Another RF ground ?? - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 07-23-2014 Thread Starter
Senior Member
 
Join Date: Dec 2013
Location: Orlando
Posts: 109
Thanks: 36
Thanked 5 Times in 5 Posts
Rep Power: 2
 
Another RF ground ??

Our 1989 PSC34 has a dyna plate attached to the hull. The new electronics I m installing on board are calling for attachment of an RF ground...the power cables have three wires: Positive, Negative, and RF ground.

The manuals specific attaching RF ground to an RF grounding system or the negative terminal of the battery.

Would attaching the rf ground wires to the Dyna plate suffice?

Wouldn't attaching the rf ground wire to the negative bus bar be the same as attaching to the negative terminal of the battery?

Are there any other methods to create an rf ground to attach all the rf ground wires too?
Hush34 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 17 Old 07-23-2014
Full-time Liveaboard
 
CaptainChaos's Avatar
 
Join Date: Oct 2012
Posts: 36
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Another RF ground ??

The dyna plate is a typical RF ground especially for the SSB. What type of electronics are you installing that need the RF ground?

Attaching to the negative bus bar is similar to but not as good as connecting directly to the battery. The battery will do a marginally better job at sinking the RF currents.

Walt

s/v Wanderlust
Passport 545
CaptainChaos is offline  
Quote Quick Reply Share with Facebook
post #3 of 17 Old 07-23-2014 Thread Starter
Senior Member
 
Join Date: Dec 2013
Location: Orlando
Posts: 109
Thanks: 36
Thanked 5 Times in 5 Posts
Rep Power: 2
 
Re: Another RF ground ??

My VHF, Multifunction Display and autopilot require separate RF ground. I was think about connecting to the plate but I am a bit concerned about the fact that the mast is grounded there and that a lightening strike would kill everything attached.
Hush34 is offline  
Quote Quick Reply Share with Facebook
post #4 of 17 Old 07-23-2014 Thread Starter
Senior Member
 
Join Date: Dec 2013
Location: Orlando
Posts: 109
Thanks: 36
Thanked 5 Times in 5 Posts
Rep Power: 2
 
Re: Another RF ground ??

My VHF, Multifunction Display and autopilot require separate RF ground. I was think about connecting to the plate but I am a bit concerned about the fact that the mast is grounded there and that a lightening strike would kill everything attached.
Hush34 is offline  
Quote Quick Reply Share with Facebook
post #5 of 17 Old 07-23-2014
Senior Member
 
Join Date: Jan 2007
Location: The house is in Kingsport, TN. Boats are on Watauga Lake and in New Bern, NC
Posts: 239
Thanks: 2
Thanked 27 Times in 23 Posts
Rep Power: 9
 
Re: Another RF ground ??

Your boat may have a copper HF radio ground strap built into the boat. See the older thread:

Grounding a SSB radio in a PSC 34

Bill Murdoch
1988 PSC 34
Irish Eyes
wsmurdoch is offline  
Quote Quick Reply Share with Facebook
The Following User Says Thank You to wsmurdoch For This Useful Post:
Hush34 (07-24-2014)
post #6 of 17 Old 07-23-2014
Full-time Liveaboard
 
CaptainChaos's Avatar
 
Join Date: Oct 2012
Posts: 36
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Another RF ground ??

Quote:
Originally Posted by Hush34 View Post
My VHF, Multifunction Display and autopilot require separate RF ground. I was think about connecting to the plate but I am a bit concerned about the fact that the mast is grounded there and that a lightening strike would kill everything attached.
Are you sure your mast is grounded to the dyna plate? I have some knowledge of RF but am not an expert. However, I believe the RF ground and the lightning protection system should be separate as they serve very different functions.

Walt

s/v Wanderlust
Passport 545
CaptainChaos is offline  
Quote Quick Reply Share with Facebook
post #7 of 17 Old 07-24-2014
Mermaid Hunter
 
SVAuspicious's Avatar
 
Join Date: Oct 2006
Location: on the boat - Chesapeake
Posts: 3,984
Thanks: 0
Thanked 158 Times in 141 Posts
Rep Power: 9
 
Re: Another RF ground ??

The issue here is different from the RF ground appropriate for an SSB. The cables that interconnect your electronics are shielded to minimize the potential for radio frequency interference (RFI). RFI may cause data disruption. Autopilots are particularly prone to unfortunate responses to RFI. Stories of 90 degree turns when a radio is keyed abound.

In your case connecting the shield to the battery negative will be most effective. Unless you are confident that you can avoid ground loops you are best served using the negative bus bar for the shield connections.

In the long term you should understand ground loops (bad) and single point grounds (good). Realize that there are a number of ground systems on your boat: DC ground (battery negative), AC safety ground (the green wire), AC neutral (the white wire which may will have a connection to the safety ground at inverters or generators), RF ground, a lightening ground (apparently on your boat but not on all), and possibly a galvanic bonding system. There are relationships between the various grounds and the interconnections should be in association with a single point ground.

sail fast and eat well, dave
S/V Auspicious
AuspiciousWorks.com
beware "cut and paste" sailors.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
SVAuspicious is offline  
Quote Quick Reply Share with Facebook
The Following User Says Thank You to SVAuspicious For This Useful Post:
Hush34 (07-25-2014)
post #8 of 17 Old 07-24-2014 Thread Starter
Senior Member
 
Join Date: Dec 2013
Location: Orlando
Posts: 109
Thanks: 36
Thanked 5 Times in 5 Posts
Rep Power: 2
 
Re: Another RF ground ??

Each one of my chain plates hence the mast are hardwired to the dyna plate. I think I am going to stay away from attaching RF ground to the plate and stick to the negative bus bar ie, the negative terminal of the battery.
Hush34 is offline  
Quote Quick Reply Share with Facebook
post #9 of 17 Old 07-24-2014
Full-time Liveaboard
 
CaptainChaos's Avatar
 
Join Date: Oct 2012
Posts: 36
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Another RF ground ??

Quote:
Originally Posted by Hush34 View Post
Each one of my chain plates hence the mast are hardwired to the dyna plate. I think I am going to stay away from attaching RF ground to the plate and stick to the negative bus bar ie, the negative terminal of the battery.
That's probably the best solution. Again, I question whether the chain plates, etc. are connected to a dyna plate. More likely they're connected to a normal grounding zinc.

Walt

s/v Wanderlust
Passport 545
CaptainChaos is offline  
Quote Quick Reply Share with Facebook
post #10 of 17 Old 07-25-2014 Thread Starter
Senior Member
 
Join Date: Dec 2013
Location: Orlando
Posts: 109
Thanks: 36
Thanked 5 Times in 5 Posts
Rep Power: 2
 
Re: Another RF ground ??

I replaced every chain plate on the boat in February and attached to each was infact an 8 gauge wire that ran from the backing plate to the dyna plate which is on the starboard side of my boat.

Today I did some rewiring so I could finish the install of my auto-pilot. Back in 1989 they really thought Loran was going to be around forever....took me a while to cut all the tie wraps to release the dead end loran cable which is where I ran power to my Seatalk network from.

As for the RF ground, I found a 8/0 ground cable that I believe goes directly t the battery that I am going to use for my RF grounding. I am installing a bus bar so all my electronics that need RF grounding can be attached. Thanks for all the input on this subject it has been a real help.
Hush34 is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Is this a ground leak? ccriders Gear & Maintenance 2 10-30-2008 11:37 AM
Ground leak? patja Gear & Maintenance 7 09-24-2008 09:36 AM
ground transport falconev General Discussion (sailing related) 21 03-04-2008 10:23 PM
Where to Ground to?? elvisnpriscilla Gear & Maintenance 6 03-05-2003 09:59 PM
Ground for AC System fesivo Gear & Maintenance 1 01-23-2001 09:47 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome