Page 23 - iSEMconCatalog

The Roof Top comes with anti-bird spikes packaged OPS35 Heater
separately but not inserted. These can be installed by
the customer if needed.

Roof top Diameter 150 mm

The OPS35 heater is an easy to use as well as
economical way to protect a microphone diaphragm
from condensing water. Condensation changes
frequency response behavior while adding weight to
the microphone diaphragm. The use of a chemical type
dehumidifier is limited in time of use. Such a
The fabric used is water tight but acoustically t dehumidifier requires monitoring as well as drying if
ransparent as far as possible (not rubber coated). The saturated from humidity.
fibers become water tight upon getting wet (ref. tent
cloth). It can be removed for cleaning, replacement The heater is 100% reliable and is maintenance free.
and/or impregnation.
The OPS heater uses a special heater element which is
fail safe. The colder it is, the more heat the
OPS35-MHTptc adds. It will not add heat at high
temperatures and overheating is not possible.

The following graphs show you the heater performance
characteristics. Temperatures have been measured at
the mic capsule position (acoustical port) of an installed
microphone (1/4” type).
For comparison the “no heating” graph has been added
as well. It shows the mic capsule temperature following
the ambient temperature 1:1.
The red graph shows the mic capsule temp with the
heater installed and powered from 12Vdc. Do not
power from 12Vac due to possible crosstalk (hum) with
microphone installed or microphone cable used.

Ordering information :
Order No. Name
500060 OPS35-MHT ptc-1/4

500061 OPS35-MHT-imp 1/2
500062 OPS35-MHT-iec 1/2

500040 OPS35-RT150

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