An arrangement for accurately measuring the frequency of an RF signal is disclosed. The arrangement includes a coaxial delay line carrying the RF signal and a means for directly measuring the resistance of the coaxial delay line and which resistance measurement is directly correlatable to temperature changes of the coaxial delay line. The arrangement, in response to the changes in the temperature of the coaxial delay line, provides appropriate signals to compensate for the temperature changes in order to prevent any temperature changes from degrading the accuracy of the frequency measured by the arrangement.