[TG] [TG11] Axiom 12 can't find Radome

[Tom - Raymarine - Moderator]

Hello Vettepro,

I should be careful here not to contradict local guidelines or practice - I'm in Australia and our bonding practices are no doubt different in some details to yours - but the key thing from the point of view of an RF drain is a single point, with the drain wires of all of the products at a common potential. This usually involves bringing the drains of the electronics at a helm station to one junction and then running a single cable from there to whatever your RF ground is. You should not have multiple different paths back to that RF ground.
Here in Australia the common practice amongst electronics installers is to connect drains to the negative bus-bar, which then will generally go via the battery negative stud to the engine block. Because we have a high preponderance of aluminium vessels I am always very careful to advise owners not to make their own connections to new 'grounding' points. In theory the boatbuilder or original installer has planned the DC grounding or isolation and I would say that it's important to maintain the scheme they've used and not make new connections to earth.

By the way, since I'm in a different part of the world, I'll clarify the way I am using the terminology:

• Earth: sea-water potential.
• Ground: the reference potential used to drain away noise from electronic systems. Not current-carrying. Product drain wires and ground tags connect here.
• Supply negative: the current-carrying return - battery negative or equivalent. May be bonded to earth or be isolated/above-earth, depending on vessel and system design.
• Bonding: the practice of joining vessel metalwork to a common potential to reduce galvanic corrosion.
  

On the power supply - running your own cable is a good test, and this proves that you don't have a significant power supply drop between the battery and connection point, but does not absolutely rule out supply as the cause. I know it's a new radar cable and *should* be fine...

Regards,
Tom