mortond wrote:
I am using a Mac Powerbook 15" running MacENC charting software using free
BBS government charts,
I have a GPS antenna connected to a USB port.
I am told I can connect a Radar radome to a serial Miniplex lite and
thence to a USB port on the Mac.
The output, from the radome has to include:

$RARSD Radar
$RATLL Radar target
$RATTM Radar tracked target

Does anyone know which manufacturer's radome would have the required plug
and outputs.

The outputs you describe do not come from radar radomes but from the
NMEA output of a radar display, e.g. something that processes the analog
data from a radome and combines it with GPS data into a target position.
So you need a full radar setup, not just the radome.

Radar "black box" systems w/o display do exist, but are not cheap. Koden
makes most of them (Sitex, Nobeltec).

The idea is that if you select a target on the radar using a "cursor" on
-screen that you can see which geographical position this is on the
chart display (MacENC). With recreational radars there is no ARPA, only
MARPA, so you have to point out the targets to the radar first, after
which it will track them. Only the higher-end radars offer MARPA, low
end radars only allow you to select a single target without tracking;
still useful.

So to put it into perspective, what you will NOT get is full radar/chart
overlay -- the radars don't put out this data _and_ MacENC cannot
receive it. There are only a few PC solutions that handle this, and none
of them exist for the Mac AFAIK.

It all sounds too good to be true to be able to combine all this info. on
one screen. Apparently AIS can also be displayed using this same setup.

Yes, AIS can be displayed as well. In fact, AIS is more useful to show
on the computer since it displays so much more data, and targets
automatically show up (no action involved). An AIS receiver is also a
lot cheaper than a radar radome + display, and easier to install. Still,
AIS does not help for (a) low visibility (b) small ships that don't
carry AIS transmitters.

My suggestion, given your current setup, is to get an AIS receiver and a
Miniplex Lite.

Hope this helps,

Kees