As far as 900 MHz frequencies go you might be hard pushed to get one. Certainly
in Auckland there are none available. Other areas of the country you might be
lucky.

RSM will only issue mono licences in the 400 MHz STL band, or composite if the
proposed path is a difficult one. Each case is determined on an individual
basis.

Links on 2.4 GHz work - a friend of mine has built a digital link which he has
trialled over a distance of 25 km with excellent results.
As per previous posts, the units can channel hop if there is interference,
although with 4 watts EIRP there doesn't tend to be much.

Analog senders are a waste of time. They suffer from poor bandwidth due to
noise. Trust me, been down this road. Digital sender units are the only way to
go.

Licenced frequencies will always be better, because you are buying a small piece
of protection along with the frequency. Obviously your costs go up, not only for
the frequency, but for the gear to run on it. Second-hand STLs in the 400 or 900
MHz bands are hard to find.
People who have good link gear tend not to part with it as it can be re-used
elsewhere or leased out to another station.

For up to date costs on licenced services, just call your local branch of RSM -
they will have the latest figures. I avoid all that and concentrate on
engineering.



--- In LPFM_Radio@..., "Herb" <bheath.nz@...> wrote:
>
> Hi all,
>
> Just wondering whether anyone could please give me the laymans low-down on
STLs?
>
> Supposing I'm looking to move my Tx to a higher location that's, say, 5-12k's
away as the crow flies from my current studio location.
>
> I've heard stuff about modifing a 2.4GHz AV sender by putting a high gain Rx &
TX aerial (grid or otherwise) on the respective AV units. I understand these
will work over short distances, but how about over longer distances?
>
> Would it be better to buy a purpose built unit? If so, what would be an
adequate power output, where would one buy one, and roughly how much would they
cost?
>
> I notice there are some 'free' frequencies in the 2.4GHz range, but would it
also be better to get a licenced one? If so, what is the process and how much?
>
> Thanks in advance,
>
> Herb.
>