Retrofit Your Meade ETX-125, ETX-105, or ETX-90 Telescope
Create custom telescope solutions by replacing the black plastic back on your ETX telescope with your own creations.
These black hard anodized aluminum adapters were designed for the Meade ETX-125, ETX-105, and most ETX-90 optical tube assemblies manufactured prior to the Meade ETX Observer Series released in 2017.
- The ETX-125 OTA Adapter is threaded for 2 inch Schmidt-Cassegrain telescope accessories
- The ETX-105 OTA Adapter is threaded for 2 inch Schmidt-Cassegrain telescope accessories
- The ETX-90 OTA Adapter is threaded for standard 1.37 inch (34.6 mm) ETX telescope accessories
Fitting a Wegat adapter
By removing the focus knob, black plastic back, and fork mount from the OTA, a Wegat Optical adapter attaches to Meade ETX-125, ETX-105, and most ETX-90 tubes manufactured before the Observer Series.
- Remove the focus knob from the focus shaft.
- Separate the optical tube from the fork mount (if still attached).
- Remove the black plastic rear cell / back from the tube.
- Seat the Wegat Optical adapter and fasten it with the kit screws; install the access-hole plugs as supplied.
- Cap the threaded port with the included end cap when not using accessories.
Mounting the OTA
After the plastic back and fork come off, the optical tube still needs a way onto a mount. Owners of Wegat-converted ETX-125, ETX-105, and ETX-90 tubes usually use one of these approaches:
- Vixen-style dovetail on the tube — Most ETX-90 / 105 / 125 OTAs have two ¼-20 holes on the bottom mounting block. A low-profile dovetail (for example ScopeStuff’s ETX dovetail bar) bolts there and drops onto a Vixen saddle. ScopeStuff ETX dovetail review (Weasner)
- Tube rings + dovetail — Exact-fit rings are uncommon. ETX-125 tubes are about 5.75″ (146–147 mm); people use Parallax 5.75″ rings made for the 125, or slightly oversized rings (ScopeStuff / ADM and similar) with felt or foam. ETX-105 tubes are about 125 mm and fit mid-size adjustable rings on a Vixen or Losmandy plate. See Tube rings for an ETX125? (Cloudy Nights) and examples in our Gallery.
- Custom plates and builds — Home-machined adapters, binocular mounts, and one-off EQ fittings show up in the same forums and in the Gallery.
Some ETX bottom holes arrive plugged and need clearing. A rear diagonal on a Wegat back is the usual way to keep the eyepiece usable on a German equatorial or alt-az mount.
Discussed online:
- Wegat backs for ETX-105s (Cloudy Nights)
- Wegat Optical back on an ETX-105 (Cloudy Nights)
- The single best mod — ETX-125 (Cloudy Nights)
- ETX-90 Wegat conversion (Cloudy Nights)
- @WegatOptical on X
See the adapters in use:
