IsoTennuator and UnBias-Tee — Accessories for GUS


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SKU: GUS-ISOTEN Categories: ,


The TAPR IsoTennuator is an RF attenuator that works when there is DC voltage on the signal path.  Regular attenuators provide a DC path to ground, so will dissipate power if voltage is present.  The IsoTennuator provides a DC path around the attenuator components to allow attenuation while still allowing the cable to carry power for a remote amplifier.

The IsoTennuator’s inspiration was the desire to attenuate the signal from a GNSS antenna going in to a GUS GNSS antenna splitter to compensate for the GUS’s  8 dB gain.  In some cases that gain isn’t wanted and the IsoTennuator may be placed at the GUS antenna input to remove it.

The UnBias-Tee is simply a DC blocking capacitor with LEDs to indicate if DC is present at either of its connectors.  It’s useful mainly for troubleshooting antenna feed systems.

This kit includes IsoTennuators with 3 dB, 8 dB, and 15 dB attenuation and one Unbias-Tee.  All SMT parts are assembled; the SMA connectors are soldered by the user. We provide one male and one female SMA connector for each of the four boards in this kit (a total of 4 each, male and female.) We use SuperBatRF SMA connectors: male part number: S01-SPEDM-11BS05, female part number S01-SJEDM-11BS05.

NOTE: The IsoTennuator is not a precision attenuator and should not be used for measurements.  Its attenuation may be +/- 0.75 dB and its performance has not been checked outside the 1 — 2 GHz range.

The user guide for the IsoTennuator and UnBias Tee is available here.

Additional information

Weight 2 oz
Dimensions 2 × 3 × 1 in


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