VTVM/Analog VM/DMM Input impedance?
 

Have a question relating to input impedance on these badboys. Hope someone can explain this to me :)

So far I've learned that VTVMs typically have an input impedance around 11 Megohms, and that DMMs won't give accurate readings on tube gear because they have different impedances (e.g. my cheapo has 1megohm input impedance). I'm just talking about general use on vintage gear, e.g. peaking a coil at a certain frequency, not just taking voltage measurements.

I found a 70s era analog meter amongst my things (russian Moskow C-4313) and it has specs for an input impedance of 2000 ohms/volt AC. (20Kohm/V DC)
My question: Is that far too low for use as a peaking meter, or is that multiplied by circuit voltage to get correct impedance? (If not, I assume the other sites mentioning 11megohms meant 11 megs/volt but left off the per volts part?) Am I just way out in left field overthinking this?


Can a standard analog meter be repurposed as a crude peaking meter by adding a resistor to the probe (and calculating the appropriate voltage for the divider that results- though that's not really an issue when peaking, only when taking absolute measurements)

2000 Ohms per Volt is not good. That means on a 100 V range it will be 200K Ohms, not high at all. To say it another way, it draws 1/2 mA at full scale.

The answer to your last question is yes. For peaking, almost anything will work in most cases.

Thanks for the reply.

I found some additional information (and coupled with your reply) I understand it better now and the difference between overall impedance and impedance per volt.