VHF / SSB installation

Thread Starter

white_rg

Joined Mar 19, 2008
4
hello to all , i will install a SSB radio on my steel boat [ emission maxi 150 watt ] but i need to ground it .i think it is the same as grounded a SSB radio on "earth" and i read articles on the web telling me that i need to use 0.15 F capacitors but they didn't tell how many and how this value ( 0.15F) was calculated.

So any advices / docs/websites from vhf/hf/SBB "experts" will be greatly appreciated .many thanks in advance
 
Last edited:

beenthere

Joined Apr 20, 2004
15,819
I think you will find the hull is fairly well grounded. Anything electrically tied to the hull is going to be grounded. The water surface makes a really nice ground plane, too.

What function are the capacitors supposed to do?
 

Papabravo

Joined Feb 24, 2006
22,116
I'm curious about what radio service and VHF frequency allocation allows you to exceed 1500 Watts? At those power levels you will want to conduct an RF safety evaluation and make sure nobody can get an RF burn from putting their lips on the antenna with the PTT key down. Have your ever seen an RF burn? Nasty buggers!
 

thingmaker3

Joined May 16, 2005
5,083
Depending on frequency and circumstances of exposure, those power levels can cause cataracts and/or sterility in addition to burns
 

Thread Starter

white_rg

Joined Mar 19, 2008
4
hello to all ,

thank for your responses , sorry but i think a mistake i should have write : emission maxi 150 watt .I am very confuse because the dealer i went to see was more "seller" than technician ( Furuno SSB )

"What function are the capacitors supposed to do?" i dont know , because he refused to give me the details of the ssb installation ( a good SBB is [ very ] expensive ); for what i have read i think when the sbb is emetting , there is an electric arc
maybe the function of the capacitors is for that.
 
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loosewire

Joined Apr 25, 2008
1,686
White RG -Go to (http--www.frallon.us-ssb.pdf ) Help guy's find this site and give a
click on to help.The explaination of grounding on boat's will be helpful, the curcuit
information may used in the e-book. I think it excellent information,check out the
theory.Check out plated copper Vs copper wire to ground.How many star's.
LOOSEWIRE
 

Papabravo

Joined Feb 24, 2006
22,116
Depending on features and frequency bands an SSB radio is not necessarily an expensive proposition compared to a ship. 150 Watts is a reasonable power level for a marine radio in the HF region of the RF spectrum, 3 MHz - 30 MHz. Prices for an SSB rig for the HF bands should be in the $300 - $3000 range. You said these were VHF radios which implies a coverage in the 30 MHz - 300 MHz region of the RF spectrum. In the VHF spectrum this power level may well get you into more expensive territory.

My 2 meter (144- 148 MHz.) base station is an ICOM 2200. It puts out 65 Watts and cost $130.00. It is not an SSB rig, but a narrow band FM. For independent advice on your radio decisions check out a local amateur radio club. With any luck you'll find an Elmer (mentor) more than willing to give you some help and advice for a ride on the boat.
 

JoeJester

Joined Apr 26, 2005
4,390
I've read the article. It mentioned steel hulls don't have the ground plane problems that occur with fiberglass hulls. It doesn't address the specific issue the OP had in mind (the capacitors).

For the OP (original poster):

I'm curious as to why the purchased radio didn't have an installation manual. What is model and manufacturer of your radio? Manufacturers don't typically leave you hanging high and dry (so to speak).
 

Papabravo

Joined Feb 24, 2006
22,116
I've read the article. It mentioned steel hulls don't have the ground plane problems that occur with fiberglass hulls. It doesn't address the specific issue the OP had in mind (the capacitors).

For the OP (original poster):

I'm curious as to why the purchased radio didn't have an installation manual. What is model and manufacturer of your radio? Manufacturers don't typically leave you hanging high and dry (so to speak).
Unscrupulous dealers might have no qualms about sticking it to you however.
 

Externet

Joined Nov 29, 2005
2,668
For the HF transceiver, the best suggestion I can give after earning a living in marine electronics is to make a bronze puddle of at least a couple inches diameter by brazing onto solid ultraclean grinded-to-shiny metal and weld an at least ½" bronze bolt head down to the puddle to connect your coaxial shields, all this done next to the base of the antenna and antenna tuner location. Use flat bronze washer and bronze nut.

After VERY solid soldered terminals are attached and all tests good, pour silicone sealer around.
The ship/transceiver battery must have negative to hull.
The 2m VHF antenna is usually colinear and requieres no grounding. But make sure its cable does not flag around.
Miguel
 
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