Mike Silva wrote:
Duncan Munro wrote in message
. ..

The metal film 33R measures 6.5uH and the oxide 22R measures 4.5uH on the
aade.com meter. Both values (if the readings are correct) would represent
a high ratio of X to R at HF frequencies...

I wonder, though, if the AADE meter is not getting confused by the
resistance of the resistor. The fact that the measured inductance is
just about proportional to the resistance might be evidence for that.

Duncan has kindly sent a couple of samples, with duplicates that have
had the paint scraped off. I just arrived home from a few days away, so
haven't had time to measure them yet.

Each one is only an open spiral of about two turns along the whole
length of the 3W resistor body, so you can see immediately that there's
no way the inductance can actually be more than a few hundred nH.

This actual, physical inductance is in *series* with the resistance.
What seems to be happening is that the AADE meter displays the
resistance and reactance in their equivalent parallel form, which is a
function of the measurement frequency (which varies, but is understood
to be in the order of a few MHz).

Guessing a frequency and then doing the parallel - series
transformation on 22 ohms in parallel with 4.5uH produces results in the
right ballpark: R is still around 22 ohms but the *series* inductance is
100-200nH.

I will try to measure the resistors tomorrow.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek