Bad Satellite Antenna

Thu Aug 4 19:40:26 CDT 2011

Hi All,

Many thanks to all who replied to my post.

Mark, you are correct about the LNB.  There is no external
 power.  The only connections are two F connectors.

The antenna problem has been repaired.  I thank all of you for your help.

Just for the record:  I bought a device called a "Coax
 Explorer" at Home Depot this morning.  I used the device to tone out the antenna transmission line.  I found it had no continuity.  Next, I traced the cable to the side of the house to a ground block (barrel connectors, with a ground
 bar).  I separated the F connectors, and again toned out the antenna line.  It (the transmission line) was good from the block to  the antenna.  About this time the satellite tech showed up.

He took the line, I had tested to the antenna, and connected it to a device to measure the satellite's signal strength.  His device could not "see" the satellite.  So, he replaced the LNB, and repositioned the antenna, after I cut down some branches he expressed concern over.  He said, with the new LNB, the satellite antenna was picking up a strong signal from the satellite.

After that, he replaced the ground block, and upgraded the ground system.  I had the TV on, and could see it coming back to normal through the window.  So all is now OK.

Thanks once again.

I wonder, if I would have had these problems had I turned off the satellite TV during the thunderstorm.

Best
 Wishes
Richard  

--- On Wed, 8/3/11, Mark Whittington <markwhi at gmail.com>
 wrote:

From: Mark
 Whittington <markwhi at gmail.com>
Subject: Re: Bad Satellite Antenna
To: "Richard" <revo753 at yahoo.com>
Cc: "Robert E. Seastrom" <rs at seastrom.com>, tacos at amrad.org
Date: Wednesday, August 3, 2011, 5:23 PM

I believe that the LNBs on current generation DBS systems is powered over the coax.
-Mark

On Wed, Aug 3, 2011 at 7:56 PM, Richard <revo753 at yahoo.com> wrote:

Hi All,

Robert, I think your question is great.

I wish: I could answer it.  When examining the LNB,
 I did not see any power wires, just the RF lines.  I have wondered, and do not understand how the LNB gets it's power.  Robert, anything you could say about this would help.

I have never had any experience with
 satellite antennas.  Last night I googled the words "satellite TV antennas" to learn something.  That is how I learned about the LNB.  Today I removed the LNB from the arm just to look it over.  I wrote down the
 numbers on it.  I also measured the antenna.  I do not know how these antennas are supposed to be measured, but across the dish horizontally I measured 18", and in the vertical direction, up and down the dish, I got
 191/2"

In looking over the LNB, I did not see any power wires or connections.  All I saw was two F type RF connectors.  One by one, each separately, I disconnected the F connectors, and examined them, then put them back.  I did not see any obvious damage.  

I tend to believe the LNB is bad due to lightening, which seemed very very close when this problem began.  I put my hands on the antenna, and it seemed solidly mounted, so I don't think it has moved, even thought the wind was strong.

The LNB has two RF lines coming out of it going to two different set-top boxes.  Both of these set top boxes say they can not "see" the satellite.  So, I think the problem is with the antenna, the LNB, the power to the LNB (I don't know how it get it's power.  Perhaps, I missed something, when I examined the LNB, as I did not fully remove it from the arm.)  Or perhaps the transmission cable from the
 antenna to
 the
 house is bad, but this seems unlikely.

Any help would be most appreciated.

I would like to learn about how this works, and get the system up and running.

Best Wishes
Richard Demaret
KI4KXJ

--- On Wed, 8/3/11, Robert E. Seastrom <rs at seastrom.com> wrote:

From: Robert E. Seastrom <rs at seastrom.com>
Subject: Re: Bad Satellite Antenna
To: "Richard" <revo753 at yahoo.com>

Cc: tacos at amrad.org
Date: Wednesday, August 3, 2011, 6:00 AM

Stupid question - is there power to the power injector that sends

juice to the LNB on the dish?

-r

Richard <revo753 at yahoo.com> writes:

>               

>  Hello,                                                                       
>  I am wondering if any of you have had a problem with a bad satellite         

>  antenna.  Last night we, in the Manassas area, had a  thunderstorm.  The     
>  picture on the satellite TV froze.  I rebooted the digital recorder set-top  
>  box.  It came back on.  I thought all was OK, and so continued watching
 my   
>  recorded programs.                                                           
>  Today, I found the the recorded programs is all I have. The set-top box says 
>  the antenna can not see the satellite.  We have two of these set-top boxes   

>  on two different TVs.  The result is the same on both of them.               
>  It would appear to me, the antenna is bad.  I looked it over a few hours     
>  ago, but could find nothing obviously physically wrong with it.              

>  I am wondering, if any of you have had a similar problem.           

>  Best Wishes                                                                  
>  73                                                                           
>  Richard Demaret                                                              

>  KI4KXJ                                   

>                                                                               
>
> _______________________________________________
> Tacos mailing list
> Tacos at amrad.org

> https://amrad.org/mailman/listinfo/tacos

_______________________________________________

Tacos mailing list

Tacos at amrad.org

https://amrad.org/mailman/listinfo/tacos

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://amrad.org/pipermail/tacos/attachments/20110804/971fd2b0/attachment.html>