Archived from groups: alt.tv.tech.hdtv,alt.video.digital-tv (
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Charles Tomaras wrote:
>
> I really think you guys are putting too much energy into this and giving Bob
> way too much credit for whatever perceived negative influence you think he
> is having on the industry. The percentage of HDTV users and HDTV
> movers/shakers that read these posts is very small indeed when looking at
> the big picture. I'd be surprised if even 1% of the HDTV owners and
> potential buyers have ever even heard of Usenet.
>
>
Very true.
Something like AVSForum has a major negative affect on the decisions of
countless people who visit there. Here is a off the top of my head list
of what I think is impeding the 8-VSB digital transition in order of
importance IMO.
8-VSB does not work very well which generates .....
-Word of mouth among ordinary TV consumers that they should wait coming
from friends who have taken the plunge or who tried OTA and gave up. I
know plenty of those in New York City. Lots of word of mouth in New York
City that OTA simply doesn't work well enough to bother.
-Little enthusiasm by manufacturers and few manufacturers making receivers
-Less enthusiasm by retailers who take the hint from manufactures
lethargic actions
-Little enthusiasm by retailers who have a lot of receivers returned
over and over again. A friend here in New York took 9 receivers back to
WalMart before giving up. How would you feel about OTA 8-VSB receivers
if you managed that WalMart?
-Little enthusiasm by retailers and manufacturers above resulting in
little to no advertising for OTA receivers.
-All the above resulting in little training of retail sales about OTA,
instructions to stay away from OTA sales and actual salespersons making
negative pitches to customers on OTA.
-The fact that OTA generates less profits than a sale of satellite
subscription service.
-High price of OTA receivers. In the UK they hit a sweet spot of between
$50 and $100 and sales have skyrocketed. These receivers either work
with current rooftop antennas or with inexpensive indoor antennas.
-High price and need in most cases for rooftop antennas and their
installation cost.
-High price of HDTV sets though a lot of people seem willing to buy the
HDTV set and pass on the OTA receiver. Maybe because they are getting
satellite service which includes an OTA receiver. It would be
interesting to know how many who have satellite service bother to hook
up an antenna. I have come across numerous instances where they didn't
or didn't even know they had the possibility.
-Lack of HDTV programming.
-HDTV programming where HD is not that compelling.
- People doing due diligence with Google and hitting the words HDTV. The
complicated jargon, the endless learning curve about a dozen different
disciplines, the cult like atmosphere where if you don't know something
you are an outsider and if you have a problem you are beneath contempt
especially if after trying a dozen things that are suggested to you, you
still do not get decent reception. The feeling that if you are not
dedicating a major room to a home theater you are not doing it right.
-People doing a Google search and going to AVSForum. This is a great
place to get turned of of HDTV. You can come here all fired up and get
real turned off quick.
-A dozen other things I can't remember at the moment
-Bob Miller's rants on COFDM.
Here is a typical AVSForum "helper post" that will turn off most people
over 35....
Nitewatchman on AVSForum today....
http://www.avsforum.com/avs-vb/showthread.php?postid=5398203#post5398203
"Not to say you won't have problems no matter how much you go by the
"antenna 101 book", nevertheless I'm not at all surprised you are having
multipath problems with that setup ..... I assume by "Radio Shack"
combiner, you mean a hybrid 2 way splitter/combiner(i.e. a standard 2
way splitter used backwards), and not a VHF/UHF combiner(or "joiner")
such as CM #0549. The latter which would result in one antenna hooked to
its VHF input being used solely for VHF reception, the other antenna
hooked to UHF input on combiner would be used solely fir UHF reception
..... ?
If my assumption is correct, given that you are using different antenna
models then your antennas are certainly out of phase(at least on
some/many frequencies). To properly combine antennas onto the same feed
line into a "stacked array" of antennas for increased directivity(which
can be beneficial for multipath difficulties) and/or gain, you must do
all of the following :
#1). Use IDENTICAL antenna model(2 silver sensors for instance) for both
antennas
#2). you must have both antennas aimed in same direction and with the
"right" spacing/placement(1 wavelength apart at lowest frequency of use
is probably good) of antennas
#3). the coax feed from the combiner to each antenna has to be of the
exact same length
#4). the baluns(given a 300ohm antenna + the need for a balun to match
antenna to the 75 ohm unbalanced feedline(coax)) should be in phase with
each other.
Get any of those things wrong, and the antennas are out of phase, likely
increasing multipath on at least some frequencies/channels, perhaps
especially troublesome when dynamic multipath conditions(say when strong
winds blow the trees around which could cause the dynamic multipath
conditions at your location to be effected) are an issue.
What I mean by "out of phase" is -- the signal will arrive at one
antenna(or portion of the antenna/feedline system) at a slightly
different time than the other antenna ... other words, increasing
multipath ..... What you have set up is similiar to what we call "random
wire" antenna, which as you might imagine can produce quite
unpredictable results.
There is an excellent article on how to properly stack antennas at below
link -- I think that stacking antennas is probably most useful over a
narrow range of frequency(such as a single TV channel) with frequency
specific antennas rather than broadband antennas over a wide range of
frequencies(such as UHF TV band), although some here have reported
getting good results with a properly implemented stacked array of
broadband UHF antennas :
http://pages.cthome.net/fmdx/stackant.html
"
Can you imagine the newbie Joe Sixpack's reaction when he gets to the
line above, "Get any of those things wrong"....! And he or especially
his wife hears the ending without reading any further, "and your s**t
out of luck" coming in loud and clear".
Here is my idea of a post to help someone in the UK today.
"Charlie,
Get over to you local XXXXX market, they have a sale on XXXX OTA
receivers for $35, works great, just plug it in to your old antenna or
it may work fine on your $2 loop and your current Telly. Just put the
antenna by the window because the digital stations are at an average of
3.7 kW which is very low. You should be fine. There are 30 free channels
of DTV and 12 digital HD radio channels.
If that is not enough then you can sign up for TopUpTV for $15 for a
bunch of cable channels.
If it is HD you are looking for there is one and will be two more
satellites worth of HD over the coming year or so."
That is about what they are hearing in the UK and they do go out and buy
receives at the rate of 500,000 a month in a nation of 24 million
households.
Bob Miller
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