Difference between reflectors?

[Robert Hume]

I have a SWM Slimline, about 5 years old or so. I live near the ocean so it's subject to corrosion and discoloring. My HOA said I needed to replace my dish because it looked bad - and I know better than to argue with Nazis.

So anyway I recently purchased/installed a new reflector which was exactly the same dimensions as the old one. However, it doesn't say "Slimline" on it, the color is a darker grey, and the DirecTV logo is white instead of black. Otherwise, the reflectors are identical.

I was surprised to find that after installing the new reflector (I was careful about not adjusting the reflector mount orientation), I got a 771 error. I still received on the 101 but did not get 99 or 103.

As a test, I placed the old reflector over the new one, and my signals all came back. I repeated this process 5 times. The new reflector simply does not work. Now, I've purchased an exact Slimline replacement (unused, but not mint condition) which I guess I'll have to use instead.

QUESTION: What is the difference between the two reflectors? Is it coating? Paint color? Is the focal point different but small enough to avoid observation? It seems illogical that two dishes with exactly the same shape do not present the same results.

Thanks in advance for any insight into this weirdness.

 

[AZ.]

I will assume there is no difference in the dish.....Its the LNBs and the mast that holds them.....I bet your focused at different satillite because of he arm?

 

[Robert Hume]

I appreciate the response AZ.

I used an identical arm (same length, same size - it bolted into the same holes) again except for the color, and I reused the existing LNB. I bought the reflector, arm and mounting bracket and bolts. Not wanting to alter the orientation, I only replaced the reflector itself and the arm, both of which are the exact same dimensions as those they replaced. I didn't change or move the mount.

UPDATE: Because of your comments, I just went outside and inspected very very closely, and while the arms are indeed identical, I believe I may have found a slight difference between the reflectors. The original one describes a slightly more narrow parabolic shape, as follows.

When the original is placed over the new one and pressed flush on one side, the other side is about 1/2 raised above the surface. This would theoretically change the off-axis angles of reflection and therefore the focal point just enough to where the 101 comes in but the HD ones (99 and 103) do not. I'd imagine this is the issue; the replacement I bought was not a SWM reflector. Although it was advertised as such, I doubt the seller is much of an electrical engineer.

So it appears the mystery is solved and I'll chalk up another lesson in capitalism.

 

[texasbrit]

Yes, it is probably not a slimline dish (nothing to do with SWM, that's the LNB)

 

[Zashel]

View attachment 109688

mmm, nope. they're the same.

 

[waylew]

So why not just repaint the old one ?

 

[Robert Hume]

Hutch: they're not exactly the same, as described in my post above. Slightly different shape along the z-axis.

Waylew: there's unfortunately only one answer to your question: because I was ignorant and had more money than brains.

I just now finished doing 5 minutes of research on the question that FINALLY popped into my head this morning: Why not just repaint the old one? So I came up with the instructions below for anyone else who may be interested.

Repainting your weathered reflector
----------------------------------------------

1. Remove the reflector mounting bolts and unmount the reflector; do not
change its orientation.

2. Remove surface corrosion. Try using 400-grit sandpaper; wipe clean.

3. Repaint reflector: use a thin coat of matte grey primer/sealer; then use
neutral or darker colors - no metallic (like gold or chrome) or bright
white, which could reflect too much heat from sun into the LNB and cause
damage to the electronics.

4. Finish with Rustoleum Painters Touch 2X Ultracover Matte Clear. Do not
use a gloss clearcoat, which like white will create a gloss surface which
will reflect too much heat into the LNB.

Hope this helps, RH

 

[Zashel]

Hutch: they're not exactly the same, as described in my post above. Slightly different shape along the z-axis.

you have one of two things going on here good sir:

1) you have a reflector that was bent in shipping (unlikely, but not impossible)

2) ever stack chairs? the legs on the 2nd chair dont reach the ground. by pinching the one side you're making the mounting holes push the opposite side higher (since they are recessed for the reflector side) so the two sides will never sit flush.

 

[Claude Greiner]

Why not just replace the entire dish assembly.

There are like 2 different slimline dishes out there because in my shop I got a pile of mis fitted parts.

 

[doctor J]

Just wondering if the original poster got a World Direct dish and thought it was a slimline??
Doctor j

 

[schneid]

Repaint is the answer I like.

 

[peds48]

Just wondering if the original poster got a World Direct dish and thought it was a slimline??
Doctor j

No, there is a new dish design come out (being tested on some areas). Supposedly less pieces to put together.

 

[Zashel]

a different one than the one i linked to in post #5? because that one is the same #.

 

[peds48]

a different one than the one i linked to in post #5? because that one is the same #.

That seems to be the new one as it has no bolts on the side of the LNB arm.