Mfr error in Patriot dish???

[McGuyver]

I thought that some of you might find this interesting. What do you think about this? I have a 90cm Patriot dish that belonged to a friend, I installed it for her over 5 years ago, it was aimed at the 101W for only 3 channels. Then some time back a roofer had removed the dish to reroof her patio cover and obviously toasted the receiver, so I installed a new receiver and swapped my 90cm KTI 3ABN dish with her to save time and brought her old Patriot dish home to keep in exchange.

Today I set up the Patriot and discovered the LNB was also toasted so I installed a new one. Ok, so I aimed the dish the best I could at the 97W for testing but couldn't get more than about 32% QS at the highest, the others were almost dead at about 2 to 10% QS. I then played with the LNB and discovered if I tilted the LNB upward with the clamp loose the signal doubled, I had noticed the factory bend in the feed arm but saw that it could only mount in one position to the reflector so I removed the feed arm and drilled a hole on the other side so I could invert it, I knew that reversing the position would provide the proper angle/tilt of the LNB. After the modification and readjusting the dish slightly I had excellent signals across the board on all TP's.

I suspect that the feed arm was bent incorrectly, somebody at the factory must have bent the tube in the die backwards. Notice the photos, this is after the modification, the red line indicates the original position of the feed arm and in photo #2 you can see the panel nut is now on the outside facing the ground. I used a longer bolt to reach through the hole I drilled and thread into the panel nut.

Does anybody have one of these dishes to compare this with and tell me what position your feed arm is in? I'm just curious and relieved that I discovered the problem and found a solution.

 

[Anole]

Is the lower support arm just installed upside down?
If not, then the backward bend in the die sounds like a good answer.

edit:
Or, how 'bout this ...
When the roofer removed the dish, he dropped it on something that bent the arm?
They're not known for being delicate.

As to why the LNB or receiver were toast, that's a good one!

 

[ghia]

edit:
Or, how 'bout this ...
When the roofer removed the dish, he dropped it on something that bent the arm?
They're not known for being delicate.

As to why the LNB or receiver were toast, that's a good one![/QUOTE]


I would agree with Anole on the bent arm / roofer theory, my Patriot dish was on the money with all the marks, focal point, etc.

Agreed why would removing the dish kill the receiver and lnb? My only thought would be Cutting the RG* cable while the reciever was powered on.

 

[McGuyver]

In regards to the above posts; I considered the possibility of the roofer bending the arm so I studied the arm closely and see a distinctive die mark, a machine stamping so to speak as if the arm was placed in a die and pressed to form the bend, the paint is not scratched or shows any signs of tampering, besides this, if the roofer had dropped it, it would have bent the side supports instead because the feed arm is lower and if it had been accidently bent, the impact would've likely been from the bottom and not from the top. There's no doubt that the bend was made at the factory in a die press, no doubt whatsoever.

As I mentioned, the panel nut is only on one side of the rectangular tube, it only permits the arm to be installed in one direction so that the end user could not possibly mistakenly install it upside down, I had to drill a hole in order to do so. I used to work for a manufacturing company where they made similar bends in tubular material in the same fashion and it would be easy for a worker to accidentally insert the item upside down in the press as there is no keyed device to prevent such an event. This is just a simple piece of rectangular tubing with a panel nut on one end which is typically installed before making bends in the tubing. A mistake of bending it in the wrong direction is very common if the worker isn't paying attention, maybe it was Monday morning, EEEK!

With the tube inverted, the LNB alignment points directly to the center of the reflector as before it was pointing below the center. The end results after the modification produced signals from a low of 58% to 81% QS vs the 0% to 32% QS on the same TP's.

As to the roofer, the coax wasn't cut but yes it was disconnected. I concluded that the roofer likely smoked both the receiver and the LNB when he disconnected it. My friend said that everything was working before he removed the dish, she didn't usually power off the stb or did she know of the danger of breaking connections with it powered on. I first discovered the dead stb when I went to her house to reinstall the dish, I didn't have any field equipment with me for testing, I assumed I could use her stb for reaiming but I found that it was dead. The roofer was not the only one who tampered with the cables either. It's a very long story but I will say that when she had DirecTV installed, they too tampered with the cables in the attic and I discovered that they used part of my FTA cabling that went down through the walls. And to top it off, my lady friend is totally clueless about anything technical, she's either the master of confusion or the end product thereof. I have to be very specific when I ask her questions, I have to first explain any details before extracting any sensible information from her so I can understand what she's saying, it's like talking to a 5 year old child, maybe worse.

So somehwere along the line, somebody or somehow the stb's power supply and the LNB were toasted at the same time. She lives 100 miles away so it's not so easy for me to drop by to check in, lots of things could happen between visits.

 

[stanleyjohn]

Just wondering how the LNB and receiver got toasted!Wouldn't want the same thing to happen here.Could it of been a Lightning strike near by? Was the dish and cable grounded properly.

 

[McGuyver]

Just wondering how the LNB and receiver got toasted!Wouldn't want the same thing to happen here.Could it of been a Lightning strike near by? Was the dish and cable grounded properly.

Good question... knowing they are both toast and the fact the roofer disconnected it with the power on, I can only contribute it to the disconnection of the coax feed. It's not uncommon for the LNB to smoke when making or breaking the coax while the stb is powered up but here they both suffered damage, maybe he brushed the end of the coax across metal and shorted the power supply after smoking the lnb. Then there's a possibility that the stb power supply toasted the LNB if it shorted out and what caused the failure is unknown so I can only suspect the roofer or the DirecTV installer. This woman has had a number of people doing misc odd jobs for her and it seems that everytime she does something gets damaged. The DirecTV installer cracked a glass shelf on a piece of her furniture and she didn't get compensated either.