Bob Cordell Interview: Error Correction

Hello Everyone,

I've read almost whole thread and found it very inspiring. Unfortunately plenty of links in posts are now dead. I would be grateful if one can confirm my reasoning of balance equation.

Let's assume circut as in original Hawksford paper (attached, T2 collector connection is wrong, right?).
Considering just an upper half of the circut.

Vin = V(T3emitter | T5base)
and let assume Vout= 0

Then:

V(T1base) = Vin * [R4 / (R3 + R4)]
R2 - can be seen as emitter degeneration resistor, so T1 gain in G(T1) = ~ R1 / R2

let [R4 / (R3 + R4)] = k,

if balance is for G = 1, then V(R1) = Vin, and V(T1emitter) = Vin

-(Vin * k - Vin) * R1 / R2 = Vin
-Vin * (k - 1) * R1 / R2 = Vin
-(k - 1) * R1 / R2 = 1
(1 - k) * R1 = R2

Hawksford.png


Thanks to anyone, who can review my analysis, and point if I miss something, or even whole point.