Re: Amplifier chain design - best practices
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?Spice it ...I did (using QUCS) .... Nearly a direct short to ground off the high impedance point of the amp (before the change) ...and you still have a linear control of the following amp chain (just checked it on my bench ...100 mV p/p in at head of LPF where it comes from the mixer to top of RV1 (3.0 V p-p) ...~30 db gain on modified Q90 circuit
Jim
On Friday, September 21, 2018, 10:25:26 AM PDT, ajparent1/KB1GMX <kb1gmx@...> wrote:
Jim,
Replacing RV1 with a 10K is not good as it would put all the adjustment in the last 5 degrees of rotation.
A 500 ohm may be better.
But you begging 1 db of gain increase for what reason?? ?Replace the 3904 in that stage prior and the
performance jumps a greater degree and fixes the actual problem there.
Allison
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