Thread: SSB Antenna
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Chuck
 
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Default SSB Antenna

Hello Jerry,

I'm not sure I understand exactly what you want to
do. It seems you want to simply use the shroud as
a support for an insulated wire, which would be
your antenna. This would allow you to avoid a
direct (DC) connection between the antenna wire
and the shroud. I think that if the shroud were
non-conducting, your idea would work well. If the
shroud is metal, which is most likely, then I
believe you will transfer energy to the shroud
which in turn will radiate and provide a means of
producing RF burns.

A better solution might be to slip some rubber or
teflon tubing over the shroud up to a height of
say six feet. You might slit the tubing to allow
attachment without disconnecting the shroud. Then
you could attach your short feed length of wire
from the tuner directly to the shroud and you're
in business. Do the same on the other shroud and
it may even look nice.

If that is not attractive, you could run a length
of nylon or dacron line from someplace on the hull
to the mast (or use a flag halyard) and pull an
insulated wire antenna up to some pre-determined
height that way. You will still get some coupling
into the rigging from any antenna anywhere on the
boat. Usually (but not always) there is little
danger of RF burns. One advantage of this
technique is that you can get the antenna to be a
quarter wave at some desired frequency--an option
not available with the shroud antenna.

Have I missed the boat? Hope that helps.

Chuck


Jerry Peters wrote:
I have been researching SSB installation issues and am left with a couple of
questions.

First, antenna installation. I intent to use a long wire through a tuner to
operate on HF. I intend to use an insulated shroud (I have a cat with no
backstay) with a short feed from the tuner. I have always believed that the
feed wire should be seaparated from the rigging before it reaches the
connection point to reduce capacitive reactance. I have accomplished this
in the past with 2" spacers holding the wire off of the shroud until it
reached the connection point. Recently, I read a credible opinion that
separation of an inch or two is irrelevant at high frequencies because to
eliminate all capacitive reactance the seaparation would have to be meters.
The capacitive reactance that does exist can be accomodated with the tuner.
If this is true I would prefer to directly attach a long insulated wire to
the shroud - perhaps tape it over a 25 foot length. It would be out of the
way, safe from rf burn risk and would not require the installation of
rigging isolators which introduce mechanical weakness and expense.

My second set of questions relate to ground plane/counterpoise installation
but I'll hold of on those quetions for the moment.

Thanks for your help.