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Old October 20th 05, 06:29 AM
 
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Default Shunt feedback in broadband RF amps

Allison: Thanks.

Obviously you are right. But I see the same kind of confusing language
in other editions of the handbook. In the 1980 edition (otherwise one
of my favorites) they have (pg 6-19) a collector-base feedback network
with just a cap and a resistor in series. Text reads: "C1 and R3
provide negative feedback which increases progressively as the
frequency is lowered." It calls for a cap of values between 220 pf and
..00015 for hf band amps, IN SERIES with a resistor of from 51 to 5600
ohms.

Is this just a case of some confusing language that has kind of worked
its way in the handbook DNA and is passed down from generation to
generation? Or is there really something about these cap and resistor
in series networks that cause them to increase the amount of feedback
as freq drops?

73 Bill M0HBR N2CQR CU2JL
http://www.qsl.net/n2cqr