Around 1969 the first radios started making their appearance in the
field, if the dates on the various manuals should be believed. It was a
versatile family, build around two very different transceivers: the middle
range RT-3600 and the short range RT-3610 model. The RT-3610 is pretty
straightforward, although it can also be used in vehicular installations
with a adapted battery box that then takes the part of junction box.
The RT-3600 is highly modular - as most systems of that period in time
- but takes that concept one step beyond, so to speak. Where other radios
will combine closed boxes into working systems, the RT-3600 will also fit
different modules in boxes to make up those systems.
RT-3600 combined with either JB-3600 junction box or AM-3600 amplifier
This most basic vehicular configuration, a stack of two elements, can
therefore take four forms:
Now, a stack can have three elements - and as we already have the power supply, the third one would of course be another RT-3600 transceiver. This gives a two radio set-up, where both radios can be long range or short range, and either tied up into a local loudspeaker control unit or in a intercom set - that off course can again include loudspeakers. There is a separate loudspeaker LS-3621 - Amplified Loudspeaker - that ties in to any C-3621 local communications box. The C-3621 is tied into the on-board net through the IC-3620 intercom unit. Actually, this is done with a pretty neat trick: the IC-3620 has two connectors for the C-3621 intercom boxes, and they daisy chain all around, back into the second connector of the IC-3620, using CX-361x cables. The x here stands for the actual length - and there are many! This daisy chain approach gives more reliability, as one connection being broken does not put the system out of operation.
But the system is not limited to one stack: it can have two. The maximum
is a total of five elements divided over two stacks. And as each stack
needs a power supply, the second stack can have only one transceiver. All
three can be high power, low power or any mix between the two. In a full
installation you will normally find both an IC-3620 intercom unit and an
AF-3620 control- and loudspeaker unit.
Quite often the documentation discerns the various possible radio-configurations
in terms of range:
This only scratches the surface, but more information is due at a later date - my time on hobbies is limited.
12-11-2003 23:22 +0100