JRC Radar problem-need help

[massey1010]

My Radar model 1000 has given me 484 hours of reliable service but now it has become unresponsive. I have observed the following: The screen lights up, the screen responds when I turn up the sensitivity, the GPS indicators on screen work while connected to my GPS, The wires are all good-have checked with an ohmmeter, the antenna turns, fuses are fine feeds and grounds are ok. Could it be the Magnetron? If so where can I purchase one and how much do they cost? I have the manuals with the basic wiring diagram but no diagram for the circuit board.

[unclemack]

I've got a Mk.II but it's just a spare and it's buried in a locker atm.

Had to replace the scanner connector on the display - both the 10-pin chassis plug and the cable socket. Also had to rework some cracked tracks on the display board nearby. Suspected it would be a common failure because of cable flexing.

Before I found the problem the scanner rotated, screen showed "no signal" or similar after warm-up, first thought was magnetron.

Was a few years back & annoyingly can't remember the make/model of those plugs/sockets but can check back if you need it. They were available but I had to look hard.

I've very limited radar experience because of regulations & safety but don't magnetrons usually fail slowly? Don't know typical life either, sorry.

I'll see if there's a schematic in the manual I found way back then, memory's useless nowadays

[unclemack]

Sorry, manual must be on old pooter that's in storage somewhere.

Found this though from member JRC Support to another member:

Please email any questions you have to marineservice"at"jrcamerica.com.

We try to answer all questions the same day if possible

[unclemack]

JRC 1000 Radar plugs/sockets are made by JAE, they're SRCN series size 16.

uk.farnell.com stock them, Japan Aviation Electronics has a US website.

Posting this in the hope later searches might find it. Had a hell of a job finding them myself.

[Celestialsailor]

I'm afraid I have some bad news for you. It probably is the magnetron. I have the same model. It worked fine all down the cost to Cabo, then started fading out. I would shut it off for awhile and have a few minutes of life, followed by fading out again. Called JRC and told them the symptoms and they told me, probably the magnetron. This was a year ago and they told me they had no more magnetrons since the unit is obsolete.
I was turned onto Richardson electronics Magnetrons and bought their last one as Japan was not making the magnetron anymore. But who knows, give them a try and let us know.

[stepsmit]

I have a 1000 MK II also. Went to the service outlet in Seattle a couple of years ago and the service guy helped me with mine and took the very last core off the shelf and exchanged it for mine. No charge. He said all service and parts were discontinued about four year ago. Sorry

[Celestialsailor]

Originally Posted by stepsmit

I have a 1000 MK II also. Went to the service outlet in Seattle a couple of years ago and the service guy helped me with mine and took the very last core off the shelf and exchanged it for mine. No charge. He said all service and parts were discontinued about four year ago. Sorry

When you say core, what are you referring to?

[deblen]

I'm an old ret'd Marine Electronics Tech. The Jrc 1000 came on the market about the time I was retiring,so I never had any personal experience with them. I did replace several of the 1st version (not the JRC 1000 MKII) with Furuno or Koden because the 1000 failed early & comm. fishermen don't/can't waste time on troublesome eqpt.
However,they were probably fine for occasional recreational use. I found that magnetrons don't last as long as 3KW & up in most of the little 1.5 & 2KW radars of all brands in comm. use. Like everything,they are built down to a price.

You need to check one more thing before you call it a defective mag. & that is Tuning.

If you have lighted screen (raster),range rings, that proves the display OK.

If you also have noise speckles on screen on long range,with STC(Sea Clutter) turned OFF,FTC (Rain) turned OFF & Gain turned UP, & a heading flash-your antenna is turning & receiver/IF board in the dome is working. The video coax built into the display to dome cable is also OK. A clean screen with rings but no speckle indicates an open video coax. Note: Turning the Gain up & down should make the speckle come & go.

If you still have no targets & no "fuzzy thick donut" rings in the first mile or less,check the tuning bar graph at top of screen on long range. It should be going up & down some as the antenna turns & hits targets. The closer the target the higher the graph-it is measuring the strength of echos rec'd.
If tuning indicator is low & not fluctuating, you can try manual tuning per your owner/installation manual.

If manual tuning doesn't produce targets it's a good indication mag. is not transmitting. The driver ckt board (Modulator) could be defective but you need a Tech for this. Caution!! 5Kvolts at mag-modulator board will burn a nice deep hole in your poking finger.

Having to manually tune usually means the mag. is getting tired & will soon quit.
Fuzzy donut rings are another indication of a mag. on it's way out.
Turning radar to standby & waiting for a few minutes for mag. heater to cool,& then switching back to transmit will sometimes shock a dying mag. into working for bit but it is dying.
The magnetron is a tube-the last tube still in use probably-& they wear out. They are rated for 1000 hrs but some go much longer though usually at poorer performance-more sea clutter & less distance.

I Googled for a JRC1000 manual/diagram to identify the mag. used but no joy. Lots of MKII manuals but I don't know if mags were the same.

Remove the dome cover & ID the mag.
Here is a x-ref list,but it won't surprise me if it's NA as JRC also make mags & have discontinued others Radar Replacement Guide
JRC built small radars for Raytheon for yrs & some of those are mags are NA.
Best to stick with Furuno or Koden-they build the majority of small radars regardless of whose logo is on them.

I can't recommend you drop $US500 for a new mag for that radar-it is quite a gamble. Shop Ebay.

Cheers/ Len

[unclemack]

Did have a look around earlier, many sources say that the 1000 and 1500 use a magnetron designated M1516 and that they're no longer manufactured.

Bummer

[sueanderic]

Hi,
I have a radar dome left over from my JVC 1000. The control unit stopped working after 4 years and about 5 hours use.
You can have the radar dome cheap. It is practically band new.
cheers, Eric

[massey1010]

Cheap sounds great-I'm retired leaving Florida in a few days for home in Toronto where are you located? If you want to go off line I am at murray.russell@sympatico.ca thanks!!

[Celestialsailor]

I love seeing this...cruiser helping cruiser...