[mike_z]

The Peak Atlas LCR 45 is an impedance meter. It will measure capacitance, inductance and resistance. It will also measure an impedance that is reflected through a transformer. So..... with the speaker connected to the audio output transformer I can measure the load the output tube would see by connecting the LCR meter to the primary of the audio transformer. Usually this works, but this time I didn't get the impedance that matched the 42 datasheet. I may have made a mistake either with the setup or reading the datasheet, but the speaker hums when the signal generator is connected. I measured the impedance of the speaker as 1.22 ohms DC and 23.7 uH. Mike