Mystery Vintage Wirewound Voltage / Wattage

[Elvee]

I could not measure any inductance in the 330k value I have.

With my examples their tolerance is better than .1% with a .5% marked tolerance.

Which is not to discount your experience, but to suggest that maybe this is a higher quality example than you may have been most familiar with.

Equally possible is that I am luckier than you ;-)

You don't need a sophisticated impedance or inductance-meter: just build a voltage divider, like 100:1 with the RUT being one of the arm, and the other a "golden standard" (a carbon film resistor in fact, or metal film if you have expensive tastes).
If the RUT is of a low value (~<1K), use it in the foot of the divider, otherwise use at the top.
Inject a squarewave of a suitable frequency and observe the result.
Here is an example of you could see: the self inductance resonates with the self capacitance, leading to overshoot and ringing.
The result is highly variable, depending on the resistor's construction and value

 

[snax]

I know, breathing life into a dead thread... but I also bought these resistors, 330K, to put into a tube preamp. THEN I found this thread but still little information so I thought i would share.

Pics of inductance @ 619mH... and a seriously old Radio-Craft-1933 advert for said design, not suggesting that they were made at this time but were around at this time.