High Def Forum - Your High Definition Community & High Definition Resource

Go Back   High Def Forum - Your High Definition Community & High Definition Resource > Local HDTV Info & Reception > Local HDTV Info and Reception
Rules HDTV Forum Gallery LINK TO US! RSS - High Def Forum AddThis Feed Button AddThis Social Bookmark Button Groups

Local HDTV Info and Reception Learn about your local HDTV stations, availability, reception issues, OTA antennas and any other local issues. RSS - Local HDTV Info and Reception

91XG sensitivity of other direction?

Reply
AddThis Social Bookmark Button
 
Thread Tools
Old 03-29-2009, 02:58 AM   #1
High Definition is the definition of life.
 

Join Date: Mar 2009
Posts: 66
Default 91XG sensitivity of other direction?

It seems my 91XG does a fairly good job picking up stations opposite of where it is pointing,

does anyone know what the pattern looks like, is it reliable to get station in both directions?
PoorSignal is offline   Reply With Quote
Old 03-29-2009, 06:31 AM   #2
DIGITAL OTA is the KING!
 

Join Date: Jun 2008
Posts: 70
Default

I have found this plot, coutesy of hdtvprimer.com, to be very accurate. I have rotated my 91XG to the rear several times with these exact results! http://www.hdtvprimer.com/ANTENNAS/XG91.html

You must have strong stations to the rear. There is a huge falloff front to rear. In my case, when I had my antenna pointing at the weaker stations, the stronger stations that were 137 degrees to the rear were just strong enough to receive (they were about 30db stronger than the signal I was aiming at).

Bill
willscary is offline   Reply With Quote
Old 03-29-2009, 07:41 AM   #3
No Static At All
 
hoopitup2000's Avatar
 

Join Date: Mar 2008
Location: Northern Va
Posts: 798
Default

I find that the tuner makes a big difference with off-axis performance. One of my tuners provides dropout free reception of my stations @ 180 degrees, and another tuner doesn't. This is pretty much true of most of the stations in the green & yellow zones of TV FOOL.
hoopitup2000 is offline   Reply With Quote
Old 03-29-2009, 05:15 PM   #4
High Definition is the definition of life.
 

Join Date: Mar 2009
Posts: 1,311
Default

I confess, I find this thread of interest, but somehow, it does me zero good.

Like many people, I have a TVfool report that shows a set of strong stations clustered in one single direction, and then almost exactly 180 degrees off that aim is some other station or stations that we might or might not get. And then to add injury to insult, there may be some other stations almost 90 degrees off that best aim.

And it may be all well and fine to have a XG91 antenna or to contemplate buying one, and thus get that excellent willscarry pre published report on that specific antenna gain that covers a 360 degrees of arc for various television frequencies.

My problem is that I am one of those poor smucks that have no idea of what exact antenna I have. The antenna came with the house when I bought it in 1993. And not to bad mouth the antenna, its a rather large VHF UHF directional with some sort of Yagi elements. As I recall the seller told me it was the top of the line radio shack antenna circa 1992 or so, but I am not sure. As it is, even if the aim does not seem ideal, I get all the digital channels TVFool suggests I might get, including one 53 miles away most of the time and its almost 60 degrees off present aim.

And while I have done some ground things to improve digital reception, adding a post amp, not being 35 feet tall, I have yet to play with antenna aim.

Worse yet, I have nothing to quantify signal strength. I see some converter boxes report signal strength and maybe some HD ready TV's do also, but I have a pair of Sanyo HD ready LCD TV's and they seem to only report the raw number of digital and analog stations I can get at any given scan.

So the question being, not knowing exactly what antenna I now have, is there any measuring instruments that will give me more information than I have now? It sure would be nice to have a 360 arc gain report for my existing antenna.
__________________
High definition is not the definition of my life.
But knowledge is power and HD does have some potential to increase content variety and choices.
NonMcTubber is offline   Reply With Quote
Old 03-29-2009, 06:53 PM   #5
DIGITAL OTA is the KING!
 

Join Date: Jun 2008
Posts: 70
Default

Woah!

I am able to pick up stations from the rear because they are about 30db stronger than the ones I am pointing at and also because they happen to be a nearly perfect fit for the reception pattern of the 91XG. If I turn the antenna even a few degrees from optimal, I lose all reception to the rear.

For this reason, I use multiple antennas and jointennas to couple them.

I was only stating that it IS possible in some cases. It may not be possible in your case.

the other ideas may be much better solutions for you.

Bill
willscary is offline   Reply With Quote
Old 03-29-2009, 06:54 PM   #6
Administrator
 
rbinck's Avatar
 

Join Date: Apr 2004
Location: Katy, Texas
Posts: 16,001
Default

NonMcTubber that would probably be one of these:
VU-120XR.html
VU-90XR.html

The 120 is the largest RS made, I think.

Last edited by rbinck; 03-29-2009 at 06:57 PM.
rbinck is offline   Reply With Quote
Old 03-30-2009, 07:32 AM   #7
High Definition is the definition of life.
 

Join Date: Mar 2009
Posts: 1,311
Default

Thank you rbinck for posting those two radio shack models.

But now I doubt I have either of them, my antenna picture is similar to the radio shack model # VU-120XR except my antenna has eight pairs of large back elements and that pictured radio shack model had only seven. And the pictured 120 model show a drop piece parallel to the main boom in the center part of the antenna boom and my main boom lacks that. Otherwise the front yagi looks similar.

But who knows, maybe someone can post some set of possible antennas that might meet that 8 large back element description.

My other variable is that post 6/12/09, I will have three channels channels on VHF, at 9,11, and 13. The other 11 channels I get will be all UHF. And the only station I have which is about 180 degrees off main aim is fairly strong at almost 43 NM(dB) and only 20 miles away.
__________________
High definition is not the definition of my life.
But knowledge is power and HD does have some potential to increase content variety and choices.
NonMcTubber is offline   Reply With Quote
Old 03-30-2009, 05:09 PM   #8
How can anyone watch standard def?
 

Join Date: Jun 2008
Posts: 22
Default

The VU 190 is the biggest at 160"

Years ago there was a VU 210 that was even bigger.
baud is offline   Reply With Quote
Old 03-31-2009, 10:13 AM   #9
High Definition is the definition of life.
 

Join Date: Mar 2009
Posts: 1,311
Default

Quote:
Originally Posted by baud View Post
The VU 190 is the biggest at 160"

Years ago there was a VU 210 that was even bigger.
------------------------------------------------------------------------------
Well, even if baud did not hit the guess right either, it got me digging and in terms of the number of long boom and short boom elements on the yagi, I am a perfect match for a radio shack VU-160XR, even if it looks like the installer skipped installing the cradle boom.

I know, I know, these radio shack antennas are supposed to be flimsy and poorly constructed, but I did not choose it as it came with the house when I bought it, and after 15 years it appears to be in perfect shape.

Hopefully someone can post more data on its UHF pattern of reception off main aim because I a seem to be getting all available VHF stations.
__________________
High definition is not the definition of my life.
But knowledge is power and HD does have some potential to increase content variety and choices.
NonMcTubber is offline   Reply With Quote
Sponsored Links
Go Back   High Def Forum - Your High Definition Community & High Definition Resource > Local HDTV Info & Reception > Local HDTV Info and Reception
AddThis Social Bookmark Button
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads to 91XG sensitivity of other direction?
Thread Thread Starter Forum Replies Last Post
AntennasDirect 91XG crabby_bob Local HDTV Info and Reception 7 11-04-2011 11:10 PM
Clearstream4 vs. 91XG texastoker Local HDTV Info and Reception 3 03-04-2009 08:15 AM
Parabolic reflector for the 91XG? andyinsb Local HDTV Info and Reception 6 12-21-2008 11:00 AM
Televes DAT 75 toejam Local HDTV Info and Reception 13 10-09-2006 07:24 PM
Evening you can be an antenna guru bobbyv Local HDTV Info and Reception 4 05-03-2006 11:13 PM


All times are GMT -6. The time now is 02:22 AM.



Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2004 - 2008, High Def Forum