Satellite channels are transmitted either "free-to-air" or are encrypted. In general, a free-to-air channel can be picked up by any receiver of the right general type (e.g. any analogue free-to-air channel can be picked by any analogue receiver), whereas an encrypted signal needs a receiver of the right kind, i.e. containing the corresponding decryption circuitry. In fact, almost all encrypted signals also require the use of a ciorresponding smartcard, provided for a subscription fee by the broadcaster. Some broadcasters package the card and receiver, typically providing a rented receiver included in the monthly subscription fee. Even broadcasters using the same basic enmcryption format will still typically issue separate cards - cards which grant access to just their particular channels.
JSTV is one of the channels which encrypts the signal, so that only paying subscribers can access it.
It is currently simultaneously transmitting on 2 satellites, using 2 different systems.
The one you have come across is on the Hotbird satellite. It is a digital transmission, encrypted under the "Cryptoworks" system. That is just one of many different digital encryption systems that are currently used.
The second one is an analogue tranmission at Astra-1, encrypted under the Videocrypt system (note: this is the same satellite and system used by the Sky analogue services - although a Sky analogue card will not give access tro JSTV).
So you have two choices.
You can buy/rent a digital receiver with in-built Cryptoworks decoder or so-called "CI-CAM" (loose, insertable decryption module) and then point your satellite dish at Hotbird. Or you can buy/rent an analogue videocrypt receiver and point your dish at Astra-1.
In both cases you will need a suitably activated card from JSTV, and it is possible that they have a subscription package which includes equipment. In any event, presumably when you contact JSTV they will offer and explain the various options to you.
As for Sky: it is no longer possible to get a Sky analogue subscription (they are shutting the service down completely July/2001) so one is forced now as a new subscriber to go for Digital.
Check out the Sky forum on this board for more salient points. The most important things you need to be aware of are
- Sky Digital subscriptions are only available to UK/ROI residents
- the necessary receiving/decryption equipment is proprietary (only available from Sky), and no other receiving equipment is capable of picking up Sky digital. IE whether you go for the Hotbird/Cryptoworks or Astra1/Videocrypt version of JSTV, you will still need a separate dedicated box for Sky Digital.
- the satellite they broadcast from is neither of the two that JSTV broadcasts from (Sky-Digital is on Astra-2 - so you would need a separate dish pointing at that satellite too).
Hope this helps. Welcome to the wonderful world of satellite!