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NO OTA for me

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Anonymous
April 28, 2004 9:42:48 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

I use Cox Cable for my TV and internet service and after hearing that
Voom and DTV force you to get your local programing off of the air waves
I have decided that they will never get my business. I like the fact
that with cable, Everything comes in from the same source and when I can
get a few more cable networks in HD I will pick up their HD receiver.

BTW... for those of you who are pissed off about not getting any Wide
screen formatted PPV on DTV, almost all of the new releases on cox ON
DEMAND programing are in both 4:3 and wide screen.

I have no intention of using any service that forces me to use "rabbit
ears" to get my tv. dump you dish and get cable TV service.

More about : ota

Anonymous
April 28, 2004 11:14:03 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"No way" <no@way.com> wrote in message
news:%GNjc.14849$Jy3.947@fed1read03...
: I use Cox Cable for my TV and internet service and after hearing that
: Voom and DTV force you to get your local programing off of the air
waves
: I have decided that they will never get my business. I like the fact
: that with cable, Everything comes in from the same source and when I
can
: get a few more cable networks in HD I will pick up their HD receiver.
:
: BTW... for those of you who are pissed off about not getting any Wide
: screen formatted PPV on DTV, almost all of the new releases on cox ON
: DEMAND programing are in both 4:3 and wide screen.
:
: I have no intention of using any service that forces me to use "rabbit
: ears" to get my tv. dump you dish and get cable TV service.
:
===================
Sorry, but you are wrong.
The OTA is the best way to go.
Anonymous
April 28, 2004 1:31:27 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Agree that there are advantages in getting everything from the same source.

However, many do not realize that the newer HDTV tuners integrate cable,
OTA, and DirecTV. One programming guide, one channel selection switch.
When tuning you reallly don't care what the source is. One thing about OTA,
it is free, and with digital the reception for most is perfect.
--
"No way" <no@way.com> wrote in message
news:%GNjc.14849$Jy3.947@fed1read03...
> I use Cox Cable for my TV and internet service and after hearing that
> Voom and DTV force you to get your local programing off of the air waves
> I have decided that they will never get my business. I like the fact
> that with cable, Everything comes in from the same source
SNIP
Related resources
Anonymous
April 28, 2004 3:17:13 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Richard C. wrote:

> "No way" <no@way.com> wrote in message
> news:%GNjc.14849$Jy3.947@fed1read03...
> : I use Cox Cable for my TV and internet service and after hearing that
> : Voom and DTV force you to get your local programing off of the air
> waves
> : I have decided that they will never get my business. I like the fact
> : that with cable, Everything comes in from the same source and when I
> can
> : get a few more cable networks in HD I will pick up their HD receiver.
> :
> : BTW... for those of you who are pissed off about not getting any Wide
> : screen formatted PPV on DTV, almost all of the new releases on cox ON
> : DEMAND programing are in both 4:3 and wide screen.
> :
> : I have no intention of using any service that forces me to use "rabbit
> : ears" to get my tv. dump you dish and get cable TV service.
> :
> ===================
> Sorry, but you are wrong.
> The OTA is the best way to go.
>
>

While I agree that the original poster is "wrong" and OTA is still the
best way to go, be careful about such unsubstantiated claims. At
least give a few reasons why. For example:

1) OTA is free
2) OTA you get more local HDTV channels than through cable/sat
3) Some people's cable or sat providers don't even offer HD yet
4) Some people (me) use HDTV only over OTA and don't have cable.
Anonymous
April 28, 2004 7:29:06 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Agree, but the main problem is that TV antenna installation is sort of a
lost art. If you know what you are doing, it isn't that difficult to
determine the proper antenna setup. If the consumer finds out what he is
missing, perhaps some enterprising people will be found.

How was the analog reception on the antenna you tried?
>
> Just keep in mind that the antenna setup is not trivial. I tried recently
> tried OTA. Got a high gain UHF antenna. Put it on a 10' mast. Aimed it
> perfectly. Still got poor signal strength, and thus lots of digital
artifacts
> from data stream breakup. My house is not on a peak, but not in a valley
> either. All the sources are 10 to 20 miles away. ..
Anonymous
April 28, 2004 9:47:58 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Wed, 28 Apr 2004 05:42:48 -0700, No way <no@way.com> wrote:

>I use Cox Cable for my TV and internet service and after hearing that
>Voom and DTV force you to get your local programing off of the air waves
>I have decided that they will never get my business. I like the fact
>that with cable, Everything comes in from the same source and when I can
>get a few more cable networks in HD I will pick up their HD receiver.
>
>BTW... for those of you who are pissed off about not getting any Wide
>screen formatted PPV on DTV, almost all of the new releases on cox ON
>DEMAND programing are in both 4:3 and wide screen.
>
>I have no intention of using any service that forces me to use "rabbit
>ears" to get my tv. dump you dish and get cable TV service.

You're still getting local HDTV via OTA...
It just one step removed... via the cable co..
Oh.. and you get to pay extra $$ each month for the service.

Your cable co is supplying you local HDTV broadcasts using OTA
signals they received at one of the facilities.
Anonymous
April 29, 2004 12:05:04 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

I agree the installation is not for a homeowner. You should have an
installer that has the equipment to see the signal and to try and handle
multipath with a different antenna placement. Just a few inches in any
direction can make a world of difference.
I removed diplexers and found that some of my lost signal problems were
because of the diplexer.in the signal path. 99% of any installer will say
diplexing is industry standard and be correct. My situation was only found
because I switched from DirecTV to dish. I will not pay for digital form
the satellite providers yet. There is not enough content for now.
I am lucky in that Indy has many HD OTA signals, NBC,ABC,FOX,CBS,PAX etc.



"Joel Graffman" <JRGraff@bellsouth.net> wrote in message
news:%yTjc.50598$Uz1.19698@bignews3.bellsouth.net...
> Agree, but the main problem is that TV antenna installation is sort of a
> lost art. If you know what you are doing, it isn't that difficult to
> determine the proper antenna setup. If the consumer finds out what he is
> missing, perhaps some enterprising people will be found.
>
> How was the analog reception on the antenna you tried?
> >
> > Just keep in mind that the antenna setup is not trivial. I tried
recently
> > tried OTA. Got a high gain UHF antenna. Put it on a 10' mast. Aimed
it
> > perfectly. Still got poor signal strength, and thus lots of digital
> artifacts
> > from data stream breakup. My house is not on a peak, but not in a
valley
> > either. All the sources are 10 to 20 miles away. ..
>
>
Anonymous
April 29, 2004 4:15:23 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

"Michael J. Sherman" <msherman@dsbox.com> wrote in message news:<lgu4m1-kr6.ln1@developers.dsbox.com>...
> Richard C. wrote:
>
> > "No way" <no@way.com> wrote in message
> > news:%GNjc.14849$Jy3.947@fed1read03...
> > : I use Cox Cable for my TV and internet service and after hearing that
> > : Voom and DTV force you to get your local programing off of the air
> waves
> > : I have decided that they will never get my business. I like the fact
> > : that with cable, Everything comes in from the same source and when I
> can
> > : get a few more cable networks in HD I will pick up their HD receiver.
> > :
> > : BTW... for those of you who are pissed off about not getting any Wide
> > : screen formatted PPV on DTV, almost all of the new releases on cox ON
> > : DEMAND programing are in both 4:3 and wide screen.
> > :
> > : I have no intention of using any service that forces me to use "rabbit
> > : ears" to get my tv. dump you dish and get cable TV service.
> > :
> > ===================
> > Sorry, but you are wrong.
> > The OTA is the best way to go.
> >
> >
>
> While I agree that the original poster is "wrong" and OTA is still the
> best way to go, be careful about such unsubstantiated claims. At
> least give a few reasons why. For example:
>
> 1) OTA is free
> 2) OTA you get more local HDTV channels than through cable/sat

This isn't true for sat, as sat uses OTA for the locals, so you get
exactly the same thing.

> 3) Some people's cable or sat providers don't even offer HD yet

All sat companies, Direct, Dish, Voom offer many channels of HD in
addition to integrating locals via OTA through the same receiver.


> 4) Some people (me) use HDTV only over OTA and don't have cable.

If you can live with the limited choices, that's fine, but you're in a
shrinking minority.
Anonymous
April 29, 2004 12:58:27 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

>>4) Some people (me) use HDTV only over OTA and don't have cable.
>
>
> If you can live with the limited choices, that's fine, but you're in a
> shrinking minority.

My point is that I do not have cable. In order to watch HDTV I do not
want to have to shell out to the monopoly in my area just to get the
four HD channels they provide. Here in Northern VA I have exactly one
(1) cable company to choose from.

I have DISH network for standard programming anyways, but my point is
that I don't want to get cable just to get HD. That's why I use OTA
for HDTV.

The BIGGEST point that you so quickly glossed over is my first point:
OTA is free! Don't dismiss this in such an off-hand manner.

So I get satellite programming with local channels (non-HD) (DISH)
plus all the local HD stations (OTA) for a TOTAL monthly bill of $29.
Hard to beat that.
Anonymous
April 29, 2004 9:45:40 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

> I have no intention of using any service that forces me to use "rabbit
> ears" to get my tv. dump you dish and get cable TV service.
>

Satellite doesn't force you to use rabbit ears for anything they
offer.

Jeff B
Anonymous
April 30, 2004 3:40:16 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Wed, 28 Apr 2004 20:05:04 GMT, "Emil Luca" <e_lucaREMOVE@yahoo.com> wrote:

>I agree the installation is not for a homeowner. You should have an
>installer that has the equipment to see the signal and to try and handle
>multipath with a different antenna placement. Just a few inches in any
>direction can make a world of difference.
>I removed diplexers and found that some of my lost signal problems were
>because of the diplexer.in the signal path. 99% of any installer will say
>diplexing is industry standard and be correct. My situation was only found
>because I switched from DirecTV to dish. I will not pay for digital form
>the satellite providers yet. There is not enough content for now.
>I am lucky in that Indy has many HD OTA signals, NBC,ABC,FOX,CBS,PAX etc.

Shouldn't multipath be mostly gone with a highly directional antenna
pointed exactly at the source? But I can see direct signal strength
being affected by relatively small differences in placement. But more
on the order of several feet. With a house, your options are kind of
limited. If only my subdivision would let me put a 50 foot mast on
my roof! I would have to put lights on it to warn airplanes...
Anonymous
April 30, 2004 3:40:18 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Wed, 28 Apr 2004 15:29:06 -0400, "Joel Graffman" <JRGraff@bellsouth.net> wrote:

>Agree, but the main problem is that TV antenna installation is sort of a
>lost art. If you know what you are doing, it isn't that difficult to
>determine the proper antenna setup. If the consumer finds out what he is
>missing, perhaps some enterprising people will be found.
>
>How was the analog reception on the antenna you tried?

Analog reception is pretty good. And I do know what I am doing.
Used antennaweb.org to get the exact angle from my house to the
transmitter in question. In this case 189 degrees. I used the
tallest mast my subdivision would allow. Pointed it perfectly.
Used a relatively short run of RG-8 quad shield from the antenna
super low loss 300 to 75 ohm converter directly to the OTA ATSC
receiver. About 35 feet total. The antenna I chose has a gain
of 13.7dB and is highly directional. Could'a gotten a massively
large one with a gain of 16.7dB. But not sure that extra 3dB
would have done much better for me. And it would have been a
serious eye sore. Oh, these are UHF only antennas. What else
could a professional have done that I did not? I think the
problem is line of site. The channel is 47, fairly high freq.
And the tower is 20.9 miles away and broadcasting with a power
of only 107kW. Versus the usual of > 700kW. Clearly ATSC does
require a good bit more power than NTSC to get acceptable pickup.

My point was that OTA HD antenna setup has a very high "pain in
the ass" factor associated with it. Even if you do have some
skill installing one. Otherwise you have to pay someone alot
to handle the pain for you.
Anonymous
April 30, 2004 5:06:01 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

On 29 Apr 2004 23:40:18 -0500, George Thorogood
<thorogood@mailinator.com> wrote:

>On Wed, 28 Apr 2004 15:29:06 -0400, "Joel Graffman" <JRGraff@bellsouth.net> wrote:
>
>>Agree, but the main problem is that TV antenna installation is sort of a
>>lost art. If you know what you are doing, it isn't that difficult to
>>determine the proper antenna setup. If the consumer finds out what he is
>>missing, perhaps some enterprising people will be found.
>>
>>How was the analog reception on the antenna you tried?
>
>Analog reception is pretty good. And I do know what I am doing.
>Used antennaweb.org to get the exact angle from my house to the
>transmitter in question. In this case 189 degrees. I used the
>tallest mast my subdivision would allow. Pointed it perfectly.
>Used a relatively short run of RG-8 quad shield from the antenna
>super low loss 300 to 75 ohm converter directly to the OTA ATSC
>receiver. About 35 feet total. The antenna I chose has a gain
>of 13.7dB and is highly directional. Could'a gotten a massively
>large one with a gain of 16.7dB. But not sure that extra 3dB
>would have done much better for me. And it would have been a
>serious eye sore. Oh, these are UHF only antennas. What else
>could a professional have done that I did not? I think the
>problem is line of site. The channel is 47, fairly high freq.
>And the tower is 20.9 miles away and broadcasting with a power
>of only 107kW. Versus the usual of > 700kW. Clearly ATSC does
>require a good bit more power than NTSC to get acceptable pickup.
>
>My point was that OTA HD antenna setup has a very high "pain in
>the ass" factor associated with it. Even if you do have some
>skill installing one. Otherwise you have to pay someone alot
>to handle the pain for you.

It could be Signal overload from adjacent old style NTSC
transmitters. (pumping out a MW on a nearby freq). If your have an
attenuator insert it inline at 8VSB receiver input. Otherwise insert
an extra splitter or two before receiver.. Each two way reduces
signal at output by ~3.5db.. 4 way reduces signal output by ~7db.

Also do NOT, I repeat DO NOT, diplex Sat LNB outputs on the same
Coax with signals coming from in an antenna. Use a separate Coax
line.
Anonymous
April 30, 2004 8:58:00 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <rak390dfr9rue7fa1u5st44t6lroqc16du@4ax.com>,
George Thorogood <thorogood@mailinator.com> writes:
> On Wed, 28 Apr 2004 15:29:06 -0400, "Joel Graffman" <JRGraff@bellsouth.net> wrote:
>
> of only 107kW. Versus the usual of > 700kW. Clearly ATSC does
> require a good bit more power than NTSC to get acceptable pickup.
>
Given my own experience, ATSC requires approx 10X less power (-10dB)
of the NTSC power. One local ATSC station that transmits at 19kW
is 316kW on NTSC, and the reception is easier. Another one is
less than 1MW, while the NTSC channel is about 5MW.

The big problem is front end on one of my OTA ATSC receivers. It is
very finniky, and needs to be spoon fed the antenna signal within
about a +-10dB range to get all channels. This seems to be an issue
of overload with wide variation of signal levels (or something
like that.) It could also be a matching issue (where adding the pads
forces a better match.)

My other receiver is a little less finniky, but it looks like receiver
front end design is an afterthought. I wouldn't be surprised if the
frontends have very very poor matches, very poor selectivity and very
poor AGC. This is probably one reason why using a preamp with a pad
(almost 0dB gain) vastly improves my reception.

John
Anonymous
April 30, 2004 9:32:58 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Even with only 107KW you should get good reception with a modest antenna.
Since your antenna was hi-gain it was also highly directional and a few
degrees can make a large difference. Did you try varying the antenna
direction to account for the difference berween the true angle and your
compass indication?

--
"Tim Keating" <NotForJunkEmail@directinternet11.com1> wrote in message
news:sjm390hb6dillbi3j3csu5n3r3ln0h1s94@4ax.com...
> On 29 Apr 2004 23:40:18 -0500, George Thorogood
> <thorogood@mailinator.com> wrote:
>
> >Analog reception is pretty good. And I do know what I am doing.
> >Used antennaweb.org to get the exact angle from my house to the
> >transmitter in question. In this case 189 degrees.
Anonymous
April 30, 2004 1:44:14 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Fri, 30 Apr 2004 04:58:00 +0000 (UTC), toor@iquest.net (John S. Dyson) wrote:


>Given my own experience, ATSC requires approx 10X less power (-10dB)
>of the NTSC power. One local ATSC station that transmits at 19kW
>is 316kW on NTSC, and the reception is easier. Another one is
>less than 1MW, while the NTSC channel is about 5MW.

Given the nature of digital signals versus analog, that should be
the case. But definitely not my experience. I can not explain why.

>The big problem is front end on one of my OTA ATSC receivers. It is
>very finniky, and needs to be spoon fed the antenna signal within
>about a +-10dB range to get all channels. This seems to be an issue
>of overload with wide variation of signal levels (or something
>like that.) It could also be a matching issue (where adding the pads
>forces a better match.)

The built in signal strength meter has never shown overload. But
then again, this feature is software implemented in the digital
stage. Thus after the analog front end stage. So it could possibly
be "lying". What do you think?

>My other receiver is a little less finniky, but it looks like receiver
>front end design is an afterthought. I wouldn't be surprised if the
>frontends have very very poor matches, very poor selectivity and very
>poor AGC. This is probably one reason why using a preamp with a pad
>(almost 0dB gain) vastly improves my reception.

The receiver I have been using is a Samsung SIRT151. An older model.
Also a baseline model. Perhaps the newer SIRT351 would have a better
designed front end.
Anonymous
April 30, 2004 1:44:18 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Fri, 30 Apr 2004 05:32:58 -0400, "Joel Graffman" <JRGraff@bellsouth.net> wrote:

>Even with only 107KW you should get good reception with a modest antenna.
>Since your antenna was hi-gain it was also highly directional and a few
>degrees can make a large difference. Did you try varying the antenna
>direction to account for the difference berween the true angle and your
>compass indication?

I did not try antenuation. The signal strength meter built in to the
receiver still showed it as weak. Also did not try varying the angle.
The compass I got was very high quality. The analog signal looks just
beautiful. No ghosting at all that I can see. At this point, I am
not convinced very small scale tweaks will bring the signal strength
upto sufficient level to prevent breakup and other digital artifacts.

Looking at a local topology map, there is a low grade hill very close
to my house in the way. A few other land features between here and
the source. I definitely do not have line of site. So the signal
I am getting is whatever part is able to round the hills. At 669MHz
for channel 47 UHF, that does not appear to be much.

Again, my whole point, ATSC is a pain in the ass.
Anonymous
April 30, 2004 1:44:19 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

In article <94n490h3v6pjt9p1hq79s6p8e0shbfrql0@4ax.com>,
thorogood@mailinator.com says...
> On Fri, 30 Apr 2004 05:32:58 -0400, "Joel Graffman" <JRGraff@bellsouth.net> wrote:
>
> >Even with only 107KW you should get good reception with a modest antenna.
> >Since your antenna was hi-gain it was also highly directional and a few
> >degrees can make a large difference. Did you try varying the antenna
> >direction to account for the difference berween the true angle and your
> >compass indication?
>
> I did not try antenuation. The signal strength meter built in to the
> receiver still showed it as weak.

Digital tuners do not display signal strength. They display "singal
quality", which is the inverse of the bit error rate on the decoded
signal. Generally a stronger signal means a lower bit error rate,
which casues a higher signal quality reading. But the display does
*NOT* indicate strength directly, and does not enable one to evaluate
conditions such as overload directly.

This is a consequence of receiver design and large-scale chip
integration. The signal "strength" is not easy to externalize, while
the bit error rate is. And ultimately, low BER is what one wants.
Anonymous
April 30, 2004 5:31:38 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

George Thorogood (thorogood@mailinator.com) wrote in alt.tv.tech.hdtv:
> The channel is 47, fairly high freq.
> And the tower is 20.9 miles away and broadcasting with a power
> of only 107kW. Versus the usual of > 700kW. Clearly ATSC does
> require a good bit more power than NTSC to get acceptable pickup.

No, that's not true.

ATSC does probably need more than 107kW at channel 47 (although I receive
channel 51 from 18 miles away from a 150kW transmitter), but ATSC uses
far less power than NTSC at the same frequency.

A typical channel 47 NTSC transmitter is 5000kW, while the same channel on
ATSC is allocated 1000kW maximum, and it can generally be receive much more
clearly for much farther distances.

--
Jeff Rife | "I don't have to be Ray Liotta: movie star,
SPAM bait: | anymore. I can be Ray Liotta: Maya's boyfriend.
AskDOJ@usdoj.gov | All I want to do is regular, boring, ordinary
uce@ftc.gov | couple things."
| "Then you, sir, have hit the soul-mate lottery."
| -- Ray Liotta and Nina Van Horn, "Just Shoot Me"
Anonymous
April 30, 2004 5:37:59 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Tim Keating (NotForJunkEmail@directinternet11.com1) wrote in alt.tv.tech.hdtv:
> Also do NOT, I repeat DO NOT, diplex Sat LNB outputs on the same
> Coax with signals coming from in an antenna. Use a separate Coax
> line.

This just isn't true for 99% of cases.

It's trivially easy to try it both ways (use the satellite cable with
diplexers and use it as an OTA-only cable) to the same STB, and almost
everybody will find that the reception doesn't change for most channels.

Only the most marginal will be adversely affected by a correctly functioning
diplexer. And, if a diplexer causes problems, then a splitter will have
*far* more adverse affect.

Basically, the 1-2dB loss that a diplexer causes is not as important as
the 3.5-4.0dB loss for each splitter in the line.

--
Jeff Rife |
SPAM bait: | http://www.nabs.net/Cartoons/Dilbert/SalesToFriends.gif
AskDOJ@usdoj.gov |
uce@ftc.gov |
Anonymous
April 30, 2004 5:42:49 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

Chris Thomas (cthomas@mminternet.com) wrote in alt.tv.tech.hdtv:
> Digital tuners do not display signal strength. They display "singal
> quality", which is the inverse of the bit error rate on the decoded
> signal. Generally a stronger signal means a lower bit error rate,
> which casues a higher signal quality reading. But the display does
> *NOT* indicate strength directly, and does not enable one to evaluate
> conditions such as overload directly.

All true, and even raw signal strength meters may not be helpful, since
carrier-to-noise ratio (C/N) is the real measure of whether you will
recieve the data. It will also tell you just how much above the minimum
threshold you are, which will help to determine if the signal is "iffy".

The only consumer-priced device I know of that has this sort of a meter
is the MIT MyHD cards. This meter is the form of an extra optional program
that shows you C/N and bit-error rate.

--
Jeff Rife |
SPAM bait: | http://www.nabs.net/Cartoons/ArloNJanis/ClothesHorse.gi...
AskDOJ@usdoj.gov |
uce@ftc.gov |
Anonymous
May 1, 2004 12:22:25 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Fri, 30 Apr 2004 13:37:59 -0400, Jeff Rife <wevsr@nabs.net> wrote:

>Tim Keating (NotForJunkEmail@directinternet11.com1) wrote in alt.tv.tech.hdtv:
>> Also do NOT, I repeat DO NOT, diplex Sat LNB outputs on the same
>> Coax with signals coming from in an antenna. Use a separate Coax
>> line.
>
>This just isn't true for 99% of cases.
>
>It's trivially easy to try it both ways (use the satellite cable with
>diplexers and use it as an OTA-only cable) to the same STB, and almost
>everybody will find that the reception doesn't change for most channels.
>
>Only the most marginal will be adversely affected by a correctly functioning
>diplexer. And, if a diplexer causes problems, then a splitter will have
>*far* more adverse affect.
>
>Basically, the 1-2dB loss that a diplexer causes is not as important as
>the 3.5-4.0dB loss for each splitter in the line.

It is not a loss issue...

It is a harmonic bleed over issue between comparatively strong LNB
outputs and much weaker OTA signals.
Anonymous
May 1, 2004 3:20:23 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

Tim Keating (NotForJunkEmail@directinternet11.com1) wrote in alt.tv.tech.hdtv:
> >Basically, the 1-2dB loss that a diplexer causes is not as important as
> >the 3.5-4.0dB loss for each splitter in the line.
>
> It is not a loss issue...
>
> It is a harmonic bleed over issue between comparatively strong LNB
> outputs and much weaker OTA signals.

This is even less of a problem.

Most of the diplexers use filters that have the "wrong" signal down by 40dB
or so. If a signal that low is a problem, you have other problems to worry
about...like adjacent channel interference or even strong FM signals if you
get a digital channel 6 or 7.

In my case, doing the test I mentioned with and without diplexers on the same
piece of cable, the difference in C/N on OTA channels was about -0.5dB with
diplexers compared to without. If harmonics and bleedover were truly a
problem, it would show up in *all* cases...even when the OTA signals are
strong. Yet strong or weak C/N to begin with resulted in less than -1dB C/N
difference after inserting diplexers.

Very few people seem to have done real-world measurments on what diplexers
do to signal quality, but universally everyone that has done the measurements
shows that it is insignificant compared to other issues.

--
Jeff Rife |
SPAM bait: | http://www.nabs.net/Cartoons/OverTheHedge/HighTech.gif
AskDOJ@usdoj.gov |
uce@ftc.gov |
May 3, 2004 4:03:19 AM

Archived from groups: alt.tv.tech.hdtv (More info?)

On 29 Apr 2004 23:40:18 -0500, George Thorogood
<thorogood@mailinator.com> wrote:

>On Wed, 28 Apr 2004 15:29:06 -0400, "Joel Graffman" <JRGraff@bellsouth.net> wrote:
>
>>Agree, but the main problem is that TV antenna installation is sort of a
>>lost art. If you know what you are doing, it isn't that difficult to
>>determine the proper antenna setup. If the consumer finds out what he is
>>missing, perhaps some enterprising people will be found.
>>
>>How was the analog reception on the antenna you tried?
>
>Analog reception is pretty good. And I do know what I am doing.
>Used antennaweb.org to get the exact angle from my house to the
>transmitter in question. In this case 189 degrees. I used the
>tallest mast my subdivision would allow. Pointed it perfectly.
>Used a relatively short run of RG-8 quad shield from the antenna
>super low loss 300 to 75 ohm converter directly to the OTA ATSC
>receiver. About 35 feet total. The antenna I chose has a gain
>of 13.7dB and is highly directional. Could'a gotten a massively
>large one with a gain of 16.7dB. But not sure that extra 3dB
>would have done much better for me. And it would have been a
>serious eye sore. Oh, these are UHF only antennas. What else
>could a professional have done that I did not? I think the
>problem is line of site. The channel is 47, fairly high freq.
>And the tower is 20.9 miles away and broadcasting with a power
>of only 107kW. Versus the usual of > 700kW. Clearly ATSC does
>require a good bit more power than NTSC to get acceptable pickup.
>
>My point was that OTA HD antenna setup has a very high "pain in
>the ass" factor associated with it. Even if you do have some
>skill installing one. Otherwise you have to pay someone alot
>to handle the pain for you.


SORRY, but you have confused me. Why would you use RG-8, 50 ohm cable
anywhere in a 300/75 ohm system? your post looks like you fed the
output of a (75 ohm) tv antenna into 50 ohm RG-8 them into a 300 to 75
ohm converter into the tv? Your didnt mention if the antenna had a 75
ohm or 300 ohm output, but since you got coax connected I'll assume it
had an F connector. BUT Isnt that 50 ohm cable going to cause a big
mismatch and loss? Why not use RG6 straight from antenna 75 ohm out
put to the TV input? And I dunno about putting a 300 ohm to 75 ohm
converter as a termination on RG8. Either you really confused me or I
just dont understand. Sorry.

Dave
Anonymous
May 3, 2004 12:23:07 PM

Archived from groups: alt.tv.tech.hdtv (More info?)

On Mon, 03 May 2004 00:03:19 GMT, dave@aaahawk.com wrote:

Oops. RG-6 quad shield. The antenna has a 300 ohm output.
But there is a 300 to 75 ohm super low loss converter right there.


>SORRY, but you have confused me. Why would you use RG-8, 50 ohm cable
>anywhere in a 300/75 ohm system? your post looks like you fed the
>output of a (75 ohm) tv antenna into 50 ohm RG-8 them into a 300 to 75
>ohm converter into the tv? Your didnt mention if the antenna had a 75
>ohm or 300 ohm output, but since you got coax connected I'll assume it
>had an F connector. BUT Isnt that 50 ohm cable going to cause a big
>mismatch and loss? Why not use RG6 straight from antenna 75 ohm out
>put to the TV input? And I dunno about putting a 300 ohm to 75 ohm
>converter as a termination on RG8. Either you really confused me or I
>just dont understand. Sorry.
>
>Dave
!