Can you put a round dish on a Slimline mast?

That’s the question one of our customers asked recently. It ended up being quite the source of discussion around the Solid Signal Blog conference table, and to me that means it is also probably a good topic for an article.

So let’s get this out of the way.

No, you can’t.

The Slimline J-mount, and all other mounts designed for the DIRECTV Slimline dish, has an outer diameter of 2 inches. In other words, that’s the measurement of the outside of the mast. In order to connect a regular round dish, you need a mount with an outer diameter of 1.66 inches. So, the smaller dish won’t fit on that mast. Instead, get this J-mount, which works great.

When measuring any sort of pipe, it’s important to note if you’re talking about outer diameter or inner diameter. Inner diameter is important if you’re talking about something flowing through, while outer diameter is important if you’re connecting something to another thing.

Why are all these things different sizes?

The Slimline dish is larger and heavier than a regular 18″ dish. That’s pretty obvious. When it was first introduced, DIRECTV engineers had noticed other large dishes swaying in the wind, causing problems with reception. Using a stronger mount with a larger point of attachment makes it possible to secure the dish down.

Now, it’s possible that the folks at DIRECTV were a little too conservative here. DISH uses a 1.66″ outer diameter mast for its HD dishes and it seems to work pretty well for them. Granted, the original DIRECTV Slimlines pointed at five locations while DISH antennas only ever pointed at three. However DIRECTV dishes now point only to the three primary locations of 99, 101 and 103 so they are probably not as prone to issues with wind as they used to be.

Will AT&T make a change?

The thing is at this point it could be quite possible to have a smaller dish on a smaller mast because the three satellite locations are quite close. The Slimline dish is as wide as it is because it originally needed to get signals from two sources 20 degrees apart. Since all three active satellites are only 4 degrees apart it’s possible that a much smaller dish would work. Such a dish could easily work with a 1.66″ outer diameter mount But… it’s probably not gonna happen.

In order to do this, AT&T would have to engineer a new dish. And you’d have to ask yourself what the benefit would be. The new dish would be cheaper to make but how long would it take to make up the engineering costs? The current dish meets all HOA regulations and it’s not like there would be some sort of incentive to make it smaller. It’s not likely that there would ever be a dish small enough that it really would make a difference in people’s perceptions.

So, even though the Slimline dish is pretty overbuilt for today’s needs, it’s likely to stay that way. In the meantime, the round dish is less and less common these days anyway so the Slimline dish with its oval shape has become a bit of a brand identifier for AT&T. That’s not a bad thing either.

Oh by the way…

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About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.