"John Larkin" wrote in message
...
On Tue, 17 Jul 2007 23:22:41 -0500, "Tim Williams"
wrote:
Monitor V, I (or control one and watch the other) and sweep frequency; find
series resonance, ESR, ESL and C in one pass.
That is close to a mini VNA. That actually might not be hard to do.
DDS synthesizers are cheap nowadays.

A single port VNA, yes. See, e.g., http://w5big.com/index.htm . Goes down to
100kHz, which should be reasonable for measuring ESR.

---Joel