What is the typical resistance across the various terminals of a MC phono cartridge?

Applying DC across your cartridge is a big no-no and may well have damaged your cart (assuming you used a multimeter to try and measure the coil resistance)

Long discussion of this topic here in the context of some designs of demag circuits that may output DC
https://forum.audiogon.com/discussions/mc-cartridge-degaussing-demagnetizing

Having said this the current generated by a multimeter at the lowest resistance range measurement setting is probably <1mA, in other words in the same sort of range as that generated by the cart in use so you may be OK -- but don't make a habit of it

This thread piqued my curiosity sufficiently to prompt me to make a measurement, using the two multimeters I have. One is a very high quality Fluke 87V digital multimeter, which can measure extremely small amounts of current. The other is a Triplett 310 analog multimeter. I set the Triplett to the Rx1 scale and used the Fluke to measure the current the Triplett provided with the lead of each meter connected directly to the corresponding lead of the other meter.

The Fluke indicated a current of about 7 ma, with the Triplett indicating a load resistance of close to zero ohms.

When I tried going in the other direction (using the Triplett to measure the current provided by the Fluke with the Fluke set to measure resistance), the Triplett presented too much resistance to allow a meaningful measurement to be taken.

A low output moving coil cartridge putting out 0.5 millivolts, a typical number for many LOMCs under the standard test conditions, and loaded with say 100 ohms, would be supplying and conducting a current of 0.5 mv/100 ohms = 0.005 ma, vastly less than the amount of current the Triplett meter supplied when measuring a near zero resistance. And the fact that a meter applies DC while the cartridge generates and conducts AC during normal operation may add to the possibility of damage.

The bottom line would seem to be what Folkfreak said above and what I initially suspected, that using a multimeter to measure the resistance of an LOMC is a no-no.

Regards,
-- Al

@almarg that seems a high current level, I was drawing on the specs as posted here ... of course we both agree it’s not something you should do. Am I stupid to presume that applying current at these levels to an MC would actually cause the cantilever to deflect (ie turning the generator into a motor?)
http://www.ni.com/tutorial/3981/en/

Hi Folkfreak,

Thanks for providing the reference on the National Instruments meter. At a list price of $2674 that of course is a very different animal than the meters most of us have, but the 0.95 ma of current it provides on its two lowest resistance scales is still far higher than the current a typical LOMC would normally generate and conduct.

And yes, I’d imagine that cantilever deflection in response to such an applied current might indeed be a problem.

Best regards,
-- Al

Thank you all for the responses.
I had been chasing the source of an annoying little hum and ended up back at the cartridge. Admittedly I'm nitpicking but even a tiny hum can be annoying. My multimeter is of the older analog scale type and generally I use it as yes or no when it comes to ohms. I noticed that the cartridge has an open circuit between ALL of the different terminals (really sounds great except between songs). As I had a nearly new dl-103 I measured that as well, completely different measurements, what I expected would be correct. Nothingness between the positives. Perhaps this humming cartridge is supposed to have an open circuit between the positives though this seems really unlikely as it's a dl-103r (rebuilt canti etc) so probably pretty similar. Regardless, it needs to be looked at.

Long story short (no pun intended), installing the stock 103 fixed the problem and seems to have sustained no damage from the abuse.

Thankfully these are relatively inexpensive cartridges but I will certainly refrain from such measurements in the future. 

Kind regards,
Mark