Globecast antennas

[AntAltMike]

Does anyone have any idea why Globecast furnishes those screwy, oblong antennas that are needlessly difficult to aim? Might they be contemplating acquiring additional transponders on a nearby satellite and want the customer base to already have reflectors that can readily be fitted with a multiple LNB feedhorn assembly?

I fought with one such dish last night for an hour in the Washington, DC area but couldn't develop a signal quality of better than the mid 50s. I called Globecast and their telephone technician thought I should have been able to get the signal quality up to the 70% -80% range. Anyone from this area have any signal quality figures to compare that to?

[bryan27]

Mike, looks like the old primestar dishes don't they :)

The KU Band dishes are a bit more difficult to install because they have to be exact (a movement of a centimeter and signal is gone). DBS dishes can be way off and still have a signal lock.

The round dishes they used to send were much better. I get a signal of 82-89% on their old round dish. On the slightly smaller oval I get 76-79%.

It took me all day to get my round dish set up. Why? Because the elevation on the dish was off by 3 degrees, I kept hitting other sats!

Why use a smaller oval dish? They compete directly with E* for international customers who probably want a smaller dish.

[PSB]

I done a Globecast service call yesterday, and got a signal of about 75 here in St Paul, the last one I done was about 80. I know what you mean about the dish! But at least its solid, not like most of the cheapo dish you get for FTA satellite. The worst one I have came across yet is the dish they are using for home school channels on T5. its like a huge frying pan with a rim, when you attach the support arms (from rims of dish to each side of LNB) it pulls the dish out of focus, so I had to drill my own holes in the rim of the dish to keep the shape!

[TV Tommy]

Hello All,

I'm new to the Forum... and hopefull can shed some helpful tips on antennas and DBS.

Globecast:

Q: Why do they use that big (eliptical) dish? (you'll be surprised!)

A: Believe it or not (but I've verified), They've chosen the Channel Master (now Andrew) Gainmaster 75E antenna for the following reasons:
--- Rigid... holds up over time... so performance is consistant
--- Since you're dealing with FSS V/H polarization, you need to skew your LNB (correctly polorize)... since few of you have the tools to do that, and techs will inadvertantly screw up +10 with -10 degrees (whoa 20 deg off!), they made it easy... skew the WHOLE ANTENNA (yup, that's true!).
--- If you notice the interesting LNB head they use, you'll notice it is also somewhat elliptical, allowing the antenna to sway back and forth a bit, and still receive signals.

The Globecast techs told me that they played with quite a number of antenna and LNB combos and the 75E was really the strongest, and simplest overall. As for expected quality? Here in Wisconsin, we have 78-85, and that's ALWAYS with the receiver on a short cable as close to the antenna as possible.... we've tried various LNB's and receivers, and the variation is in that range, when fed off the same antenna.

We've found that life is pretty simple, if you follow a few rules:

1) If you can test for signals ON THE GROUND (we use a tripod) FIRST, you're SMART!

2) If you set that mast up EXACTLY PERPENDICULAR (STRAIGHT up and down) Youre REALLY SMART!

3) SET YOUR SKEW and ELEVATION BEFORE you put the beast on the mast. It's a better suggestion than you might think.... but we've found that the lock-down spot is usually within 1 degree (oh sure they're touchy). Fine tune as needed.

4) Have a compass, move through AZ slowly.... fine tuning AZ and EL WILL get you that 75+ number.


We're building out some Gainmasters with 97, 101, 110, 119... with a focul center of 104 degrees... Wouldn't you know DirecTV threw a wrench in it by launching FSS at 95... guess I'll need one of those funky feed assemblies from a SuperDish 119/121 for 95/97 or similar

Best of luck and skill to you all!

Tom Friedel

TV Tommy (purveyer of antennas for over 30 years!)

[PSB]

Thanks Tommy!

I have had NO PROBLEM pointing these dish with my positive identification satellite meter, set the correct elevation and skew swing the dish round "BEEP BEEP BEEP" peak the signal and you are done!
It takes all the skill out of it but in the middle of winter I just want the dish part of the install done (correctly) as soon as I can!
Not the best dish in the world but far from the worst!
All the best!

[kenglish]

They are a commercial quality dish. The most important thing to do is, be sure the mast is plumb, then make sure you set the polarization/skew exactly as it should be for your location.....this is what keeps adjacent satellites and the adjacent transponders (on the same sat) from interfering. If it is wrong, many transponders will be good, but a few will be very bad....you'll get good signal strength readings but bad "Q" readings and bad pictures.