Frequently Asked Questions (FAQ) for Manual Variable Attenuators

1) Are all of the rotary attenuators break-before-make?

All JFW rotary attenuators are break-before-make unless otherwise noted on the specification sheet. JFW does manufacture make-before-break models, although none of them are currently in the catalog. Please contact sales with your requirements.

2) Does JFW have 100 Watt rotary attenuators?

The majority of JFW rotary attenuators are only specified to 2 Watts average. For higher power applications, we recommend using a high power fixed attenuator to decrease the power down to a level (2 Watts or less) that you can input into a rotary attenuator. This does increase your insertion loss, but it is the least costly way to manually attenuate a 100 Watt signal.

3) Are rotors available that increase attenuation when turning the knob counter-clockwise?

Yes, we just don’t have them in our catalog. The direction that attenuation increases (clockwise or counter-clockwise) is always listed on the specification sheet.

4) Are rotors available with custom step sizes (3 dB steps for example)?

Yes, we have designed and built many units that have non-standard step sizes. Please contact JFW at sales@jfwindustries.com with your specific requirement.

5) Are models available with mixed RF connectors?

Yes, you can mix and match whatever RF connectors are listed on the specification sheet.

6) How much does X dB of attenuation reduce the signal level by?

Attenuation	Power Reduction
1 dB	20.6%
2 dB	36.9%
3 dB	49.9%
4 dB	60.2%
5 dB	68.4%
6 dB	74.9%
10 dB	90.0%
20 dB	99.0%
30 dB	99.9%