[Boatanchors] how to read microvolts

[Dick KF4NS]

This may be a dumb question but I really cannot find a way to read 
microvolts of RF.  My old Heath RF sig gen has bad resistors in the 
attenuator but I only know that by reading the values of the 
resistors.  What can I use to read the output of the sig gen in very 
small values of microvolts?

My scope will not read that low and my VTVM with RF probe will not 
read it either. I can read millivolts on various pieces of my test 
equipment but the only thing I can think of is to boost the signal 
with an amp and then allow for the difference as long as I can be sure 
of the total gain of the amp.

Please enlighten me.
Thanks and 73, Dick KF4NS
St Petersburg, FL 33714 USA
Keep The Glow!