Satellite Receiver Systems.  

        There are various types of satellite signals receivable by home systems, and each has it's own requirements for reception.
Antenna.   The antenna systems used for home reception consist of a satellite dish, a feedhorn, and an LNB (low noise block downconverter). Signals can be "C-band" , which is 3.7-4.2 GHz   or one of several bands of Ku, which are all above 10 GHz.  Dishes for C band need to be big, on the order of 6' diameter to 10' or more.  Ku dishes for conventional sats are generally 3' or more.  Ku dishes for the high power DBS sats can be as small as 18".

DBS Broadcasts   DBS broadcasts are the high power "little dish" systems, ie Dish Network and DTV in the US, and the Nimiq sats in Canada. These will not be discussed here, as there is ample information from the companies selling the service.  These are KU band systems, but they are a higher frequency Ku than normal Ku satellites, ie 12.2 GHz-12.7 GHz. Also these sats are circularly polarized while conventional satellites are linear polarized.  There are a ery few channels on the DBS satellites which are not scrambled, and thus available to hobbiests.  These generally require an MPEG-II/DVB receiver to receive.

Analog TVRO   Analog TVRO is the old conventional C/Ku band systems that hobbiests have been viewing for 20 years or more.  Recently, most of the available satellite signals have been moving to digital, so there is less and less available to view on an analog only system, however a digital only system will be missing a lot of signals as well.   There are subscription channels available on analog, as well as random feeds and free broadcasts.  To receive the subscription channels, you will need a VCII+ or VCRS descrambler module.  This doesn't give you "free" TV, it only allows you to subscribe and pay for the channels.  The good points about analog are that right now, the quality on analog is better than that on any digital system, except for the HDTV systems. The disadvantage is that since it requires much more satellite space to transmit analog signals, that services are switching to digital, so it's days are numbered.  Free services found in analog format are things like PBS, NASA-TV, CSPAN and a few other channels, plus news and sports feeds.  Most cable type networks are subscription only.

DCII   DCII refers to "Digicipher" which is the digital system used for subscription services on conventional C/Ku satellites. The receiver necessary to receive these signals is a 4DTV.  Reception on 4DTVs is generally superior to DBS digital, but not quite as good as analog. 4DTV systems are primarily for subscription of cable type signals, but there are also a few "free" channels transmitted in DCII format. These can be received by the 4DTV if the 4DTV is subscribed to some pay service, and the free channels can also be received by a few rather expensive "commercial" DCII receivers, such as the DSR4200, 4400, 4500, 4800 series.  Free DCII channels include several PBS feeds, plus a few cable type networks that just send their signals in free mode.   Sometimes commercial DCII receivers can be found on Ebay.  If you are a PBS addict, it is well worth the investment, but if you are interested in other programming, a 4DTV is better, because a commercial DCII receiver cannot be subscribed to the pay channels.


MPEG-II / DVB   MPEG-II / DVB  is the newest form of home TVRO receiver.  There are no (or very few) subscription services broadcast in DVB mode, however DVB is becoming the standard mode for news feeds, foreign language channels, sports feeds, and virtually everything which isn't scrambled or subscription.  DVB receivers are also quite reasonable price wise.  A desk top model can be purchased for less than $200, and a computer card receiver can be purchased for less than $100.  
    DVB receivers can be "slaved" off other tvro systems.  Ie you can have an conventional TVRO system with a splitter so that the coax from the dish goes to both the analog/ 4DTV and the DVB receivers.  Reception of DVB signals can be quite good or it can be poor, depending on how much the uplinker is trying to compress their signal, but typically it is similar to DBS reception.   Channels available via DVB are quite variable.  They come and go, depending on the uplinker's whims.  There is typically a lot up there, but it can't be depended on. 


SYSTEM REQUIREMENTS
     For a big dish system capable of receiving C and Ku band, you will need a dish, a feedhorn, a C-band LNB and a Ku LNB, and a polarotor to change polarity.  You will also need an actuator of some kind to move your dish from one satellite to antoher, unless you are going to have a dish dedicated to one sat.  You will also need sufficient ribbon cable to go from your receiver to the dish. For big dish systems, you will want an IRD, which is an integrated receiver/descrambler/dish mover.  An IRD will move the dish from one sat to another, and will receive analog signals on either C or KU, and it has a slot for a VCII descrambler module for subscription channels. A complete C/Ku system can be rather expensive, ie a couple hundred $ for the dish , feedhorns,  lnbs, and receiver, so it can easily get up above $1000, however if you shop for used equipment, it is possible to get complete systems for $200-300, or even free if you find a neighbor replacing his system with a DBS system. 
   If you go Ku only, systems are MUCH cheaper.  the above components are about 1/4th the cost for KU, mainly because the size is smaller.