Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 08-12-2013, 17:35   #31
Registered User
 
SvenG's Avatar

Join Date: Oct 2009
Location: Mexico heading South
Boat: Ericson 39B - Senta II
Posts: 1,169
Re: ICOM 802 Power Draw When Off

Quote:
Originally Posted by btrayfors View Post
Fact is, MOST if not all ham radios, marine radios, military radios, land-mobile radios, etc. do in fact have such a connection, i.e., there is a dead short between the -VE power connector and the chassis.
That didn't make any sense to me as the ICOM 803 instructions specifically state:

Quote:
Undesirable ground points
Engine block
Ship's DC battery ground
So I went and measured and confirmed that it is indeed correct for the 802, the chassis is connected to negative.



-Sven
__________________

__________________
Senta II - http://www.Grenander.com/Senta_II/Blog/Blog.html
1977 Ericson 39B -- Hull # 216
SvenG is offline   Reply With Quote
Old 08-12-2013, 18:33   #32
Registered User

Join Date: Apr 2007
Posts: 718
Re: ICOM 802 Power Draw When Off

Quote:
Originally Posted by SvenG View Post
That didn't make any sense to me as the ICOM 803 instructions specifically state:

Undesirable ground points
Engine block
Ship's DC battery ground
That is in reference to the RF ground. Even though they are connected, don't rely on the engine block and/or DC battery ground as your RF ground.

Eric
__________________

__________________
fairbank56 is offline   Reply With Quote
Old 08-12-2013, 19:02   #33
Registered User
 
SvenG's Avatar

Join Date: Oct 2009
Location: Mexico heading South
Boat: Ericson 39B - Senta II
Posts: 1,169
Re: ICOM 802 Power Draw When Off

Quote:
Originally Posted by fairbank56 View Post
That is in reference to the RF ground. Even though they are connected, don't rely on the engine block and/or DC battery ground as your RF ground.

Eric
I wish you hadn't cut the rest of what I wrote:

Quote:
So I went and measured and confirmed that it is indeed correct for the 802, the chassis is connected to negative.


-Sven
__________________
Senta II - http://www.Grenander.com/Senta_II/Blog/Blog.html
1977 Ericson 39B -- Hull # 216
SvenG is offline   Reply With Quote
Old 08-12-2013, 19:02   #34
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Re: ICOM 802 Power Draw When Off

One more good reason not to connect the ground lug on the chassis to the DC Neg bus. You are just asking for ground loops in that case.

Bill, do you connect the chassis grnd. point to a ground rod? When I lived in a house and was an active ham I had a ground rod through the basement floor under the Transceiver location. When I installed my ham radio on a boat I did not use that connection.
__________________
The Blue Dot Campaign. This Changes Everything.
DeepFrz is offline   Reply With Quote
Old 09-12-2013, 05:59   #35
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Re: ICOM 802 Power Draw When Off

Quote:
Originally Posted by DeepFrz View Post
One more good reason not to connect the ground lug on the chassis to the DC Neg bus. You are just asking for ground loops in that case.

Bill, do you connect the chassis grnd. point to a ground rod? When I lived in a house and was an active ham I had a ground rod through the basement floor under the Transceiver location. When I installed my ham radio on a boat I did not use that connection.
No, I don't use the ground lug on the chassis, especially not in a marine installation. It can create undesirable ground loops and, anyway, the chassis is "grounded" thru the negative power cable.

In shore installations, a good station ground is usually desirable to help bleed off static electricity coming down the coax and generally to quiet the reception.

Bill
WA6CCA
__________________
btrayfors is offline   Reply With Quote
Old 09-12-2013, 09:07   #36
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Quote:
Originally Posted by btrayfors View Post

No, I don't use the ground lug on the chassis, especially not in a marine installation. It can create undesirable ground loops and, anyway, the chassis is "grounded" thru the negative power cable.

In shore installations, a good station ground is usually desirable to help bleed off static electricity coming down the coax and generally to quiet the reception.

Bill
WA6CCA
Maybe it's a radio thing. But cases connected to DC negative are real bad, as you can inadvertently create un intended DC return paths. ( Like two cases touching ) , Very nasty. Must measure my VHF cases.

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 09-12-2013, 15:58   #37
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
Re: ICOM 802 Power Draw When Off

Quote:
Originally Posted by btrayfors View Post
No, I don't use the ground lug on the chassis, especially not in a marine installation. It can create undesirable ground loops and, anyway, the chassis is "grounded" thru the negative power cable......
Bill
WA6CCA
FWIW, on marine installations where there are dedicated radio racks and cabinets complete with earthing bars (and equipotential bonding etc), we usually connect the chassis ground lug to the rack / cabinet earth bar. If no earth bar is available, we leave it unconnected. Not saying this is right or wrong, just saying it is how we do it. These racks usually have their own dedicated DC supplies from the ship's main AC source and the DC -ve is either floating or else tied to the rack's ground bus

In light of Dave's "idiot engineers" comment, I did come across one installation of a DC supply in a rack where the original installers (designers??) fitted the AC/DC convertor with the +ve side as the "common" (but not tied to the ground bus) and the -ve side as the fused distribution side. This made the radio chassis "live" with -12 volts with relation to the DC "ground" in that rack.

The other racks nearby all had the convertors wired in the more manner. It took a few minutes of head scratching to work out what was going on. Once the customer was advised, he soon had us re-working that particular convertor. Strange things happen off-shore
__________________

__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Reply

Tags
icom

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
From My Design to My Installation: New AC Power System s/v Jedi Electrical: Batteries, Generators & Solar 88 24-10-2017 09:35
Icom 802 and Pactor Modem Issues nhschneider Marine Electronics 14 03-03-2015 12:55
12v system for everything? simonpickard Electrical: Batteries, Generators & Solar 34 16-09-2013 13:21
Want To Buy: Icom 802 SSB Overlord Classifieds Archive 1 13-10-2011 05:37
ABYC Power Feeder Code E-8.11.4.1 vs E-8.11.9.2.1 sdowney717 Electrical: Batteries, Generators & Solar 27 09-07-2011 10:47



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 17:00.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.