Nokta SX28 11 in Waterproof DD Search Coil for Simplex LITE, ULTRA, BT and FINDX Pro

The Nokta SX28 is an 11 in (28 cm) waterproof Double-D (DD) search coil for the Nokta Simplex LITE, Simplex ULTRA, Simplex BT and FINDX Pro. It is the coil that ships as standard on the Simplex ULTRA and the FINDX Pro, so owners of those detectors buy it as a spare or a replacement. On the Simplex LITE, which ships with the smaller SX24 9.5 x 6 in coil, the SX28 is the step up for wider coverage on open ground. It comes with a coil cover and mounting hardware.

Who the Nokta SX28 coil is for

• Simplex LITE owners: the SX28 is the main upgrade from the stock SX24. The 11 in footprint covers more ground per swing in fields, parks and beaches where targets are spread out. Nokta also sells the Simplex LITE as a package with the SX28 fitted.
• Simplex ULTRA and FINDX Pro owners: your detector already came with an SX28. Buy this one to replace a cracked, worn or lost coil, or to keep a spare for trips.
• Simplex BT owners: the Simplex BT is discontinued, and Nokta no longer lists it on the SX28 page. The SX28 was built for the Simplex platform the BT belongs to, so BT owners can use this coil as a replacement.

If you hunt trashy parks or old homesites full of nails, a smaller coil separates targets better than the SX28. The SX24 9.5 x 6 in is the compact option for the same detectors. For big open fields where coverage matters most, the SX35 13.5 x 12.5 in is the largest. All three are in our metal detector search coils collection.

Key features of the Nokta SX28

• 11 in round footprint: covers more ground per swing than the SX24, so you need fewer passes on a large site.
• Double-D (DD) winding: a DD coil handles mineralized soil with fewer false signals than a concentric coil of the same size, which keeps target IDs steadier on iron-rich ground and wet salt sand.
• Waterproof construction: the coil goes into streams, surf and wet sand with the detector.
• Open-frame design: the open center keeps weight down and lets water and sand pass through as you swing.
• Cover and hardware included: the coil cover protects the shell from rocks and abrasive sand from the first hunt, and the mounting hardware fits it to the lower shaft.

What is in the box

• Nokta SX28 11 in waterproof DD search coil (part 17000179)
• SX28 coil cover
• Coil mounting hardware

Replacement SX28 covers (part 17000263) and 28R mounting hardware are also sold separately.

Nokta SX28 compatibility

Fits:

• Nokta Simplex LITE (upgrade from the stock SX24)
• Nokta Simplex ULTRA (standard coil, all versions)
• Nokta FINDX Pro (standard coil)
• Nokta Simplex BT (discontinued)

Does not fit:

• The original Nokta FINDX, which uses its own FX28 11 in coil. The FX28 and SX28 are not interchangeable even though both are 11 in.
• Nokta Simplex+, which Nokta does not list for the SX28.
• The Nokta Legend and Legend 2, which use LG and LD series coils.
• The Nokta Score series, which uses SC series coils.

The SX28 plugs into the detector's coil connector and mounts on the standard lower shaft. No settings change is needed after you swap coils, but run a fresh ground balance when you start detecting.

Where the SX28 works well, and where it does not

• Open fields, sports fields and beaches: this is the SX28's strength. The 11 in footprint covers ground quickly, which matters on plowed relic fields and during low-tide windows on the beach.
• Wet sand and shallow water: the coil is waterproof. The Simplex LITE, Simplex ULTRA and FINDX Pro are rated IP68 and submersible to 16 ft (5 m), but Nokta does not publish a separate depth rating for the coil. We've used the SX28 in wet conditions without issue. Rinse the coil and connector in fresh water after salt use.
• Mineralized ground: the DD design keeps the SX28 more stable than a concentric coil on red clay and iron-rich soil. Heavy black sand is still difficult for any single-frequency detector, including the 15 kHz Simplex models.
• Trashy sites: in nail-filled homesites, busy tot lots or along fence lines, the 11 in footprint can read a coin and a nearby piece of iron as one signal. The SX24 is the better choice there.
• Brush and tight spots: the SX24's smaller elliptical shape gets between roots and rocks that the SX28 cannot reach.

Nokta SX28 compared with the SX24 and SX35

SX24 (9.5 x 6 in): the stock coil on the Simplex LITE. It separates targets better in trash and fits into tight spaces, but covers less ground per swing than the SX28.

SX35 (13.5 x 12.5 in): the largest coil for these detectors. It covers more ground per swing than the SX28 on open fields and beaches, but it is heavier at the end of the shaft and the hardest of the three to use around trash and brush.

The SX28 sits between them, which is why