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Tuning Instructions Number 025790 Rev: 1 Date: August 5, 2010
Isolators/ Circulators
Installation and Tuning Instructions
When used as isolators, both single and dual models are available with a variety of load
terminations for the isolated ports. Retuning of these units may be performed in the field
in the 2-4 MHz bandwidth by following the instructions below.
These units can be retuned within this bandwidth specification by adjusting the tuning
capacitors located at the front and rear of the units. Retuning beyond the bandwidth
specification is not recommended in the field as this may require a re-adjustment of
magnets located internally to the units.
VSWR: In/Out (all units) (23 dB+) 1.25:1 max
Note:
Ferrite isolators are subject to certain non linearities and may conduct or generate a weak signal harmonic.
For proper IM protection, a low pass 2
nd
harmonic filter is often used between the isolator and antenna to
suppress the 2
nd
and 3
rd
harmonic energy of the transmitter. The Sinclair AF series of 2
nd
harmonic filters
are available for this purpose.
Single Stage Circulator
Dual Stage Circulator
Table 1: Electrical Specifications
