How are transformer attenuators different from resistor based attenuators?
Resistive attenuators such as stepped attenuators and potentiometers work by converting voltage and current into heat. In transformer attenuation, the transformer works more like a gearbox. The voltage amplitude is converted on a ratio to the turns from the primary to the secondary. Barring small copper losses* in the transformer, this conversion does not affect current. * Resistance of the copper wire in the transformer.
