50 Ohm
Buffer-Distribution Amplifier
.by by Steve Smith,
G8LMX
50 ohm Distribution Amplifier
This 50 ohm distribution amplifier is
capable of producing three outputs of 1 volt RMS from an input of
0.5 volt to 1 volt RMS. The boards can be daisy chained together on
the input with the terminator on the last board.
Obviously if input requirements are different,
the R1 / VR1 combination would need adjusting.
I designed the
circuit around the MAX477 chip
as it has a unity gain bandwidth of 300MHz, high output drive
capability, and is relatively inexpensive.
Note
that resistor R4 should remain about 470 ohm if the gain of the
circuit is changed. Also, the outputs are not ground isolated. Apart from that it is fairly simple and self
explanatory.
Circuit Schematic
Component Layout Drawing
Printed Circuit Layout
Photograph of the
amplifier board in a Rubidium standard constructed inside an old HP
counter case.
2003 Steve Smith,
G8LMX
