[TenTec] Jupiter Solid Aluminum Main Tuning Dial

[David Goncalves]

Just to waste some time at work, I pulled up the manual for the Jupiter. The
Encoder is just listed as 'HRPG Encoder' with no further infomation. When
searched in google, I pulled up a datasheet from Agavo, which seems to be
the spin-off of HP/Agilent. For the common type Agavo makes, they have a
maximum radial load of 0.1 N-m. If I understand the specification correctly,
radial loading is the 'cantilevering' I was talking about, and axial loading
is INTO the encoder along the axis of the shaft. Perhaps I'm wrong. But if
I'm not, and the encoder has a shaft length of ~1.27 cm, and the center of
mass of the knob is also the geometric center and that point is about the
midway point of the shaft, then 0.1 N-m / .0127 m  / 2 = 3.93 N ~ 400g. Hope
that's right. A Jupiter knob looks like 4.5 cm diameter, 1.5 cm thick,
density of aluminum is 2.7 g/cm3, making an aluminum knob ~65
grams. Assuming all that was close to right, then it seems that putting in
an aluminum knob would be OK.

David Goncalves
W1EUJ