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08 January 2011
December and January have been the busiest months at
Clifton Laboratories yet and it has not left much time to maintain this web site
and to expand my investigations into the world of electronics.
One of the things that has kept me busy is the Z10043A,
"mini-Norton amplifier" which is a physically small Norton amplifier, usable
from 100 KHz to 30 MHz, pictured below.
The amplifier is 2.5 inches x 2.0 inches and 0.75 inches
thick. (Some components are mounted on the PCB's lower surface, and the total
thickness is 0.75 inches.)
The Z10043A will be available for order within the next
few days. At the moment, I'm completing the assembly and operations manual and
hope to have it posted tomorrow.
The Z10043A is the best and most consistent performing
Norton amplifier I've built. One measure of the consistency is that bias
adjustment potentiometers are not required. In addition, input and output
transformers are commercial units from Mini-Circuits. The feedback transformers
are wound on binocular cores, which is considerably easier than toroid cores in
other Clifton Laboratories Norton amplifiers.
I've built 4 of these amplifiers and found OIP3 between
+49 and +51 dBm and OIP2 between +90 and +110 dBm with a noise figure of 2 dB.
It is possible to achieve a noise figure of approximately
1.4 dB with component changes to reduce the idle current in Q1 and Q2, but there
is considerable degradation in OIP2 and OIP3.
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