Two Antennas for HDTV OTA?

Alan F:

Wikipedia: enter the station call letters

Nice tip. No wonder I can't get WRDC digital, they are only broadcasting
at 9.1 kW.

I'm confused about some stations that have two entries under Digital,
usually one listing at a low broadcasting strength and the other at a much
higher strength. What's the story on that?
e.g. WRAY
http://www.fcc.gov/fcc-bin/tvq?call=WRAY

--
Mac Cool

Mac Cool wrote:
Alan F:


Wikipedia: enter the station call letters


Nice tip. No wonder I can't get WRDC digital, they are only broadcasting
at 9.1 kW.

I'm confused about some stations that have two entries under Digital,
usually one listing at a low broadcasting strength and the other at a much
higher strength. What's the story on that?
e.g. WRAY
http://www.fcc.gov/fcc-bin/tvq?call=WRAY

If there are 2 entries for the digital channel, the station has been
operating under the low STA (Special Temporary Authority) power level
with an antenna that is often at a low height. The 2nd entry is a
construction permit or license to go full power when they are ready.

All "primary" broadcast stations (around 1800 across the US, IIRC)
were supposed to go full power on their digital signal this past summer
by July 1, 2006 UNLESS the station was granted a waiver or had a pending
construction permit on upgrading/building a broadcast tower. (As
background, the top four stations (basically the big four networks) in
the top 100 DMAs or markets were required to go full digital power by
July 1, 2005 although again waivers were granted.)

So some digital stations went full power back in June and early July.
But those working under construction permits were able to use it to drag
out the process a few months. AFAIK, there has been a steady stream this
year of stations putting up new antennas and/or installing new
transmitter gear and then going full power on the digital signal. But
the STA entry is still carried in the database for those stations. The
STA entry will probably be deleted eventually. Also, the FCC has
apparently granted a lot of waivers, so there are many stations in the
smaller markets who still have not gone full power on their digital
signal. I have not seen a count of how many stations are still at STA
power levels.

In the case of WRDC-DT, the FCC database shows the STA power of 9.1 KW
(which is not bad for STA for a UHF channel) and a construction permit.
If you can't receive the station OTA, email or call them to ask if they
are at full power and if not, when will they.

Alan F

Richard Minami wrote:
Hi! Does anyone know if I can run two roof top antennas concurrently? I
live between two metropolitan areas that are about 60 degrees apart. Can I
point one antenna to the north, and then use a splitter to add another
antenna pointing south west? Then I'd run the one cable into my HD
receiver. I've heard that analog signals may ghost because the two antennas
are receiving the signal at different angles. But would a digital broadcast
do the same thing? Thanks!

http://www.tvantenna.com/support/tut...combining.html


I did the above. Works great!

Make sure the leads from the antennas going into the splitter (diplexer)
are the same length.

My problem is that I am in the middle of a valley with TV towers visible
from all directions. I mounted two antennas vertically in opposite
directions on the same pole similar to the site below. I then went with
a digital tuner and get perfect reception on all channels.

Philip wrote:
Richard Minami wrote:
Hi! Does anyone know if I can run two roof top antennas
concurrently? I
live between two metropolitan areas that are about 60 degrees
apart. Can I
point one antenna to the north, and then use a splitter to add
another
antenna pointing south west? Then I'd run the one cable into my
HD
receiver. I've heard that analog signals may ghost because the
two antennas
are receiving the signal at different angles. But would a digital
broadcast
do the same thing? Thanks!

http://www.tvantenna.com/support/tut...combining.html


I did the above. Works great!

Make sure the leads from the antennas going into the splitter
(diplexer)
are the same length.

My problem is that I am in the middle of a valley with TV towers
visible
from all directions. I mounted two antennas vertically in opposite
directions on the same pole similar to the site below. I then went
with
a digital tuner and get perfect reception on all channels.

Great for you. I think that equal length thing only applies when the
antennas point the same direction to maintain phasing so the vertical
beam angle stays parallel with the booms. It certainly won't hurt to
have same length but I'm pretty sure it's unimportant when pointing in
different directions.

GG

On Thu, 30 Nov 2006 21:10:55 -0800, "Richard Minami"
wrote:

Hi! Does anyone know if I can run two roof top antennas concurrently? I
live between two metropolitan areas that are about 60 degrees apart. Can I
point one antenna to the north, and then use a splitter to add another
antenna pointing south west? Then I'd run the one cable into my HD
receiver. I've heard that analog signals may ghost because the two antennas
are receiving the signal at different angles. But would a digital broadcast
do the same thing? Thanks!

I'm doing it and it's working fine.
However, although they claim no ghosting because we don't see the
ghosts it's still a problem but does not manifest itself in the same
manner. Signals interfere be they analog or digital. With two
antennas you are likely to be receiving the same station with the
signal to one antenna a bit delayed from the other.

What I have found is that digital is not always a there or not there
thing. If you've ever seen a digital satellite signal fail due to
rain or snow the image may pixilate, it may break up into blocks, and
it may start pausing and then continuing. *Usually* the signal will
eventually fail. Also I have one station that I receive great with
one antenna. With both hooked up there isn't a sign of it.

IF you can do it you are better off with an A/B switch so you can
select the antennas for the best signal. If you do your station scan
with both antennas and find another station only on one, you can add
it manually. Some where (under the pile of parts) I have an
electronic A/B switch and would like to try that but having looked at
the innards I'm not at all impressed with it. Looks nice outside,
junk inside.

Unless stations are close I've not found an omni directional antenna
that works well although I do have a crossed dipole at 30 feet over my
shop that does well out to 30 or 40 miles, give or take. The two
antennas are closer to 90 feet and picking up stations out to about
100 miles.

Works for me, but I can only speak for my installation at my location.
It's not a case of YMMV, it's more than likely your mileage *will*
vary. :-))

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

In article ,
Roger wrote:

IF you can do it you are better off with an A/B switch so you can
select the antennas for the best signal.

If you are going to do this you may as well use a rotor.

I put in two antennae with a joiner (that costs 3db) because I wanted to
be able to get all the stations on my HD Tivo. In Pittsburgh, Ch 4-1 is
about 100 degrees away from all the other stations at my location.
Consequently, I could either program 4-1 or everything else. With two
antennae I get everything.

However, there is occasional break-up (pixilation) from weather and
other things beyond my control. I think this has more to do with
individual stations being able to put out a strong signal than anything
else.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

Robert Peirce wrote:
In article ,
Roger wrote:

IF you can do it you are better off with an A/B switch so you can
select the antennas for the best signal.

If you are going to do this you may as well use a rotor.

I put in two antennae with a joiner (that costs 3db) because I
wanted to
be able to get all the stations on my HD Tivo. In Pittsburgh, Ch
4-1 is
about 100 degrees away from all the other stations at my location.
Consequently, I could either program 4-1 or everything else. With
two
antennae I get everything.

However, there is occasional break-up (pixilation) from weather and
other things beyond my control. I think this has more to do with
individual stations being able to put out a strong signal than
anything
else.


An issue with a rotator is a second TV or recorder can't use the
stations not currently aimed at. Also, the rotator cost isn't much
different for another antenna.

GG

In article om,
"G-squared" wrote:

Robert Peirce wrote:
In article ,
Roger wrote:

IF you can do it you are better off with an A/B switch so you can
select the antennas for the best signal.

If you are going to do this you may as well use a rotor.

An issue with a rotator is a second TV or recorder can't use the
stations not currently aimed at. Also, the rotator cost isn't much
different for another antenna.

Why not spend a few bucks and get a device to join the two antennae
signals? That's what I did and it works fine. There is a 3db loss in
the joiner, but I still get great signal strength and I can program my
Tivo for any station I want.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

Do you have a URL for such a device? Thanks!
Richard


"Robert Peirce" wrote in message
...
In article om,
"G-squared" wrote:

Robert Peirce wrote:
In article ,
Roger wrote:

IF you can do it you are better off with an A/B switch so you can
select the antennas for the best signal.

If you are going to do this you may as well use a rotor.

An issue with a rotator is a second TV or recorder can't use the
stations not currently aimed at. Also, the rotator cost isn't much
different for another antenna.

Why not spend a few bucks and get a device to join the two antennae
signals? That's what I did and it works fine. There is a 3db loss in
the joiner, but I still get great signal strength and I can program my
Tivo for any station I want.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

Richard Minami wrote:
Do you have a URL for such a device? Thanks!
Richard


"Robert Peirce" wrote in message
...
In article om,
"G-squared" wrote:

Robert Peirce wrote:
In article ,
Roger wrote:

IF you can do it you are better off with an A/B switch so you can
select the antennas for the best signal.

If you are going to do this you may as well use a rotor.

An issue with a rotator is a second TV or recorder can't use the
stations not currently aimed at. Also, the rotator cost isn't much
different for another antenna.
Why not spend a few bucks and get a device to join the two antennae
signals? That's what I did and it works fine. There is a 3db loss in
the joiner, but I still get great signal strength and I can program my
Tivo for any station I want.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]




ChannelMaster Jointenna:
http://www.warrenelectronics.com/Antennas/joiners.htm