Rai Weiss designed a low noise FET input amp using the IF3602.pdf which should have an input voltage noise of 0.3 nV/rHz.
Josh Myers (of LHO) made a PCB version of it (D060205-A).
It is basically a differential amplifier made up of the IF3602 dual-FET followed by a LT1128. It has 9V batteries for power.
We want to make a newer, better version of this preamp.
Notes on the New Version
- Use panel mount BNC, not board mount.
- LED indicator of battery health should be a temporary 'Batt Test' switch, not an always on.
- Need an alternate input for power (e.g. Banana from the SR560, or the 3-pin D of LIGO standards).
- Needs voltage regulators inside for the power input.
- Metal film resistors. For the 5 Ohm resistors, we just parallel some 10 Ohm ones.