Voltage regulators on left and right side of the board, with pads
Additional filter-cap for each output-stage, to tune gain-peaking
and bandwidth of each stage (unexplored so far)
Front panel LEDs indicating presence of +6V and -6V rails.
2017.07 S/N 5, phase-noise measurement
The residual phase noise of the amplifier was evaluated with a
Microsemi/Symmetricom 3120A phase-meter. A 10MHz source was split
(MiniCircuits ZFSC-2-1+) into REF and DUT signals. When adding the
FDA2017.07 into the DUT signal-path a residual phase-noise of ca -162
dBc/Hz at >100 Hz offset from a 10 MHz carrier was observed. Close-in
phase-noise and AM noise is limited by the instrument noise floor in
close to the current version, but with both voltage regulators on the
same side of the
Surface-mount version of the TADD-1 distribution amplifier using AD8055
op-amps. This design reached a phase-noise of <-155 dBc/Hz at >1 kHz
offset from a 10 MHz carrier.