Kelvin Hughes Radar problem

Tarka1

Well-Known Member
Evening folks,
I've got a problem with my, almost antique, Kelvin Hughes radar in that it starts up OK but then either trips the circuit breaker or just turns off.
I've changed the breaker in case that was faulty but the problem still occurs.
Bit of a long shot but has anyone else had this problem and managed to sort it?

Thanks

Lyndon
 
Evening folks,
I've got a problem with my, almost antique, Kelvin Hughes radar in that it starts up OK but then either trips the circuit breaker or just turns off.
I've changed the breaker in case that was faulty but the problem still occurs.
Bit of a long shot but has anyone else had this problem and managed to sort it?

Hiya Lyndon.


I don't know that particular radar but it sounds like there is an electrical (RF?) flash over inside which is tripping the breaker. :confused:

Normally it can be shorted turns on a transformer or the magnetron requiring replacement but all is not lost. ;)

You need to remove the unit from its mounting and, with safety in mind, do as any electronics/RF Engineer would do and turn this beast round on the bench, and with the power disconnected for at least the previous hour or so (preferably overnight) to make sure all circuitry inside is discharged, remove all covers and see if you can see any charring or places showing flash-over?

If not, you are going to have to turn it on with fingers well clear and no children present. You are looking for smoke, you are sniffing for any burning smells and you are listening for any crackling sounds.

You have to sit patiently and wait for the unit to trip out and note what you heard and from which part of the radar unit the noise emanated.

Only when you have done this will you have an idea as to what might be wrong. If you find any faulty area or circuit, switch off and disconnect from supply volts BUT DO NOT TOUCH ANYTHING INSIDE as it might/will be carrying a few hundred volts. Leave over night as before and afterwards, take photographs of any faulty unit(s).

Report back. :)
 
Evening folks,
I've got a problem with my, almost antique, Kelvin Hughes radar in that it starts up OK but then either trips the circuit breaker or just turns off.
I've changed the breaker in case that was faulty but the problem still occurs.
Bit of a long shot but has anyone else had this problem and managed to sort it?

Thanks

Lyndon

we had a kh type 17 with a motor alternator. The supply batt had to be able to deliver at a good voltage, or it would trip.

Take cover off trancever box, release the interlock plunger on the right, select gen voltage on the rotary switch & turn on.wait and watch, report back.

(frightening, I can see it so clearly, but last saw it in 1989!!)
 
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Mmmm, low voltage causing it to trip??
Now you've got me thinking...
The power supply cable to the unit was getting very hot around one of the connections, I thought I'd sorted it but maybe I'll need to take a 2nd look at that.
From memory there is a 3amp(?) fuse on the display that protects the cable off to the radome and that has never blown so I was thinking it was a problem with the CRT display
 
K-H Radar problem

Is this a Kingfisher?
When you say it starts OK then trips, does it actually run correctly - for how long?
You can power on the display with the radome unplugged to see if the problem can be localised to one unit or the other.
Which cable is getting hot? If it's the power cable, is it hot for the full length or just locally? If it's just locally, cut it and re make the end, as it may have crumbled the insulation inside and further heating will make it worse.(or a poor joint in a plug or socket)
There was someone on here who lived with these professionally in a previous life, but his hints were mostly directed at radome faults, which may not be your problem.
I never found the K-H truly satisfactory in comparison with similar vintage Furuno sets, but I guess replacements nowadays are all going to be digital flatscreens like the Garmin, not cheap, but at least the cables stay cool.
I assume you have the book -I have it scanned if you need it.(PM)
 
are you certain on running radar bits unplugged, as i was told if the pulse lock was unplugged it fried the timebase board, again on the kh 17.
 
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