Sign in with
Sign up | Sign in
Your question

OTA antenna question

Last response: in Home Theatre
Share
March 13, 2005 8:36:23 PM

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

Does anyone multiplex antennas? Maybe that's not the correct term. I
want to stack different antennas so I don't need a rotator. Where do I
find good information on how to do this correctly?
Clay

--


There are 10 kinds of people in the world:
Those who understand binary, and those who don't.

More about : ota antenna question

Anonymous
March 13, 2005 8:36:24 PM

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

"Badger" <cferriola@gmail.com> wrote in message
news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> Does anyone multiplex antennas? Maybe that's not the correct term. I
> want to stack different antennas so I don't need a rotator. Where do I
> find good information on how to do this correctly?
> Clay
>
You can mix the outputs of two or antennas by using a splitter in reverse,
that is, connect an antenna to each of the multiple outputs, and the cable
to the TV to the single input. This will work in cases where you don't try
to combine TV signals on adjacent channels (like channels 2 and 3). The
problem with adjacent channels is that the signal on one channel will spill
over and cause interference to the adjacent channel.

To mix adjacent channels, you will need a combiner, which is a more
expensive piece of equipment. If the adjacent channels are digital, you may
be able to mix them with a splitter.
Anonymous
March 13, 2005 8:36:24 PM

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

"Badger" <cferriola@gmail.com> wrote in message
news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> Does anyone multiplex antennas? Maybe that's not the correct term. I
> want to stack different antennas so I don't need a rotator. Where do I
> find good information on how to do this correctly?
> Clay
>
It's possible to combine multiple antennas together but the better option is
to use a non directional antenna. When you combine you loose more than the
3db insertion loss of the splitter/combiner. Winegard or Channel master
makes a single channel combiner that eliminates these problems. It's about
$29.00 and you have to order by channel. The other option is to trap out
the channel with a $30.00 trap connected in series with the OTHER antenna
line.

When you try for anything other than option one, a nondirectional antenna,
you create potential headaches. For my building I have three antennas, 10
traps and a combiner along with UHF/VHF splitters and FM traps. Total cost
about $500. But mine is a special "worst case" situation.
Related resources
Can't find your answer ? Ask !
Anonymous
March 13, 2005 8:36:25 PM

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

"Blue Cat" <bluecat22@go.com> wrote in message
news:Un%Yd.44479$%Y4.37044@bignews6.bellsouth.net...
>
> "Badger" <cferriola@gmail.com> wrote in message
> news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> > Does anyone multiplex antennas? Maybe that's not the correct term. I
> > want to stack different antennas so I don't need a rotator. Where do I
> > find good information on how to do this correctly?
> > Clay
> >
> You can mix the outputs of two or antennas by using a splitter in reverse,
> that is, connect an antenna to each of the multiple outputs, and the cable
> to the TV to the single input. This will work in cases where you don't try
> to combine TV signals on adjacent channels (like channels 2 and 3). The
> problem with adjacent channels is that the signal on one channel will
spill
> over and cause interference to the adjacent channel.
>
> To mix adjacent channels, you will need a combiner, which is a more
> expensive piece of equipment. If the adjacent channels are digital, you
may
> be able to mix them with a splitter.

Using a splitter to combine signals is never a good idea, even if the
channels are not adjacent for several reasons. Use the right equipment to
avoid problems.

Leonard
March 13, 2005 10:03:45 PM

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

"Leonard Caillouet" <no@no.com> wrote in

> Using a splitter to combine signals is never a good idea, even if
the
> channels are not adjacent for several reasons. Use the right
equipment to
> avoid problems.
>
> Leonard

OK, I agree. What is this equipment?
Clay
Anonymous
March 13, 2005 10:03:46 PM

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

"Badger" <cferriola@gmail.com> wrote in message
news:l80Zd.25329$_i3.816259@twister.southeast.rr.com...
>
> "Leonard Caillouet" <no@no.com> wrote in
>
> > Using a splitter to combine signals is never a good idea, even if
> the
> > channels are not adjacent for several reasons. Use the right
> equipment to
> > avoid problems.
> >
> > Leonard
>
> OK, I agree. What is this equipment?
> Clay

Combiners designed for the channels used, traps to eliminate the unwanted
channels and multipath. Check with Channel Master or Winegard. They should
have the right equipment.

Leonard
March 13, 2005 11:55:27 PM

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

"Jeff Rigby" <jffg2@comcast.net> wrote in message
news:1tadnQuQVoMNCKnfRVn-rg@comcast.com...
>
> "Badger" <cferriola@gmail.com> wrote in message
> news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> > Does anyone multiplex antennas? Maybe that's not the correct term.
I
> > want to stack different antennas so I don't need a rotator. Where
do I
> > find good information on how to do this correctly?
> > Clay
> >
> It's possible to combine multiple antennas together but the better
option is
> to use a non directional antenna. When you combine you loose more
than the
> 3db insertion loss of the splitter/combiner. Winegard or Channel
master
> makes a single channel combiner that eliminates these problems. It's
about
> $29.00 and you have to order by channel. The other option is to
trap out
> the channel with a $30.00 trap connected in series with the OTHER
antenna
> line.
>
> When you try for anything other than option one, a nondirectional
antenna,
> you create potential headaches. For my building I have three
antennas, 10
> traps and a combiner along with UHF/VHF splitters and FM traps.
Total cost
> about $500. But mine is a special "worst case" situation.
>
>
Well I thought about this option of Omnidirectional but no one I have
seen has one that will handle the distance from the transmitter. I am
68 to 100 miles from the stations.
What antenna would you recommend?
The good part is that the antenna only needs to aim in two directions.
Hence the idea to stack.

Clay
Anonymous
March 13, 2005 11:55:28 PM

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

R O T O R
"Badger" <cferriola@gmail.com> wrote in message
news:3N1Zd.7107$nZ.655096@twister.southeast.rr.com...
>
> "Jeff Rigby" <jffg2@comcast.net> wrote in message
> news:1tadnQuQVoMNCKnfRVn-rg@comcast.com...
>>
>> "Badger" <cferriola@gmail.com> wrote in message
>> news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
>> > Does anyone multiplex antennas? Maybe that's not the correct term.
> I
>> > want to stack different antennas so I don't need a rotator. Where
> do I
>> > find good information on how to do this correctly?
>> > Clay
>> >
>> It's possible to combine multiple antennas together but the better
> option is
>> to use a non directional antenna. When you combine you loose more
> than the
>> 3db insertion loss of the splitter/combiner. Winegard or Channel
> master
>> makes a single channel combiner that eliminates these problems. It's
> about
>> $29.00 and you have to order by channel. The other option is to
> trap out
>> the channel with a $30.00 trap connected in series with the OTHER
> antenna
>> line.
>>
>> When you try for anything other than option one, a nondirectional
> antenna,
>> you create potential headaches. For my building I have three
> antennas, 10
>> traps and a combiner along with UHF/VHF splitters and FM traps.
> Total cost
>> about $500. But mine is a special "worst case" situation.
>>
>>
> Well I thought about this option of Omnidirectional but no one I have
> seen has one that will handle the distance from the transmitter. I am
> 68 to 100 miles from the stations.
> What antenna would you recommend?
> The good part is that the antenna only needs to aim in two directions.
> Hence the idea to stack.
>
> Clay
>
>
Anonymous
March 14, 2005 3:29:28 AM

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

"Badger" <cferriola@gmail.com> wrote in message news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> Does anyone multiplex antennas? Maybe that's not the correct term.
> I want to stack different antennas so I don't need a rotator. Where
> do I find good information on how to do this correctly?
> Clay
>
You can do that with signal combiners from Channel Master and
others, but as other posters point out, you do lose signal strength,
so it works best with strong local stations.

A better solution is to bring the (possibly amplified) signal from
each antenna down on a separate coaxial cable and then let the
tuner automatically switch to whichever input has the best signal
on a channel-by-channel basis. Determining which antenna input
to use for each channel would be part of the automatic scanning
process which finds channels, and the input could be manually
modified later just like the rest of the channel setup information.

Unfortunately, I don't know of any tuner with more than two
antenna inputs, and even when two are present they may be
limited to receiving only certain types of signals, as opposed
to allowing any OTA signal from any antenna input.

Does anybody know of any tuner with this sort of advanced
antenna-switching capability? Thanks.
Anonymous
March 14, 2005 10:26:42 AM

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

"L David Matheny" <ldmnews1@netassoc.net> wrote in message
news:39klfdF62ujg8U1@individual.net...
> "Badger" <cferriola@gmail.com> wrote in message
news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> > Does anyone multiplex antennas? Maybe that's not the correct term.
> > I want to stack different antennas so I don't need a rotator. Where
> > do I find good information on how to do this correctly?
> > Clay
> >
> You can do that with signal combiners from Channel Master and
> others, but as other posters point out, you do lose signal strength,
> so it works best with strong local stations.
>
> A better solution is to bring the (possibly amplified) signal from
> each antenna down on a separate coaxial cable and then let the
> tuner automatically switch to whichever input has the best signal
> on a channel-by-channel basis. Determining which antenna input
> to use for each channel would be part of the automatic scanning
> process which finds channels, and the input could be manually
> modified later just like the rest of the channel setup information.
>
> Unfortunately, I don't know of any tuner with more than two
> antenna inputs, and even when two are present they may be
> limited to receiving only certain types of signals, as opposed
> to allowing any OTA signal from any antenna input.
>
> Does anybody know of any tuner with this sort of advanced
> antenna-switching capability? Thanks.

If you have a problem with adjacent channels or multipath and you amplify
the signals without trapping the problems first, the tuner still has to deal
with them.

Leonard
Anonymous
March 14, 2005 11:56:18 AM

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

"Jim Riggs" <oljim@islc.net> wrote in message
news:D 12kvh020od@enews4.newsguy.com...
>R O T O R
> "Badger" <cferriola@gmail.com> wrote in message
> news:3N1Zd.7107$nZ.655096@twister.southeast.rr.com...
>>
>> "Jeff Rigby" <jffg2@comcast.net> wrote in message
>> news:1tadnQuQVoMNCKnfRVn-rg@comcast.com...
>>>
>>> "Badger" <cferriola@gmail.com> wrote in message
>>> news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
>>> > Does anyone multiplex antennas? Maybe that's not the correct term.
>> I
>>> > want to stack different antennas so I don't need a rotator. Where
>> do I
>>> > find good information on how to do this correctly?
>>> > Clay
>>> >
>>> It's possible to combine multiple antennas together but the better
>> option is
>>> to use a non directional antenna. When you combine you loose more
>> than the
>>> 3db insertion loss of the splitter/combiner. Winegard or Channel
>> master
>>> makes a single channel combiner that eliminates these problems. It's
>> about
>>> $29.00 and you have to order by channel. The other option is to
>> trap out
>>> the channel with a $30.00 trap connected in series with the OTHER
>> antenna
>>> line.
>>>
>>> When you try for anything other than option one, a nondirectional
>> antenna,
>>> you create potential headaches. For my building I have three
>> antennas, 10
>>> traps and a combiner along with UHF/VHF splitters and FM traps.
>> Total cost
>>> about $500. But mine is a special "worst case" situation.
>>>
>>>
>> Well I thought about this option of Omnidirectional but no one I have
>> seen has one that will handle the distance from the transmitter. I am
>> 68 to 100 miles from the stations.
>> What antenna would you recommend?
>> The good part is that the antenna only needs to aim in two directions.
>> Hence the idea to stack.
>>
>> Clay
What channels and in what direction?
Anonymous
March 14, 2005 12:44:26 PM

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

"Leonard Caillouet" <no@no.com> wrote in message
news:GP%Yd.63454$SF.25769@lakeread08...
>
> "Blue Cat" <bluecat22@go.com> wrote in message
> news:Un%Yd.44479$%Y4.37044@bignews6.bellsouth.net...
> >
> > "Badger" <cferriola@gmail.com> wrote in message
> > news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> > > Does anyone multiplex antennas? Maybe that's not the correct term. I
> > > want to stack different antennas so I don't need a rotator. Where do I
> > > find good information on how to do this correctly?
> > > Clay
> > >
> > You can mix the outputs of two or antennas by using a splitter in
reverse,
> > that is, connect an antenna to each of the multiple outputs, and the
cable
> > to the TV to the single input. This will work in cases where you don't
try
> > to combine TV signals on adjacent channels (like channels 2 and 3). The
> > problem with adjacent channels is that the signal on one channel will
> spill
> > over and cause interference to the adjacent channel.
> >
> > To mix adjacent channels, you will need a combiner, which is a more
> > expensive piece of equipment. If the adjacent channels are digital, you
> may
> > be able to mix them with a splitter.
>
> Using a splitter to combine signals is never a good idea, even if the
> channels are not adjacent for several reasons. Use the right equipment to
> avoid problems.
>
You may be right. The solution I was proposing involved a small expenditure
of money. I would rather try out something like this, rather than buy a set
of combiners at the start. Someone else proposed an antenna rotator, and I
use one at my house. It would work better than a splitter, and still be
relatively inexpensive.
March 15, 2005 5:10:12 AM

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

"Jeff Rigby" <jeffg212@comcast.net> wrote in message
news:9q2dnSShQrMdBajfRVn-sw@comcast.com...
>
> "Jim Riggs" <oljim@islc.net> wrote in message
> news:D 12kvh020od@enews4.newsguy.com...
> >R O T O R
> > "Badger" <cferriola@gmail.com> wrote in message
> > news:3N1Zd.7107$nZ.655096@twister.southeast.rr.com...
> >>
> >> "Jeff Rigby" <jffg2@comcast.net> wrote in message
> >> news:1tadnQuQVoMNCKnfRVn-rg@comcast.com...
> >>>
> >>> "Badger" <cferriola@gmail.com> wrote in message
> >>> news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> >>> > Does anyone multiplex antennas? Maybe that's not the correct
term.
> >> I
> >>> > want to stack different antennas so I don't need a rotator.
Where
> >> do I
> >>> > find good information on how to do this correctly?
> >>> > Clay
> >>> >
> >>> It's possible to combine multiple antennas together but the
better
> >> option is
> >>> to use a non directional antenna. When you combine you loose
more
> >> than the
> >>> 3db insertion loss of the splitter/combiner. Winegard or
Channel
> >> master
> >>> makes a single channel combiner that eliminates these problems.
It's
> >> about
> >>> $29.00 and you have to order by channel. The other option is to
> >> trap out
> >>> the channel with a $30.00 trap connected in series with the
OTHER
> >> antenna
> >>> line.
> >>>
> >>> When you try for anything other than option one, a
nondirectional
> >> antenna,
> >>> you create potential headaches. For my building I have three
> >> antennas, 10
> >>> traps and a combiner along with UHF/VHF splitters and FM traps.
> >> Total cost
> >>> about $500. But mine is a special "worst case" situation.
> >>>
> >>>
> >> Well I thought about this option of Omnidirectional but no one I
have
> >> seen has one that will handle the distance from the transmitter.
I am
> >> 68 to 100 miles from the stations.
> >> What antenna would you recommend?
> >> The good part is that the antenna only needs to aim in two
directions.
> >> Hence the idea to stack.
> >>
> >> Clay
> What channels and in what direction?
>
>

here's what I know

uhf channel 31 51Deg
vhf " 12 51Deg
uhf " 32 52Deg
uhf " 26 52deg
uhf " 45 52deg
uhf " 51 119deg
vhf " 2 119deg
uhf " 48 119deg
uhf " 20 119deg
vhf " 8 123deg

what are my options besides a rotator?

Thanks Guys.

Clay
Anonymous
March 15, 2005 9:46:18 PM

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

In article <8urZd.28118$_i3.1043045@twister.southeast.rr.com> "Badger"
<cferriola@gmail.com> writes:


>here's what I know

>uhf channel 31 51Deg
>vhf " 12 51Deg
>uhf " 32 52Deg
>uhf " 26 52deg
>uhf " 45 52deg
>uhf " 51 119deg
>vhf " 2 119deg
>uhf " 48 119deg
>uhf " 20 119deg
>vhf " 8 123deg

>what are my options besides a rotator?

Given the distance, not much (IMO).

The VHF channels, 2, 8 and 12, are going to require a long boom
multichannel VHF yagi and a good preamp.

By contrast, 70~110 miles is going to be quite a challenge for the UHF TV
channels. I'm having visions of dual (twin-stacked) multi-element corner
reflectors or some 96" parabolics. (Big mothers!) UHF line-of-sight
signals out there 100+ miles are likely to encounter sufficent earth
curvature issues as to require erecting a tower 70~80' and using some
expensive ultra low-loss rigid or semi-rigid feedline, i.e., some '500' or
'750' cable-tv trunk cable.

We can cover those distances on narrowband UHF communications equipment
with tall towers and high sensitivity (0.25 microvolt) receivers, but a
wideband TV receiver is stone deaf much below 25~30 microvolts. That's a
GOB of signal to try to pull in from 70~100+ miles out. Consider too that
many of the HD/SD TV transmitters are running on sharply reduced power
levels compared to their main analog signal.

I'm not saying it can't be done, but I doubt you will achieve any
consistency. And if you think it's tough now, just wait until the leaves
are on the trees.

Have you considered moving nearer to the mainstream of the culture?
Anonymous
March 16, 2005 9:46:03 AM

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

> >
>
> here's what I know
>
> uhf channel 31 51Deg
> vhf " 12 51Deg
> uhf " 32 52Deg
> uhf " 26 52deg
> uhf " 45 52deg
> uhf " 51 119deg
> vhf " 2 119deg
> uhf " 48 119deg
> uhf " 20 119deg
> vhf " 8 123deg
>
> what are my options besides a rotator?
>
8bay uhf antenna pointed in 51 degree direction. The Winegard 8 bay is very
directional and has excellent back end rejection. It also will pull in
upper channel VHF. U/V antenna pointed in the 119 degree angle. See
Antennaweb.org for size of antenna. Use good 1 ghz splitter/combiner then
antenna amp. Make sure you have a FM trap available as you might need an
additional trap before the amp. This is more of a problem with the VHF
antenna. In my case ALL antennas had too much FM on them.

Things in your favor, weak signal means less ghost problems.

If any channel is too strong it can cause the antenna amp to modulate the
other channels. This is particularly true of FM. This is a problem that
4th generation ATSC tuners can overcome.

Look for antenna amp that has high immunity to overdrive.

Ghosts should not be a problem for ATSC as long as they are at least 10 db
less than the original. The 8 bay solves this problem for you.

Antenna gain is directly related to how directional it is. For example a
omni directional antenna has no gain, the 8 bay is very directional and has
very high gain. Besides combiner loss if you hook multiple antennas
together to get 360 degree coverage your gain will decrease to -0-. If you
hook two very directional antennas together their gain is less reduced
Your problem is that directional vhf antennas are HUGE. So that's your weak
point.

A solution for this is to have two antenna amps, one for each direction.
Trap out the unwanted channels from each amp and then combine. This will
increase your gain

Best would be the two amp solution with three antennas, the 8 bay for
direction 51 degree and a 8 bay for direction 119 degree then combined with
a vhf antenna using a uhf/vhf splitter. This keeps the uhf from being
messed up by the u/v antenna that typically has poor uhf backend rejection.

You can see how the cost of an antenna system could rapidly increase in a
urban setting with multiple antennas required. With a $500 cost antenna
system I have 24 digital channels and 16 NTSC channels with no ghosts: $300
in traps, 4 antennas, two antenna amps, three u/v splitters, two FM traps in
addition to the traps built into the amps, one combiner and one 2 set
splitter.
Anonymous
March 17, 2005 11:24:27 PM

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

In article <OpOdnVstV_zigaXfRVn-qQ@comcast.com> "Jeff Rigby"
<jffg2@comcast.net> writes:




>You can see how the cost of an antenna system could rapidly increase in a
>urban setting with multiple antennas required. With a $500 cost antenna
>system I have 24 digital channels and 16 NTSC channels with no ghosts: $300
>in traps, 4 antennas, two antenna amps, three u/v splitters, two FM traps in
>addition to the traps built into the amps, one combiner and one 2 set
>splitter.

As for your antenna system, if it didn't all come crashing down from the
weight of ice on it last winter and if it managed to also survive the
March winds, then it simply isn't big enough.
Anonymous
March 20, 2005 10:34:35 PM

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

"Blue Cat" <bluecat22@go.com> wrote in message
news:7mhZd.27215$6g7.23665@bignews1.bellsouth.net...
>
> "Leonard Caillouet" <no@no.com> wrote in message
> news:GP%Yd.63454$SF.25769@lakeread08...
> >
> > "Blue Cat" <bluecat22@go.com> wrote in message
> > news:Un%Yd.44479$%Y4.37044@bignews6.bellsouth.net...
> > >
> > > "Badger" <cferriola@gmail.com> wrote in message
> > > news:rS_Yd.25074$_i3.802442@twister.southeast.rr.com...
> > > > Does anyone multiplex antennas? Maybe that's not the correct term. I
> > > > want to stack different antennas so I don't need a rotator. Where do
I
> > > > find good information on how to do this correctly?
> > > > Clay
> > > >
> > > You can mix the outputs of two or antennas by using a splitter in
> reverse,
> > > that is, connect an antenna to each of the multiple outputs, and the
> cable
> > > to the TV to the single input. This will work in cases where you don't
> try
> > > to combine TV signals on adjacent channels (like channels 2 and 3).
The
> > > problem with adjacent channels is that the signal on one channel will
> > spill
> > > over and cause interference to the adjacent channel.
> > >
> > > To mix adjacent channels, you will need a combiner, which is a more
> > > expensive piece of equipment. If the adjacent channels are digital,
you
> > may
> > > be able to mix them with a splitter.
> >
If the adjacent channels are both digital then there should be no problem
mixing them as digital stays within it's allotted frequency band much better
than analog does. In any case the chances of adjacent channels within 100
miles of each other is very small as the FCC doesn't allow that as a general
rule.

A problem occurs not if the channels are adjacent but if the directions to
the stations are too close together for two antennas but not enough for one.
The higher the freq the easier it is to solve with a very directional
antenna. This is an important point! If you have two antennas pointed only
20 degrees apart then ghost signals will be extremely large. A combiner is
a necessity in this case. A combiner traps out the signal from one antenna
and selects for it from the other.
Anonymous
March 21, 2005 11:04:10 AM

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

> If the adjacent channels are both digital then there should be no problem
> mixing them as digital stays within it's allotted frequency band much
> better
> than analog does. In any case the chances of adjacent channels within 100
> miles of each other is very small as the FCC doesn't allow that as a
> general
> rule.
It seems remarkable to me that adjacent channel problems seem to have gone
away for digital TV. West Palm Beach has both digital channels 27 and 28
with no apparent interference.
!