Tektronix AA5001 calibration and repair

Tektronix AA5001 Audio analyzer plug-in

The Tektronix AA5001 is an audio analyzer plug-in for the TM5000 system. Being the newer version of the AA501, it provides essentially the same features in the same package, adding GPIB programmability.

It is intended to be used in conjunction with the SG5010.

The DA4084 is a modified variant of the AA5001 that replaces IM measurement with a SINAD function for radio equipment maintenance and characterization. The THD+N measurement of the regular AA5001 fails to measure signals with more than 30% noise content accurately because the autotuning of the notch filter will fail at these high noise levels. The SINAD function in the DA4084 performs the same measurement as THD+N but uses additional circuitry to lock the internal notch filter onto the audio tone at a low noise signal, and then maintains this lock for high noise signals up to 50%, which is sufficient for normal SINAD testing to find radio receivers’ sensitivity levels. The DA4084 features an ‘UNLK’ indicator that illuminates when the lock to the fundamental signal is lost.

The DA4084 was supplied in a modified TM5003 rack with an unusable left slot and a linear regulating power supply, but also works in generic TM5000 mainframes. The Army designation for this combination (DA4084 and special power supply) is TS-4084/G.

Key Specifications