Dish size and polarity

[markbone100]

Been wondering on this one for a while now. Been reading the minimum size for a Ku dish is 36", which 30 will work also. Bot for the ellipical dishes that are for example 35Lx26H, would that dish be only useful for horizontal signals since the vertical is too small (under 30 inches)? I have had some offers for free dishes but they are the directv ones that to me would be too small to use. I would like a dedicated dish for 97W, 101W, 125W, and maybe one for 87W or 89W for the feeds on those two. Really hate to go through all the effort to put in a dish then find its too small to use

 

[Mr Tony]

it will work fine. If I remember right, elliptical dishes help reject adjacent interference from the other satellites

35x26 should be fine. What I've remembered is you split the difference between the two and it works "like" that size dish...35x26 would be around a 30 1/2" dish
I used a 37x27 dish with no issues (until the built in LNB blowed up)

I know folks have had issues with Superdishes which are 36x20 with weaker transponders

 

[Anole]

I'm with Iceberg on this, but...

If you're feeling nervous, why not put a temporary pole out back?
I keep a 5 gallon bucket of cement with a pole in it for such tasks.
Mount your desired dish. Aim and check signals.
Monitor for a few days (or through the rain).
If you're happy, move the dish to a proper mounting location (yes, that very dish).
Start over with the next dish and bird. - :up

If you find some transponders don't work well on your smaller dish, try a bigger one.
That way, you can deploy smaller dishes (if you have 'em) for the stronger birds.

 

[markbone100]

Sweet! I didnt know elliptical dishes worked like that. Now I just need to scout around and try to find some decent sized ones.

 

[Anole]

If you use elliptical dishes, keep the original feedhorn (and maybe LNB).
That way you see the entire dish.

Here's a little table of some common dish sizes to look for or to stay away from:

Primestar / ChannelMaster dish info:
size, width x height
1.2m = 48x52 round
1.0m = 40x43 round
84e is 40x30
75e is 37x27 arm: 21"
70e ?? 35x21 Hughes (special)
60e is 32x20

DishNetwork Superdish and DirecTV dishes:

DishNet SuperDish: 36" x 20" h
DishNet D-500:... 20.5 x 22" h
DirecTV Slimline: 32.5 x 22.5 h
DirecTV Phase III 20.5 x 18.5 h

 

[markbone100]

Out of that list, what ones should I stay away from

 

[Anole]

general guidelines

I wouldn't recommend the 70e nor the 60e.
Not to say you couldn't get some stronger signals on 'em.

All the ones listed under DishNet & DirecTV would be my last choice to play with.
The D-500 and the Phase III are just too small, regardless of some members here (even me) experimenting with them for fun.
I wouldn't spend a lot of time with the SuperDish or Slimline, 'cause there are no feedhorns that will make maximum use of their area.
Yes, here on the forum, some members have put regular after-market LNBFs on both and bragged about their success, but as I see it, there's a fine line between good and getting by.

In the end, bigger is better, clear days are better than rainy ones, and a bird in the hand....

These answers are seat-of-the-pants, and personal opinion.
Best if you experiment, if you don't want to take the good advice and go with 36" dishes.
Transponder power and satellite footprint vary from one to the next, and across north America.
Some S2 signals with poor FEC will require the top-of-the-line for reliable reception, so keep that in mind as well.

 

[guacharaca]

Both for the ellipical dishes that are for example 35Lx26H, would that dish be only useful for horizontal signals since the vertical is too small (under 30 inches)?

Horizontal and Vertical signals are equal as there is a hoizantal and vertical component of the whole surface area of the dish that can be reflected into the lnb. Think of a Horizontal and a Vertical signal for each square inch of the dish in order to more easily understand why they are equal.

 

[Panavision]

Polarization refers to the E plane, or electric field as in the term: electromagnetic. A wave can be said to be polarized horizontally, but there's a magnetic field (H plane) that's just as important that's perpendicular to the E plane.