[R-390] Re: R-390 Resistor Tolerances

[Roy Morgan]

At 01:26 PM 7/30/02 -0400, Drew wrote:
>Hello All,
>
>An observation about the effect of resistor tolerances in the R-390 series:
>The value of many resistors in the IF deck could vary over a wide range 
>with little practical effect.  Screen and cathode resistor variation would 
>have an effect on gain but remember that the potential IF gain is much 
>higher than necessary or desireable.
>
>When all is said and done, we simply adjust the IF Gain control far below 
>maximum thereby obtaining best noise figure.


BUT....

If you increase the IF gain to compensate for one low-gain RF stage, or one 
low-gain IF stage, you are disturbing the gain distribution of the radio as 
a whole and, under certain circumstances, the thing will perform less well 
than if you'd fixed that low-gain stage properly.

I agree with you that this condition will bring little practical effect though.

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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