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I have been reading about the MP-1 whip with some interest and am
wondering about the contruction. I am assuming that the coil and
cover assembly work like an inverted screw driver antenna, i.e., the
cover slides down over the coil from the top. What is not clear from
the pictures of the MP-1, is the construction of the cover. I though
a couple of questions might be in order for those of us who might
want to home brew one of these.
1. Is the outer cover constructed from or contain a metal sleve that
capacitively shorts out the covered portion of the coil like on the
screw driver antenna (eliminates current loops in shorted portion of
coil).
2. Does the coil shorting contact use a single point contact, or a
continous (circular) contact made from finger stock or a spiral wire
oring gizmo (always liked that word).
3. I am also assuming that the MP-1 works better when an extention
is inserted under the coil to get it up the whip a few feet.

73,

Jim Zellmer, KA0VSL

--- In FT817@y..., zellmer@r... wrote:

I have been reading about the MP-1 whip with some interest and am
wondering about the contruction. I am assuming that the coil and
cover assembly work like an inverted screw driver antenna, i.e.,

the

cover slides down over the coil from the top. What is not clear

from

the pictures of the MP-1, is the construction of the cover. I

though

a couple of questions might be in order for those of us who might
want to home brew one of these.
1. Is the outer cover constructed from or contain a metal sleve

that

capacitively shorts out the covered portion of the coil like on the
screw driver antenna (eliminates current loops in shorted portion

of

coil).

Yes.

2. Does the coil shorting contact use a single point contact, or a
continous (circular) contact made from finger stock or a spiral

wire

oring gizmo (always liked that word).

A continuous contact made of finger stock.

3. I am also assuming that the MP-1 works better when an extention
is inserted under the coil to get it up the whip a few feet.

Many have stated this, although I don't have an extension so haven't
tried it. Of course, with that, you would lose the MP-1's advantage
of packing down to a short length, in which case other, longer whips
could be considered as an alternative.

Julian, G4ILO

--- In FT817@y..., zellmer@r... wrote:

I have been reading about the MP-1 whip with some interest and am
wondering about the contruction. I am assuming that the coil and
cover assembly work like an inverted screw driver antenna, i.e.,

the

cover slides down over the coil from the top. What is not clear

from

the pictures of the MP-1, is the construction of the cover. I

though

a couple of questions might be in order for those of us who might
want to home brew one of these.
1. Is the outer cover constructed from or contain a metal sleve

that

capacitively shorts out the covered portion of the coil like on the
screw driver antenna (eliminates current loops in shorted portion

of

coil).

*** Metal.

2. Does the coil shorting contact use a single point contact, or a
continous (circular) contact made from finger stock or a spiral

wire

oring gizmo (always liked that word).

*** Finger stock.

3. I am also assuming that the MP-1 works better when an extention
is inserted under the coil to get it up the whip a few feet.

*** It already has a small extention that positions the coil somewhat
above the base. This is part of Verne's design.

72 de Barry - W4WB

73,

Jim Zellmer, KA0VSL