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Allagator
Advanced Member
Username: Allagator
Post Number: 809
Registered: 9-2002
| | Posted on Tuesday, November 01, 2011 - 6:33 pm: | 
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I just got a 18 foot fiberglass boat and im wanting to mount a 102 whip on it for 10m but how would i ground it to get a nice match ? also mounting a 20m and a homebrew 40m antenna ! any ideas on how to ground them for a good ground ??
CEF 115 / CEF HAM 290 /KC9OKX
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Moonraker
Intermediate Member
Username: Moonraker
Post Number: 293
Registered: 3-2005
| | Posted on Tuesday, November 01, 2011 - 8:06 pm: |
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If the boat doesn't have a steel hull I would try a making a counterpoise with some insulated wire. It will probably end up around 8 1/2 feet but I would start at 9 and trim if necessary. Lay the wire flat along the side of the boat. I'm not an antenna expert but that would be my first attempt. |
Allagator
Advanced Member
Username: Allagator
Post Number: 813
Registered: 9-2002
| | Posted on Wednesday, November 02, 2011 - 3:13 pm: |
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ill try that Moonraker ! i build antennas all the time but its easy when its not a boat ! LOL now that has me all tied up in coax ! Thanks Again !
CEF 115 / CEF HAM 290 /KC9OKX
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Allagator
Advanced Member
Username: Allagator
Post Number: 817
Registered: 9-2002
| | Posted on Sunday, November 06, 2011 - 3:17 pm: |
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first test with the 102 and it was good on dry ground but when i stuck it in the water WOW !!! it went haywire ! SWR off the boat ! and soon as i pulled it out of the water it was ok again ! something changes with the water and the way the antenna works !
CEF 115 / CEF HAM 290 /KC9OKX
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Moonraker
Intermediate Member
Username: Moonraker
Post Number: 295
Registered: 3-2005
| | Posted on Sunday, November 06, 2011 - 6:31 pm: |
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That's interesting. I don't have any ideas but I would like to hear an explanation as well. |
Tech237
Moderator
Username: Tech237
Post Number: 1487
Registered: 4-2004
| | Posted on Monday, November 07, 2011 - 9:28 am: |
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Take a look around, there are antennas designed for fibreglass boats. I think I may have the instructions for one amoing my antenna files. I'll look and if so see about posting on the forum.
Of course something changes with the water - your groundplane improves. How close is the antenna to the motor? If close enoght you could use a heavy strap to the motior for ground, or even to a copper plate glued to the hull. In the past, I have used both methods to supply a good groundplane on boats that are used for maritime rescue.
Tech237
N7AUS
God only made some many perfect head, on the rest he put hair.
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Allagator
Advanced Member
Username: Allagator
Post Number: 819
Registered: 9-2002
| | Posted on Monday, November 07, 2011 - 1:59 pm: |
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There is a metal rail with a mirror mount for the 102 and i ran a #0 welding cable to the 350 inbored motor from the underside to hide it ! gona hit the water again this week and try it again !
CEF 115 / CEF HAM 290 /KC9OKX
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Barracuda
Intermediate Member
Username: Barracuda
Post Number: 346
Registered: 3-2003
| | Posted on Monday, November 07, 2011 - 3:44 pm: |
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Tie the ground side of the coax to anything on the boat that is metal and is in contact with the water that the boat is sitting in. |
Allagator
Advanced Member
Username: Allagator
Post Number: 822
Registered: 9-2002
| | Posted on Monday, November 21, 2011 - 1:43 pm: |
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Well i got my antennas working ! Thanks guys !!!!
Gona haul it down to the river and spend the next weekend on the river waiting for the net !!!
CEF 115 / CEF HAM 290 /KC9OKX
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