1715 no bearing pulse error

[SVCirrus]

I have just bought a sail boat. the prior owner told me the radar works, however unit has the error message "no bearing pulse". I have tried the diagnostics and set up and received an NG.

the unit is attached to Furuno GPS and works as a repeater in this capacity.

I believe the rotor is turning. The cable was split and has a coupling bar, which is mounted inside a metal box. It appears that the unit was professionally installed at the time of original installation. I tried cutting back the coaxial cable inside the bundle and worked on this connection. I also cleaned the outer shield cable. the larger colored wires do not have any obvious corrosion.

the display appears to show a sweep but the return on the display only shows a tight cluster of Noise.

I wonder if there is anything further I should do before I either hire a professional, or reutrn the unit for service. I have a delivery run up the coast of southern New England USA in two weeks, Radar woudl be helpful

thanks

 

[Johnny Electron]

I am confused about your comments about this being a repeater. The 1715 can't be a radar repeater or share the radar with any other unit. The error seems to indicate the motor isn't turning. If it is turning, it sounds like your scanner cable is damaged and the BP pulse isn't getting through to the display. I would ohm out the cable wiring. If you can't find the problem; a dealer would need to look at it.

 

[SVCirrus]

No it repeats the GPS data from a NEMA connected Furuno GPS ( late model not a ploter )

 

[SVCirrus]

which wire carries the BP signal? ( color )
Do you know what an acceptable Ohm value for this circuit is?

 

[Johnny Electron]

Page S-1 shows it to as yellow. (with no power applied) The cable should be a direct short between where it connects to the back of the display and the 9 pin connector in the scanner.

 

[SVCirrus]

so a single wire, not a loop? to test must check conductance at radome to the pin on the display?

that's a long mulit-meter wire from mid mast to display at nav station. Sounds like I have to take the unit off the boat to check? Is that correct?

 

[SVCirrus]

the problem is that the cable is routed through the mast... sigh

 

[Johnny Electron]

(With no power and cable removed)
Normally when ohm'ing a long wire, you use another wire to help. For example you take a paperclip and connect the overall cable shied wire to the wire you are testing (at one end of the cable) then at the other end you ohm between the cable shield and your test wire. If it checks good, then the wire isn't broken.