Identifying Test Equipment from Revox Service Specs

[TinkerGDS]

I am an electronics hobbyist and love to work on vintage stereo equipment.  One of the components I like to work on is Revox equipment.  It is beautifully built and the service manuals are very well written.  I can diagnose circuits, test and replace capacitors and some of the other more rudimentary tasks, like checking for broken solder joints.

Now I want to take my electronics adventures to the next level and start actually aligning or calibrating the components I'm working on.  I'm having a difficult time understanding some of the test equipment requirements.  They ask for AF Generator (which I'm assuming is an arbitrary function generator, I could be wrong), an AF voltmeter (never heard of one of those), an digital voltmeter (I think I have that covered, but not at the millivolt level), Variable Ratio transformer-variac, RF voltmeter, and stereo demodulator.

There is more test equipment listed, and I think I have those covered:
o-scope (Tek 2645B)
function generator with sweep (HP 8662A and Siglent 2122X
frequency counter (Siglent 2122X and HP Spectrum analyzer 8568B)
two Siglent Bench Multimeters (SDM3055)
and Fluke 289 multimeter

Any advice or direction is greatly appreciated.

[nctnico]

AF=Audio Frequency. In other words: equipment usefull between say 1Hz to 20kHz with reasonable accuracy.

[TinkerGDS]

Thank you.  That makes sense.  So the 8662 is out.  The Siglent has a frequency span of 1uHz to 120MHz so that'll work.