Abstract: An apparatus for concealing wires in a riser of a motorcycle comprising a throughbore extending along a length of the riser thereby forming a first channel therein. A handlebar includes a second channel extending therethrough and an egress aperture extending through the second channel aligned with a first end of the throughbore. A bolt having a bolt channel extending therethough is received within a second end of the throughbore for securing the riser to a wheel guard. Wires connecting at least two electronic components are received within the second channel and extend further through the egress aperture and through the throughbore and further out from the bolt channel thereby concealing the wires within the handlebars and the riser.

Abstract: An estimator for estimating an operating defect in a quadrature modulator, including two mixers to which respective carrier signals are applied, and to which respective modulating signals are also applied. The output signals from the mixers are applied to a summing circuit so as to constitute a modulated signal. The estimator includes detection circuitry for detecting the instantaneous power of said modulated signal; multiplication circuitry for multiplying the detected instantaneous power by at least one of the modulating signals; and integration circuitry for integrating the result of the multiplication and for supplying a signal indicative of the operating defect of the modulator. The modulator is particularly applicable to removing the residual amount of the carrier signals that remains in the modulated signal, and to correcting the quadrature between the signals output by the mixers.