I should be able to reliably pick up that frequency if the signal is -13 NM (dB).

I know that this is not exact and there are MANY variables, but it has seemed to work for me in all of the locations I have erected outdoor antennas.

Just my opinion...any thoughts?
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post #35 of 43 Old 12-23-2010, 07:27 PM
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willscary: Bear in mind that things like loss due to long coax, imperfect antenna aiming (either accidental or to balance signals on a single aim), existence of sweet spots and dead spots, and all that can have an impact.

1) Winegard PR-8800 for UHF and AntennaCraft Y5-2-6 for VHF.
2) Radio Shack preamp.
3) Rotor exists for fine-tuning, not used day-to-day.
4) Tuners connected... 7 maybe? Most of them are in my room off my single downlead. Kitchen, office, sound room, my TV, my two computer tuners, and the spectrum analyzer when I'm home.

5) Link(s).
TVFool: http://www.tvfool.com/?option=com_wr...da32ce16a2121c
RabbitEars: http://www.rabbitears.info/search.ph...dBmV&height=44
(The latter is more accurate in my specific case. Except for WDRL, WSLS, and WSET for which I don't have an upper-VHF antenna, the strength numbers on RabbitEars closely match my spectrum analyzer.)

6) There are two ways to measure.
The general antenna aim produces signals down to WPXR. (This aim is required to balance WBRA and WSET.)
BUT, using the rotor to optimize for each station, I can barely decode WTLU and I decode WVIR with significant margin. WCAV decodes as a pixelated mess and 11 has a constant signal that won't decode, probably clashing of WTVD and WVPT.

- Trip

N4MJC

Comments are my own and not that of the FCC (my employer) or anyone else.

RabbitEars

"Ignorance and prejudice and fear walk hand in hand..." - Rush "Witch Hunt"

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post #36 of 43 Old 12-24-2010, 06:18 AM
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Trip,

I understand. My point, or rather, my question, was what is being done wrong? If coax runs are long and signals are split in several ways, an appropriate pre-amp should be used. Poor connections or old, RG59 coax should be replaced, including interior runs.

Perhaps I am wrong, but IF a location actually DOES have a +1 NM (dB) signal at a certain height, and an antenna that has a positive gain at the channel's frequency is placed at that height and aimed correctly, it should be received as long as the signal strength does not change. Cabling and distribution should be negated by pre-amplification and each receiver should have enough clean signal to reliably display the chosen channel.

I also understand that many people have aiming difficulties due to stations in many different directions. If you look at my original post in this thread, I use 5 antennas (pending the hook-up of a 6th - an additional attic mounted UHF antenna) connected via Jointennas. I need no rotor and all antennas are aimed for specific channels. For those who want to use only one antenna, I can understand the difficulties of receiving stations from different directions, but I still feel that it is POSSIBLE to capture much weaker signals with the same antenna in the same location with a little thought and elbow grease.

Trip, you are the expert and I like reading your posts. Do you really feel that a reception system that has positive gain, given a clean (no interference) signal, will not reliably decode and display a signal that is +1 NM (dB) at the antenna?
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post #37 of 43 Old 12-24-2010, 08:30 AM
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Quote:
Originally Posted by willscary View Post

Do you really feel that a reception system that has positive gain, given a clean (no interference) signal, will not reliably decode and display a signal that is +1 NM (dB) at the antenna?

My experience with an outdoor CM-4228 and 7777 preamp is UHF stations that model 7 dB NM or higher are fine, between +3 and -6.6 dB stations are intermittent. Except under unusual atmospheric condition receive nothing lower. Performance does not degrade precisely in the order modeled. Some stations that model weaker come in much better than those modeled higher. As the FAQ at TVfool points out modeling is at best a rough approximately of real world conditions.

Several things I've noticed:

1) We live on 13 acres in hilly NH, modeling by precise location yields significantly different results then by address.
2) TVfool uses FCC "license" and "construction permit" documents to model expected signal level. Once the FCC issues a construction permit TVfool uses that to calculate signal strength even though station may not yet be using the new transmitter/antenna. In our area about 2/3 of stations have either construction permits or pending applications.
3) Even though we have a roof mounted antenna it is lower than nearby trees. Longley-Rice models for terrain but it does not include nearby obstructions such as trees or buildings.
4) Longley-Rice modeling is statistical: calculated value is determined based percent of locations the percent of time signal will meet or exceed the predicted level. Not sure what values Andy and Trip use to model expected signal strength. Some of us will experience better reception then predicted and some of us unfortunately experience worse.

/tom

Fixed typo thanks arxaw. I'm using old style 4228. That is what happens when I try to quote model numbers from memory.
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post #38 of 43 Old 12-24-2010, 09:31 AM
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Quote:
Originally Posted by willscary View Post

Please don't take this the wrong way...this is in now way an indictment against anyone here, but I have to comment. I am amazed at how many of you are not able to receive signals lower than +15 to +20 NM (dB).

Well, first you need to take a walk in someone else's moccasins... In my case, +18 dB NM is the lowest received station with my *attic* mount. Yes, there are a few stations lower in NM but they are duplicates of what I already receive. They are receivable with a roof mount but it doesn't make sense to go after them, at least IMO.

Have a Merry Christmas!
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post #39 of 43 Old 12-24-2010, 10:07 AM
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I do understand both of the last two posts. I used to have attic mounted antennas as my main antennas. However, I could not reliably receive my locals because I live 40' below the top of a hill that is only about 300' away from my house. The hill is then covered by 100' tall pines and spruces. This hill is exactly in line with the transmitting towers nearly 40 miles away.

By building a 43' tall tower and getting the antennas outside, I went from intermittant dropouts in my 2 story, 25' AGL 120 yr old attic and 50-60% meter strength to 98-100% signal and perfect reception 24/7.

I guess what I am trying to say is that after about 2-1/2 years of seeing people in decent areas complaining about poor reception, my feeling is that where there is a will, there is a way.

My niece lives in a supposed "impossible" reception area, in a hole nearly 200' deep, with surrounding areas rising to peaks 1-2 miles away. A 35' tower got her antenna above her local treeline and a 91XG and CM7777, coupled with decent RG6 QS and a high quality 2-way splitter netted her 29 digital channels from Milwaukee, 62 miles away.

A friend of my parents has never had decent reception on top of his single story ranch. A 46' tower, a 91XG and a YA-1713, a CM7777 and new coax got him all of the locals over about 65 miles of hilly terrain.

I also understand that people in apartments, city dwellers in high multipath areas, people in mountainous regions, locations in deep wooded areas and people over 65 miles from the towers may have problems with reception. However, I see alot of people who have small antennas, poor or no pre-amps, suspect cabling and cheap splitters complain about a lack of signal.

Don't forget grounding benefits!

Actually, I really like this thread. I see it as an oppertunity to learn about difficulties in locations.
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post #40 of 43 Old 12-24-2010, 11:09 AM - Thread Starter
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Quote:
Originally Posted by Tschmidt View Post

My experience with an outdoor CM-8228 and 7777 preamp is UHF stations that model 7 dB NM or higher are fine, between +3 and -6.6 dB stations are intermittent. Except under unusual atmospheric condition receive nothing lower. Performance does not degrade precisely in the order modeled. Some stations that model weaker come in much better than those modeled higher.

Do you mean CM4228? Anyway, I have the 4228 old stye antenna (with screen removed) + 7777 preamp and reliably get KFTA 27 - NM 5.2dB. But you're right about modeling, there are a few stations on the list with slightly higher NMs than KFTA that I never get except during occasional tropo.
http://www.tvfool.com/?option=com_wr...7d52b50d23f641
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post #41 of 43 Old 12-24-2010, 11:46 AM
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Quote:
Originally Posted by willscary View Post


Actually, I really like this thread. I see it as an oppertunity to learn about difficulties in locations.

Every antenna install is a new experience; remember the ATSC tuner comes into play...I use my DISH 722 OTA tuner instead of the one built into the TV...I found the DISH to be more sensitive (especially on UHF)....and without a CM7777, the TV tuner would only see one local; ~20miles....the 722 tuner sees a UHF at ~35 miles away! So what works for one person wont be true for everyone or anyone else for that matter.....The use of a good lownoise preamp like a CM7777 is always recommened unless you can see the towers (LOS)...but sometimes too much signal is detrimental as well! In the digital world there is overload which did not exist too much in the analog mode unless you were right under the xmtr tower(s)..
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post #42 of 43 Old 06-10-2012, 11:30 PM
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1. Antennacraft D9000 at around 24ft above floor
2. No Preamp
3. Rotor used: Yes
4. 1 tuner (Magnavox TB100MW9)
5. http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d1349781473e3ae
6. WKAQ

I also don't see why some people can hit below 0NM (dB) and I thought my antenna was in very bad condition!
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post #43 of 43 Old 06-11-2012, 11:26 AM
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I didn't see this thread when it was created back in 2010. I would have had a different posting back then. This is what I had until December 2010:

Philips VHF/UHF/FM deep fringe combo antenna pointed at Chicago & Winegard HD-1080 for just WYIN pointed toward Cedar Lake, IN. Both antennas outside.

Preamp on just the Philips antenna, & was (still is) RCA model# TVPRAMP1R, & joined by the Winegard coupler model# CC7870

No rotor

2 TV's hooked to the antennas

TV Fool chart

WOCK-CD on RF 4 the lowest channel I can receive reliably (only because of the pre-amp, or WLS-TV on RF 7 would have been the lowest I could receive).


Since December 2010, my antenna array has changed. Now using the following antennas:

Antennacraft CS600 for VHF & Winegard HD9032 for UHF pointed at Chicago, & kept the Winegard HD-1080 for WYIN. All of them outside.

Same pre-amp, RCA model# TVPRAMP1R, but now switch is set to separate (Winegard HD-1080 remains unamplified), & the pre-amp & Winegard HD-1080 still combined by the Winegard coupler, model# CC7870.

Still no rotor

still 2 TV's hooked to the array.

Same TV Fool results.

WOCK-CD on RF 4 is still the lowest channel I receive. If I want to look at UHF, WYIN Gary, IN on RF 17 & WGN-TV on RF 19 are the lowest UHF stations I receive reliably (I only get WYIN in reliably, as long as I use the Winegard HD-1080, or the signal drops out constantly. WHNW-LD on RF 18 in Gary tends to interfere with WYIN from time to time.
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