Replacing the desiccant beads – Lectrosonics WM - Manual User Manual
Page 19
Watertight Transmitter
Rio Rancho, NM
19
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 replaced.
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 petro-
leum 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.