In article 2005072120424116807%lost@nowhereorg,
John Proctor wrote:

Group,

I've started back into marine electronics fitting and repair again. We
have an older scanner MRT-136) that is part of an MD-3600 radar system.
The radome got wet (yes Larry other manufacturers do get wet from time
to time). The owner want's us to have a look at it but the local Koden
distributor doesn't have any manuals going that far back. Does anyone
have a service manual or know of where I can find one for the scanner?

If you have some experience with small commercial xband marine radars
you shouldn't need a manual to figure out what quit in the T/R Pan on a
Koden Radar. They are very similar in design to the JRC, as well as the
Furuno's of the same period. Take a scope and look for the TRansmitter
Trigger Pulses coming up the line from the display, and follow them thru
to the Modulator Switcher, and then check the RF output of the Magnitron
with an NE2 neon bulb. For receive, just see if you have noise comming
down the video coax from the IF amp, and monitor, either the Crystal
Current, or if this has a LNB, put your scope on the output of the LNB
and look for pulses and grass in between the pulses. Most of the old
hands have an Xband RF Test Box that can simulate Xband RF Target
Returns, to the antenna port, as well as minitor the RF output from the
cirulator. Having the right test equipment is essential in working in
the Marine Electronics Field.....



Bruce in alaska
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