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Lynn Coffelt

"Bruce in Alaska" wrote in message
...
In article om,
wrote:

Hello there,

I got 3 furuno display units models 2400& 1600 ,their yellow/green
CRT shows a freezed straight line when powered on 13V; having this
line turning 360 ° all the time is a simple matter of feeding the
proper signals to a stepper motor that controls the rotation of the
yoke around the neck of their CRT.

Can I do that without the antenna units & simple internal mods ?

If I could have them work the way I want, my daughter will have fun
with the scopes, as she wants to be a space controller; then she will
"see" the invaders coming ;- )

Thank you & happy new year to all.

Patrick

Not without suppling a Bearing Input signal to the Main Connector.
The Bearing Input is nothing more than a Pulse Train generated up
in the antenna, by an LED/PhotoDiode Pair with a ChopperWheel in
between. A simple replacment would be a NE555 running at 1800Hz
and fed into the Bearing Input connection.

Bruce in alaska

Seems like our homebrew shop antenna simulator also used a headflash switch
simulator to keep the bearing motor from halting at brg 000 each revolution?
Or maybe the switch simulator was only necessary to synch the actual antenna
with the indicator bearing motor? Hey, it wasn't yesterday!
Old Chief Lynn