Instruction manual

From March 2009 QST © ARRL
Table 1
High End Dual Lever Paddle Summary
Model Return, Bearings and Base Hardware and Contacts Dislodging Fingerpieces Weight Price
Pressure* (lb)
N2DAN Attracting magnetic return; Coarse threads, locknuts; 1.6 oz/ Long flecked dark purple 3.78 n/a
Mercury Four race bearings; Long and heavy levers; 2.8 oz rounded plastic; 1.1 to (incl
Chrome-plated steel base Flat rhodium-plated 2" above operating mem
silver contacts surface buttons)
Bencher Attracting magnetic return; Coarse threads, locknuts; 1.6 oz/ Long black rounded 3.49 $495
Mercury Four race bearings; Chrome-plated brass 2.3 oz plastic; 1.1 to 2" above (plus s/h)
Chrome-plated brass base levers; Convex gold- operating surface
plated silver contacts
GHD Compression spring return; Medium threads, locknuts; 1.4 oz/ Long rounded clear 2.84 $400
GN599DX Four race bearings; Long and heavy levers; 1.6 oz acrylic; 0.9 to 2" above (plus s/h)
Chrome-plated steel base Flat gold-plated silver operating surface
†
contacts at a 45° angle
Frattini Repelling magnetic return; Medium threads, locknuts; 2.5 oz/ Long red rounded 3.48 $425
Professional Spherical bearings; Brass levers; Flat 2.1 oz triangular plastic; 0.6 to (incl s/h)
Deluxe Coated brass base sterling silver contacts 2" above operating
surface
Begali Repelling magnetic return; Fine threads (no locknuts); 1.6 oz/ Short rounded black 2.87 €400 (incl
Sculpture Four sealed race bearings; Light alloy levers; Convex 1.9 oz carbon fiber; 0.4 to 1.9" s/h)
Stainless steel base solid gold contacts above operating surface
†
N3ZN Bronze Repelling magnetic return; Fine threads (no locknuts); 1.1 oz/ Short rounded trapezoidal 2.11 $295
Model ZN-9A Six ball bearings; Aluminum levers; 1.2 oz black carbon fiber; 0.8 to (plus s/h)
Coated bronze base Points touching convex 1.8" above operating
gold-plated silver contacts surface
†
*Lateral finger pressure required to move the paddle on a laminate surface and with a friction mat. See text.
†
Optional fingerpieces are available. See manufacturer’s Web site for details.
contacts. Only a high quality paddle attains
that standard. Rhodium is expensive, highly
resistant to corrosion, and very hard.
Even with extremely close adjustment, the
levers are long enough to set up a noticeable
vibration, rather like the dying oscillations
of a bell. That vibration shouldn’t interfere
with good keying; it is simply a constantly
present characteristic of a heavy and lengthy
paddle lever. A long-levered heavy paddle
like the Mercury is probably the best choice
for operators with heavy fists. Having never
passed through the stage of being a skilled
bug operator, I prefer light-touch keying.
Finger pressure of 1.56 ounces on the
levers is required to dislodge the N2DAN
Mercury on a laminate operating surface.
Supplemented with a thin high-friction shelf
pad, that increases to 2.82 ounces — a sub-
stantial improvement.
Very rarely does a classic N2DAN Mer-
cury paddle appear on the used market, and
when one shows up, it can command a very
high price.
BENCHER MERCURY
Fortunately, Steve Nurkiewicz’s widow
sold his Mercury patent and tooling to
Bencher, and so this classic key is still
available. Over its long history, the N2DAN
Mercury changed somewhat. The Bencher
Mercury follows the pattern of the later mod-
els quite closely. The major difference is that
the Bencher version uses gold-plated silver
contacts rather than the rhodium-plated silver
contacts in the N2DAN originals. The contacts
are very slightly convex, an improvement over
the original with its flat contacts. The two
separate ground wires connected to the levers
in the Bencher Mercury are braided and more
robust than those in my N2DAN Mercury.
The Bencher Mercury arrived from the
factory with its anisotropic (directional) at-
tracting magnets set for very strong return
action. The combination of its cork bottom
and 3.49 pounds of weight makes it rock-
solid, even using a heavy fist. Finger pressure
of 1.62 ounces on the levers is required to
dislodge the Bencher Mercury on a laminate
operating surface, increasing to 2.33 ounces
with a friction pad.
Tension can be reduced so low that tilting
the paddle 90° to the left or right triggers
the dit or dah circuits. Just like the original
N2DAN Mercury, the long levers produce a
slight vibration when paddling. The fixed fin-
reliable indicator, he probably produced only
a few hundred paddles during his lifetime.
I acquired #241, made in January 1994,
and supplemented it with a bracket of four
pushbuttons to control keyer memories. Steve
passed away in 1997, but his legacy lives on
through the fists of the fortunate operators
who have acquired an N2DAN Mercury.
During a period when most paddle users
had learned lateral motion Morse on semi-
automatic bugs, Steve’s philosophy com-
bined close-tolerance machining with heavy
weight. My Mercury weighs 3.78 pounds
including the supplemental button bracket.
Heavy paddling demands an instrument that
responds smoothly but doesn’t budge on the
operating surface under the pressure of a spir-
ited conversation or a fast-paced contest.
The Mercury uses two strong magnets
and two magnetic-metal attracting surfaces.
Each paddle stroke moves the magnet farther
away from the other surface, so its magnetic
force decreases through the stroke. Contact
spacing and magnetic attraction are adjusted
with coarse finger screws held into position
with locknuts. The adjustments are stable,
but fine tuning them can be tricky because
both finger screws and locknuts must be ma-
nipulated. The fingerpieces are installed at a
rather high fixed height ranging from 1.1 to
2 inches above the operating surface.
My Mercury is adjusted for light magnetic
return force and such a razor-thin gap that the
thinnest paper in my library cannot be in-
serted between its flat rhodium-plated silver