Question 6A220

While some microphone types are inherently high impedance, others are not. However, in amateur radio, any microphone type can be made to present a high impedance output. Crystal microphones naturally have a very high output impedance. Dynamic microphones, on the other hand, typically have a low output impedance. However, a common practice in amateur radio, especially when interfacing modern low-impedance microphones with older equipment designed for high-impedance inputs (like many tube-type transceivers), is to use an impedance matching transformer or a preamplifier. These devices convert the microphone's native impedance to the desired high impedance, effectively allowing *any* microphone to "have" a high impedance output as presented to the radio.