Tessaro Bellwether alt-az mount, head only

Specifications

Description

The Bellwether is a manual alt-azimuth mount for catadioptric telescopes and medium refractors, rated for payloads up to 12 kg. Its fork arms hold the tube on both sides of the head, so the telescope stays balanced as you move it. The mount turns in altitude, up and down, and in azimuth, side to side, so you aim it at the object you want to see and the head keeps the tube where you leave it.

Slow-motion rods on both axes allow fine corrections at high magnification, where a small hand movement shakes the image. Tension knobs set how freely each axis turns, so you can keep the head stiff for steady pointing or loosen it for quick sweeps across the sky. The 100 mm dovetail saddle accepts standard dovetail bars, and a safety screw holds the bar in place while you tighten the main clamp.

The head weighs 6.4 kg, so the Bellwether is best set on a sturdy tripod or pier. A telescope of about 150 mm aperture on a Maksutov or Schmidt-Cassegrain tube fits within the rated payload, but long tubes take longer to settle after you focus. As a rule, keep the total load, including a diagonal, eyepiece, and finder, well below the 12 kg rating.

The Bellwether has no motors and does not track the sky. Objects drift out of the field within a minute at high power, so you will need to nudge the tube by hand. The mount suits relaxed visual sessions at low and medium magnification, where a steady setup and simple controls matter more than automatic tracking.

About this configuration

Each configuration of the Tessaro Bellwether alt-az mount uses the same mount head; the options change what it stands on and what ships with it. This configuration is the mount head alone, so you supply a tripod or a pier with a matching top plate. Buying the head only makes sense when you already own a sturdy tripod or a permanent pier in the garden. This configuration ships without extra add-ons, so the box holds only the mount and its support.

Anodized red parts have the same corrosion resistance as the black finish, in a brighter color. The 2026 edition carries the mechanics over unchanged and updates small parts such as the knobs and covers. For steady views, keep the total load of tube, finder, and camera below the rated payload with some margin to spare.

What's in the box

• Alt-az fork mount head
• Two slow-motion control rods
• 100 mm dovetail saddle
• Accessory tray

Compatibility notes

• Accepts dovetail bars up to 100 mm wide.
• The 3/8-16 base thread fits most photo tripods; a 1/4-20 adapter is included.
• Suits telescopes up to about 150 mm aperture and 8 kg for steady views.