09-24-2021, 03:27 PM
Remember, no broadcast stations have a frequency response greater than 5 khz today. The only way to enjoy the 9+khz bandwidth is to broadcast your own signal. I do that and the sound is remarkable for a 1938 radio.
It is possible to manually tune to the exact frequency of the broadcast station. Then, when the MT is engaged, it should not change the local oscillator frequency and there will be no change in how the signal sounds. However, if the MT is not aligned properly, turning on the MT will actually pull the oscillator off from the proper frequency resulting in a slightly detuned station and the sound will be affected, same as it is if you manually detune the station with the MT off. It is possible to use this fact to align the MT, adjusting the MT transformer for no tonal change when switching the MT on and off. In general though, better to use a signal generator and a meter to monitor output.
It is possible to manually tune to the exact frequency of the broadcast station. Then, when the MT is engaged, it should not change the local oscillator frequency and there will be no change in how the signal sounds. However, if the MT is not aligned properly, turning on the MT will actually pull the oscillator off from the proper frequency resulting in a slightly detuned station and the sound will be affected, same as it is if you manually detune the station with the MT off. It is possible to use this fact to align the MT, adjusting the MT transformer for no tonal change when switching the MT on and off. In general though, better to use a signal generator and a meter to monitor output.