Humminbird Side Imaging Forums
Other Interest => DIY - Side Scan Sonar and towfish => Topic started by: bigkahuna on January 06, 2012, 08:28:33 AM
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Anyone ever try opening up their HB unit? I'm wondering if the internal components of a 798 ci hd si might be removed from the original housing and fit into a water tight cylindrical housing with a 4" diameter. That way I could use the ethernet connection and wouldn't experience signal degradation from extending the transducer cable too far. Anyone have photos of the insides of a unit?
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Hi,
I have seen some photos from circuit boards here:
http://www.xumba.scholleco.com/viewtopic.php?t=3084&highlight=international (http://www.xumba.scholleco.com/viewtopic.php?t=3084&highlight=international)
http://www.xumba.scholleco.com/viewtopic.php?t=672&postdays=0&postorder=asc&highlight=international&start=15 (http://www.xumba.scholleco.com/viewtopic.php?t=672&postdays=0&postorder=asc&highlight=international&start=15)
The boards look rather big...
Rickard
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Darn! You're right, looks like the board fills almost the entire housing. I'm sure it's a multi layer board so no chance of cutting it without major issues. Hmmm... back to the drawing board...
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The PCB is about 5 inches X 6.5 inches.
Yep, multilayered: try 8 layers with ground planes on both the primary and secondary sides. Makes it really tough to solder to especially when combined with the lead-free solder and size of some of those components!
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@Greg - Do you happen to know the dimensions of the 898 motherboard? The 898 is longer and not so wide so that might be a possibility.
[Seems a shame to tear apart a perfect good $1400 unit to put it in a tube. Maybe I should hang out behind the Humminbird factor and pick up one of their scratch and dent units. ;) ]
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4.25 X 9.5 inches for the main PCB of the 898c Si unit.
When we scratch and dent them they are usually in many pieces bigkahuna. It’s a great way to relieve work stress!
[Actually we recycle most everything.]
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Some people bake/pot their boards in plastic/epoxi/resin, then there is no need for a waterproof housing.
Rickard
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that only protects the board and components, not the wires / circuits that it will be connected to. If there were an easier way, I'd do it. :)
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Hi big k
You not only need an ethernet connection but also a power supply.
So I think that the effort with a waterproof housing is not worthwhile, just to make a potentially long cable connection.
mvh
Rüdiger
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These guys use potting instead of housings whenever they can:
http://www.submarineboat.com/waterproofing.htm (http://www.submarineboat.com/waterproofing.htm)
Rickard
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It seems I've hit a topic you fellows have thought about as well...
@Rüdiger - You're assuming my plan is to use this in a towfish, which it is not. My application will have more than sufficient power for the sonar unit.
@Rickard - Thanks, I've got a fair bit of experience in designing and building submersibles. There are good applications for potting electronics and then there are situations where it would be of limited benefit, I believe in this instance it is the latter.