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

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
--
add a 2 before @

"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

Hi 2 all

Thanx for the feedback !

Will try that with a function generator until moving this line on the
scope...

Thanx again &happy new year to all.

Patrick

In article ,
"Lynn Coffelt" wrote:


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



Seems to me, as I recall, you only need the Heading Pulse to resync the
system. As I recall, the AutoSync didn't come out untill after the 2400.
I built my own simulator, and it generated both Heading Pulse and Bearing
Pulse Train, by counting the Bearing Pulses, and then adding a Heading
Pulse at the approprate time. Had to design it for a cople of different
Pulse Trains, for different units, as I recall. Been a LONG TIME, since
I even looked at that stuff. I wonder if I can even find my old
simulator now........ Hmmmm Alzhimers maybe setting in....

Bruce in alaska
--
add a 2 before @

Hi Bruce,

"Forget" about alzheimer ;- ) you was right
I have fed a #2400 model with pulse signals on J59 connector (black,
grey & violet) @200Khz/200mS; worked well ...

Thanx again.

Patrick