Roof Interference?

[rogerduncan100]

Greetings all.

It's been a while since I have lurked around here.

Is there such a thing as roof interference from asphalt shingles? I think I have done everything possible to make my K-band motorized dish setup as perfect as it can be, save buying new equipment but I still can't lock in 30W Hispasat or anything east of 83W AMC9. The only exception is signals from 72W AMC6 (NBC mux, etc.) which are coming through the neighbour's tree!

I have a theory of roof interference because 30W Hispasat is almost straight across the roof from front to back of the house. I have attached two pictures. Also,
could the HD antenna be the culprit? It's in the line of sight but I turn it so it faces perpendicular to that line which makes it as skinny as it can be.

Thanks, everyone.

 

[Magic Static]

Is the weight of the LNBF twisting the skew off? Replace it with one of those small high performance ones.

 

[Pixl]

Roger,

It's not likely you have reflections off the asphalt shingles that would amount to much. If you are sure you have LOS at 20deg for Toronto you should get this sat. (recently replaced with strong TP's) Probably more to do with dish alignment.

We are discussing problems with motorized dished at the ends of the arc right now in this thread.
http://www.satelliteguys.us/free-ai...ntic-satellites-0-61-degrees.html#post2552216

Check out SatAV's post.

 

[Mikey11]

sounds like an alignment problem to me....when you use USALS is your motor going to other satellite positions properly?....you say you get 83w....when you use USALS does the motor lock onto 83w with good quality?....if not this could mean your motor is not aimed properly....

also are you sure your motor is mounted 100% level?....do not assume the motor is level just because the pole is....put a small level across the top of the motors bracket in 3-4 different ways....it should read level everytime....if not you need to adjust your mounting pole to make it level....remember its not the pole that needs to be level....it is the motor bracket that needs to be level....

a motor bracket that is not level or a motor that is not aimed properly will give problems toward the ends of the arc moreso than near the top of the arc....and 30w would be close to the end of your arc....if i had to place a bet here i would say you need to work on your alignment more....

 

[rogerduncan100]

Mikey


Thanks for your thoughts. I have been at this for a long time I can assure you! Later I will add more to this thread when I can think better. Just came off a 4-day jury deliberation in Toronto regarding a mother who made her adopted daughter available to a pedophile. Yuk.

 

[rogerduncan100]

FineLeveandTiltAdjusmentPicture



This picture shows pretty well my additions that allow fine adjusment of level and tilt.

I still can't get anything east of true south other than the NBC mux satellite. PBS at 125W booms in fine as do all the others over to Tuff TV at 83W.

Maybe I need to try more but I wonder about roof interference or blocking from the OTA antenna.

I dunno.

 

[rogerduncan100]

Also, in response to your question, USALS works great for me. I don't have to tweak the motor even one step.

 

[SatelliteAV]

Without any reference to true South in these photos, I would suggest that the majority of the eastern arc is behind the neighbor's tree. I would guess that at least 30+ degrees of your arc is behind that tree. You should be able to easily see 30W as it is only approx. 58 degrees east of true South. It would be very helpful to help diagnose the line of sight issue if you could post two photos taken from directly behind the dish shot level (with the horizon and the sky for reference). The 1st photo when the dish is aimed at 79W and another when the dish is aimed at 30W.

Since 72W satellite is only a few degrees east of your true South satellite, the motor and dish may not be installed correctly to track both sides of the arc. It is very possible that you have the settings adjusted so one side of the arc is tracking perfect and have no arc tracking on the other side. If you never set up both sides of the arc during the installation, then I believe that the east side your arc is off. How can this happen? By setting the Motor Angle incorrectly then compensating with the post mounting and the dish angle.

I attached a PDF from www.GeoSatFinder that is useful in determining LOS issues.

 

[Anole]

elephant in the room

I'm kind of also curious about that stack of washers between the motor bracket and the clamps on your pole.

 

[rogerduncan100]

The washers are spacers. The additions allow me to adjust to make sure the motor is level. The wood and screw allow fine adjustment of elevation angle.

 

[comfrey]

Love the idea for fine adjustment, I may just use that if/when my 1.2m dish needs fine-tuning.

 

[rogerduncan100]

I definitely have line of sight to 30W. 72W is behind the tree and 83W is just at the right edge of the tree.

I certainly hope I can still get the full arc instead of just half of it. With my added fine adjustments it should be easier.

 

[hd fan]

Did you double check the dish settings for 30W? Maybe there is something there causing the problem. Looks like either alignment or settings issue. BTW you might have an issue in the hot summer days with the horizontal polarity TP's on 30W since the asphalt shingles are going to release lots of heat right in the path to 30W. I face the same issue with a ground installed Dish to 30W , it only affects H side, and only a few days in some rather extreme hot summers.

 

[Mikey11]

I definitely have line of sight to 30W.

if you want to make sure you should loosen your motor and just aim the dish/motor at 30w manually, temporarily....basically use 30w as your true south satellite....this will at least tell you the line of sight is clear from your mounting location....

 

[Pixl]

The washers are spacers. The additions allow me to adjust to make sure the motor is level. The wood and screw allow fine adjustment of elevation angle.

Roger,

Shimming the motor with washers is an interesting approach, but I wonder if you are still off. From looking at the photo I can see how you could correct for N-S if the pole is off. But what about E-W ?
The best policy is to start with a post that is absolutely perfectly level in all planes, then you wouldn't need washers.

Perhaps you could correct this correct this with a combination of re-positioning and shimming the wall mount.

 

[Mikey11]

Roger,

Shimming the motor with washers is an interesting approach, but I wonder if you are still off. From looking at the photo I can see how you could correct for N-S if the pole is off. But what about E-W ?
The best policy is to start with a post that is absolutely perfectly level in all planes, then you wouldn't need washers.

Perhaps you could correct this correct this with a combination of re-positioning and shimming the wall mount.

this is good advice but what i always stress is....it is the MOTOR that needs to be level, not the post....and just because the post is level that does not guarantee the motor will be....

so what i do is mount the post level and sturdy and strong....then install the dish/motor assembly and aim at southern most satellite using USALS first....once the motor is aimed and bolted tight, i put a level accross the motor bracket in 4-5 different ways....if the motor bracket is not 100% level then i adjust the mounting post until it is level....

 

[rogerduncan100]

Thanks for your input, guys!

There is a history to my madness which is: I mangled the motor mount so badly with countinual tightening and re-tightening that it no longer mounts the motor level even though the pole is plum. This setup allows me to level the motor anyway.

I have checked motor angle (90 degrees minus latitude) and it's perfect.

I'm out of time right now but I do have something I am going to try when I can and I will report back on this thread.

I am glad to hear that I can probably get 30W if I keep trying!

Cheers!