View Single Post
  #5   Report Post  
Larry W4CSC
 
Posts: n/a
Default

"Alfred Bauer" wrote in
:

Is this true ?


Yes, he's right. You only need to bond the TUNER ground to the aluminum
hull the shortest way possible with the least bends. It's not DC or low
frequency AC. If anything gets near the hull that conducts, it will couple
the HF signal to it..especially sea water. With that aluminum hull, you
will be able to have a potent signal even if the boat is on blocks in the
parking lot. The tuner needs an RF ground, which is as simple as a 1/4
wavelength piece of wire laid out going nowhere. 1/4 wavelenght back from
the open end of that wire is an "artificial ground", also called a ground
plane. Your local AM radio station uses buried bridge cables that radiate
in all directions out from the base of the tower, which is itself the
antenna on AM radio, out 1/4 wavelength. They bury them so they don't get
tangled up in the lawn mower.


Can this work ?


Sure wish such a great ground were easy to get to in a fiberglass sailboat.
Our Icom M802's AT130 tuner is strapped to the engine block and uses the
boat's ground system from there. Works fine. I worked Japan on the ham
bands from Charleston, SC. That's about as far as you can get.


Has any one experience with SSB grounding on aluminium hulls.


You won't be on the air long enough or be running enough power when you are
to eat holes in the hull from the RF current of such a small transmitter.
A Canadian fishing trawler was being outfitted here as a pirate radio
station with a 70KW shortwave transmitter. The US government's FCC swept
down on them and confiscated everything before it got to sea. One problem
they didn't solve was the huge RF current from such a big transmitter into
the seawater was eating holes in the bottom of the steel boat! Their first
indication something bad was happening is when they got up for breakfast
one morning and the fresh water system was salt water....


--
Larry W4CSC