Thanks Will,
One quick follow up:
Can the RF gain of a stage be inductor collector and capacitor emmiter
biased transistor be changed by varying the capacitor value?
Thanks - Dan
Will Matney wrote:
>Dan,
>
>Increasing gain can be had by resetting the bias if the transistor can stand
>the extra current through it. Also, you have to watch and not overload the
>stage ahead of it. However, you said it did better with about 4X extra drive.
>You would want to select a transistor that will withstand the amounts of
>current needed for the gain, and that it's frequency spec will match. Then
>re-do the bias so you acheive the gain with (or without) a new transistor. I'd
>check what the transistors specs are that's in there now. You may find it can
>handle it by doing the math. If it wont, look for one that will. Try looking
>through the Motorola books, etc. You might even be able to use a NTE, etc.,
>replacement by crossing the original, and finding one similar but a little
>stronger.
>
>Best,
>
>Will
>
>
>*********** REPLY SEPARATOR ***********
>
>On 3/15/06 at 6:59 PM Dan Sawyer wrote:
>
>
>
>>All,
>>
>>I have an older transistor based transceiver. I have separated the
>>circuit and substituted an external signal generator in place of the
>>internal circuit. The circuit drives a mixer, by varying the amplitude
>>the mixer performs better with about a 4x increase in drive.
>>
>>My question is: what is the best way to increase the output of an
>>amplifier stage?
>>
>>Is it as simple choosing a transistor with a higher beta?
>>
>>There are two nearly identical stages. Both are NPN, the collector bias
>>is a resistor - inductor in series and the emitter circuit is a
>>capacitor - resistor in parallel. Would reducing the resistor values
>>increase gain?
>>
>>If this question is too general - where is a good source for reading
>>about stage gain variables?
>>
>>Thanks - Dan
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>>
>>
>
>
>
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