Whether you work with commercial equipment like this SWM-30 multiswitch or just average DIRECTV equipment, you need to know what to expect when setting up your system. You’ll need a signal meter like our AIM Advanced Installation Meter to test, because signal levels are measured in dBm at the frequencies used by DIRECTV satellite systems. That’s not something you’ll be able to figure out with the sort of meters you’ll find at your local department store. It’s not even something you’d find with equipment from most tech web sites.
A little bit about measurement in general
Remember that on satellite systems, dB numbers are negative, measuring from -1 to -100 (typically.) So numbers like -50 are very low and numbers like -20 are high. That’s hard to get used to, but eventually it makes sense. dBs are also logarithmic, meaning that a loss of 3dB means a 50% cut in signal and a loss of 10dB means a 90% cut in signal.
How much signal should come from the dish
Power levels at the dish can vary wildly depending on your location. However, the LNB itself does normalize the signal somewhat. If this is an installation with a separate multiswitch, you are generally ok using the built-in amplifiers on the SWM but if you measure less than -45dBM (in other words like -60) at the input point of the multiswitch you may want to consider the use of an commercial amplifier like AT&T’s STA series. This amplifier takes in signals up to -45dBm and puts out a stabilized signal that you can set to -10 to 0 dBm. 0dBm is too strong for most receivers, so you should be prepared with attenuators if you use this amplifier.
Whether it’s a simple SWM-enabled dish or a fancy multiswitch, look for signals to be around -25 to -28dBm at the exit of the multiswitch. If the number is higher (like -21) that indicates a problem with the internal amplification and could be due to faulty equipment. If you are using an adjustable external amplifier you may choose to turn down the level.
As the signal travels down the cable it loses strength. There are several great signal loss calculators out there. (This one at net-comber.com works well without a lot of extra clutter.) If you reach the point where the signal is -45dBm or less (in other words like -60) at the receiver you will begin to have whole-home problems. If it’s below -60dBm you’ll probably have problems with video and audio dropping out.
What if you need more signal than that?
That’s where it gets a little complicated. You can add additional STA amplifiers before the SWM, but once you get on the other side of that SWM, amplifiers don’t work. I explain why in this article. So the best thing to do is to make sure the SWM multiswitches are where you need them to be. There is, of course, the high-powered SWM30HP. It outputs a very strong signal that can go up to 400 feet. Problem is, it’s such a dangerous piece of gear we only sell it over the phone. It’s guaranteed to blow up your receivers if you hook it up wrong. Better for average folks to just forget it exists.
Working with a satellite meter, it should be possible to figure out where the problems lie. Then you can address them so your whole system works as expected. You can plan everything out and put SWM multiswitches where they need to be. In extreme cases, you may want to use a second dish to go where you need. It’s always an option.
Of course no matter what you need for your dream DIRECTV setup, you’ll find it when you shop at Solid Signal.