I've been trying to restore an old HP400D Vacuum Tube Voltage Meter. Section 5-20(f) in the manual says:
Measure the direct current in the lead from V7 (pin 1) which must be less than 60mA... Excessive current indicates a short or partial short in the circuits of the voltmeter amplifier section. A clip-on type milliammeter should be used for this measurement.
Presumably, the manual is saying to use something like the HP Model 428B. Unfortunately, I don't have one. Therefore, I am wondering if there is another way to measure the DC current without having to cut the wire. Since I'm only testing for a short (or near-short), and the expected current is very small, I don't think need an extremely accurate measurement. Any ideas?