Tek SG505 Opt2 (Bal) schematics?

[Zero Cool]

I am looking for schematics for the Tektronix SG505 Option2, the balanced output option.

I have schematics for the standard 505 and I am wondering how they are doing the balancing. and more specifically how the output on the rear connector is done? On the unbal 505 they use pins 25 and 26 but I'm wondering if the balanced version outputs a balanced rear output. or is in unbalanced, and if it is unbalanced is it at the same gain as the balanced output??


Zc

[dinos8746]

They convert the unbalanced to balanced with an inverting stage. It outputs a balanced signal thru the 25A (+) and 26A (-). The rear balanced signal comes from two LF353, with -20db attenuation of the front signal and 600ohm output impedance (300 ohm in each rail).

[dchisholm]

Originally Posted by dinos8746

They convert the unbalanced to balanced with an inverting stage . . . .

Is that the same circuit used in Jim Williams' "Ultra-Pure Oscillator" (except that he created a 100 ohm balanced output, rather than 600 ohms)? See atch; taken from Fig 96 (pg 65) of Linear Technology AN67.

Dale