[sdiy] A little OT, Begging a hand

[Ian Fritz]

Hi --

I'm pretty sure your problem is underdetermined. Here's my reasoning:

The problem has four independent variables, if I understand it 
correctly.  Take the delta in the circuit and convert it into a wye 
(pictorially).  You now have a wye with series resistors in each arm.  You 
may add the series resistors together. Now you have a wye with three 
unknown resistors connected to V1, V2 and V0, plus a known resistor 
connected from V0 to V3.

So now you see that your system is equivalent to a circuit with only three 
unknowns.  Thus whatever measurements you make the best you can do is to 
determine three combinations of your four unknown resistances.

Ian