Hickok 534B.

The 534A and 534B are almost identical. The B has some small changes in the circuit diagram, functions are the same. They are 533 with a build-in multi meter, so for the basic functions we refer to the 533. This tester has also a "remaining life time" switch, which allows a special test. So you have Transconductance, the Emission Test on the "good/bad" scale, and the "remaining life time" test.

Please note this for the multi meter: It is fully separated from the tube tester, only uses the same meter. These multi meters are normally working, but they have several carbon resistors in it, which simply can nto be in calibration any more. The multimeter is build on a separate panel, and is actually a very nice thing, and well build. It can do AC and DC, up to very high voltage, capacitance, power supply chokes, and Electrolytic capacitor leakage current under high voltage. It works with tube diodes, which for rectification of small signal are better than solid state diodes. Ohms measurement it can do 100 Meg ohm, since it does so with higher voltage. The resistance measurement works with a current source, so when you connect the probes, it goes to zero, and if you leave the probes open it gives a full scale reading.