User's Manual

Watertight Transmitter

Rio Rancho, NM

Re-conditioning (drying out) the caps and

desiccant beads

An easy way to heat the doors is to use a coffee mug

warmer, which typically costs about $10. The surface

temperature of about 220 degrees (F) will dry the

doors and desiccant, but it will not disturb any light

lubricant (like the Vaseline petroleum provided with

the WM) that is on the O-ring seals.

It is also possible to use the mug warmer to dry out the

doors without removing them from the case as shown

below. Do not place the transmitter on this heated

surface. Lay it to one side as shown.

The mug warmer used for testing consumed 17 watts,

so it could even be used on a sound cart AC supply

without being a huge drain on the batteries.

The color of the desiccant beads can be observed by

shining a pen light on one edge of the battery cap to

illuminate the desiccant. Ideally, they will be an amber/

orange color at room temperature.

Replacing the desiccant beads

When the beads remain darker green or blue, they

may not be absorbent any longer and should be re-

placed. Remove the screw that retains the spring and

vented cover with a small Phillips screwdriver.

While the cap assembly is apart and the beads re-

moved, the parts can be cleaned to remove dust and

corrosion. The best way to clean the parts is with pe-

troleum jelly (Vaseline). Apply the petroleum jelly and

then wipe the parts clean.

Vented cover

Do not use a silicone based oil or grease as it

will dissolve the O-rings.

Do not expose the desiccant beads to any

cleaning liquids or other materials.

Replace the beads with new, amber colored ones. Fill

the cavity to just below the top of the threaded stem

that holds the cover in place so that the cavity is full,

but the beads are not compressed when the vented

cover is replaced.

The desiccant beads are silica gel grade 52, manufac-

tured by a US Company named ADCOA under part

number SG52002. Large containers can be purchased

from ADCOA, and small quantities are available from

Lectrosonics. Contact Lectrosonics for details.