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-   -   Do new OTA antenna(s/e) improve over time? (http://forum.tvfool.com/showthread.php?t=13932)

ant 2-Dec-2013 7:45 PM

Do new OTA antenna(s/e) improve over time?
 
Like did they improve from last year at all, or are they mostly the same? How about since analog days? This is assuming those indoor and outdoor types.

Thank you in advance. :)

GroundUrMast 2-Dec-2013 8:15 PM

It sounds like your are asking, 'Are the antennas currently on the market better than those that were designed and sold more than a year ago?'

If that's a fair summation of your question, I'd have to say, "It depends on which antenna you're considering."

Given that the FCC gave real Channels 52 to 69 to other services (sold the bandwidth actually), there cold be some changes to UHF antenna design. However, few consumer grade antenna manufactures have brought new designs to market thus far.

The Antennas Direct DB2e, DB4e and DB8e are newer designs that concentrate their performance in the range of real channels 14 through 51. As a result, they outperform older designs that covered real channels 14 through 69 or really old designs that went all the way to real CH-83. The performance of these specific antennas is a dB or two better than the older comparable designs.

Though Winegard has a well earned reputation, I have not seen any of their large 'fringe' antennas get a redesign in several years. They still span the RCH-14 to RCH-69 range which leaves a dB or two of UHF gain 'on the table'. The same can be said of the Antennacraft and Channel Master lines. (Even the relatively new Master Piece line of antennas is spec'd to RCH-69)

There are no fantastic leaps in antenna performance on the market... Because the laws of physics have not suddenly changed. The old designs were pretty good, usually with little significant difference between their actual performance and what theory would suggest is possible.

ant 2-Dec-2013 9:06 PM

Quote:

Originally Posted by GroundUrMast (Post 40298)
It sounds like your are asking, 'Are the antennas currently on the market better than those that were designed and sold more than a year ago?'

If that's a fair summation of your question, I'd have to say, "It depends on which antenna you're considering."

Given that the FCC gave real Channels 52 to 69 to other services (sold the bandwidth actually), there cold be some changes to UHF antenna design. However, few consumer grade antenna manufactures have brought new designs to market thus far.

The Antennas Direct DB2e, DB4e and DB8e are newer designs that concentrate their performance in the range of real channels 14 through 51. As a result, they outperform older designs that covered real channels 14 through 69 or really old designs that went all the way to real CH-83. The performance of these specific antennas is a dB or two better than the older comparable designs.

Though Winegard has a well earned reputation, I have not seen any of their large 'fringe' antennas get a redesign in several years. They still span the RCH-14 to RCH-69 range which leaves a dB or two of UHF gain 'on the table'. The same can be said of the Antennacraft and Channel Master lines. (Even the relatively new Master Piece line of antennas is spec'd to RCH-69)

There are no fantastic leaps in antenna performance on the market... Because the laws of physics have not suddenly changed. The old designs were pretty good, usually with little significant difference between their actual performance and what theory would suggest is possible.

Yes, that was my question. Thank you. It is interesting to see the curved DB (design/type)s of antenna(s/e). I assume that just started. I used those indoor types, RCA ANT751R, and CM4228 since last year. It sounds like not much improved since then.

ant 3-Dec-2013 4:18 PM

How about OTA antenna(s/e) don't have 360 degrees design for transmitters are from all over and not specified direction?

ADTech 3-Dec-2013 5:47 PM

Quote:

Originally Posted by ant (Post 40331)
How about OTA antenna(s/e) don't have 360 degrees design for transmitters are from all over and not specified direction?

The only antenna that meets that requirement is a vertical dipole which is usually a short range antenna. Unfortunately for that idea, US TV broadcasting broadcasting uses horizontal polarization as its default so a vertical whip doesn't receive very much.

I've tested a number of antennas that claim to be "omni-directional" but they just aren't. One in particular, an RCA flat panel for indoor use, exhibited peaks and nulls separated by as much as 15-20 dB when rotated which is a long, long way from being "omni" or "all" directional.

teleview 3-Dec-2013 6:08 PM

If your reference is to Tv receiving antennas.

The omnidirectional antennas such as the , www.winegarddirect.com , MS1000 / MS2000.

Reception is the same now as in the past.

The advantage of a omnidirectional antenna is reception from all directions.

The disadvantage is omnidirectional antennas receive reflected signals , multi-path from all directions.
A Analog Tv picture , the reflected signals can be seen on the Tv screen as multiple images of the origionl image , called ghosts.

With Digital reception , the picture breaks up into blocks.

The issue , then and now is Signal Quality.

If Signal Quality is High , a low to no amount multi-path reflections the a omnidirectional antenna can work Ok for Digital Tv reception because Digital broadcast Tv tuners have built in equilizer computer circuits that correct the multi-path up to a certain degree.

The signal gain of a omnidirectional antenna is about the same as a simple dipole or loop antenna , so reception is local to midrange distance , strong to moderate signal strengths.

The understanding of electromagnetic communications is about the same now as in the past.

---------

A 'New' type of communications is being experminted with now.

Gravity Wave Communications.

Do not laugh or discount.

Many people in the past said there is no such as electromagnetic communications and humans will never fly.

teleview 3-Dec-2013 9:52 PM

+=>
-------
As to Vertical antenna reception.

Some Tv Broadcasters are transmitting , Circular and Eliptical , polerization.

www.rabbitears.info has a list of Tv stations that are transmitting , Eliptical and Circular.

A antenna in/of any position , vertical , horizontal , or any position between vertical and horizontal will receive Eliptical and Circular transmissions.

As a matter of fact , some Tv stations have been transmitting Circular and Eliptical polerization since the early days of television.

--------

FM Radio tramsmissions are , Eliptical and Circular.

teleview 4-Dec-2013 2:11 AM

Concerning Horizontal Vs. Vertical Polarization.

The following information is from my extensive library of television transmission and reception and related subjects.

From the book ,

TELEVISION STANDARDS AND PRACTICE

N.T.S.C.

FIRST EDITION

McGRAW-HILL BOOK COMPANY INC.

COPY WRIGHT YEAR 1943

--------
From page 316

The charge to Panel 9 read "considerations of the factors influencing the choice of polarization of the radiated wave." The conclusion reached by the Panel , that the polarization should be horizontal , is incorporated in the last of the N.T.S.C. Standards number 22.
Before arriving at this conclusion , the panel members concidered the effect of the direction of polarization in five basic categories: the effect (1) on the propagation of the television signal , (2) on the noise and interference , (3) on the design of receiving antennas , (4) on the design of transmitting radiators , and (5) on the relationship of the television sound service to the f-m broadcasting service.
The panel first decided that the direction of polarization chosen should apply to all television stations , since the evidence clearly showed that a single receiving aerial preformed best only on the direction of polarization for which it was designed. The panel also recommended that the same direction of polarization be employed for f-m broadcasting as for television sound.
The crux of the matter then remained the direction of polarization itself. On this matter , there were at first two sharply divided camps of opinion , favoring vertical and horizontal polarization , respective. By the time the Panel concluded its deliberations , however , sufficient evidence had been assembled to bring about substantial agreement that there was a slight preponderance of advantage for the horizontal direction.

--------
I find interesting the wording , a slight preponderance of advantage.

The chapter (x) goes on to explain the advantages and disadvantages of vertical and horizontal polarizations ,

In Easy to Understand Non Technical Terms. Practical and Useful.


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