[R-390] Filter test setup

[quartz55]

It was not very effective using the service monitor as both the scope (detector) and generator, so I incorporated the RF milivoltmeter as the detector. So, to establish a base line, feeding the 50 ohms out of the SM to a .1uF for DC block, 100K ohms for series impedance matching for the filter, and loading the output of the filter with 100Kohms as in the picture.

First, I tested the output of the SM into the VM with a 50ohm adapter and the VM agrees with the SM within 2db, in 10 db steps also all the way to the bottom VM scale.

Removed the 50 ohm adapter, VM clip lead to the output side of the 100K ohm series resistor, and stepping through 10 db out on the SM, I get only a few db difference on the VM, it takes about 20 db of SM output attenuation to reach a point of 10db steps agreement from the SM to the VM.  I attribute this to impedance variations at the high levels???