RDP-149 Signal Issues

[BrennanC]

Hello,

I have an RDP-149 being used as a radar repeater, slave to an RDP-150. The RDP-150 is not having an issue, but when the RDP-149 is energized, the radar returns start out as one would expect, crystal clear, exactly what you want to see. Then after 15 minutes or so, the image quality starts to degrade around the center of the vessel. Finally, you start to see 95% returns across the scope, almost like your gain was cranked and all the suppression turned off. This follows the sweep intermittently for a few minutes. During this time, you can adjust for the excess noise, but then when things go back to normal after a few minutes, you're over compensated in the wrong direction. Any idea what is going on here? Again, the primary display is having no issue which seems to rule out the antenna or outside interference?

Thanks,
Brennan

 

[Johnny Electron]

It sounds like the RDP150 option output has an signal amp going bad or the RDP149 input processor has a spu board going bad. It would help if you could use a different RDP149 or older RDP139 to run for a bit to see if the problem goes away or stays. If goes away; it is the RDP149 issue but if it stay the RDP150 has a problem. While the cable could be an issue, it is doubtful unless someone is moving it around.

 

[BrennanC]

Well I have two RDP150's, with only one networked with the RDP149 so swapping them could reveal the issue. Unfortunately in doing so, I accidentally removed the ribbon cable to the display. I plugged it back in but now the screen is inverted, text upside down, everything. Any chance I put the ribbon in backwards?

 

[Johnny Electron]

When you say ribbon cable, your talking about the RDP149 slave radar cable going into the option port of the (RDP150) radar? The inverted image is on the RDP149 not the master RDP150, correct?

 

[BrennanC]

Sorry, the inverted display is on the master unit, the RDP 150. The ribbon cable I mentioned is the one going to its LCD screen.

 

[BrennanC]

Follow up: the ribbon cable had a pin that was not fully seated upon reinsertion and bent back. Flattened it back out and it's working as usual now. Charles Hyde of Hyde Marine Instrumentation helped me figure it out.

 

[Johnny Electron]

You are braver than I. I hate all the ribbon cables in the RFP150. It is like a mine field.

 

[BrennanC]

You are braver than I. I hate all the ribbon cables in the RFP150. It is like a mine field.

Lol, bravado of the ignorant, perhaps.

I went ahead with the RDP-150 swap and the worst of the effects on the remote RDP-149 have subsided, but now the unit slowly pulses from a pretty good image to one with only the strongest targets visible. I suppose I'm looking at a failing SPU board on the 149 at this point unless I just got really unlucky and both 150's have failing signal amps?