Re: Variable gain preamp anyone?


Chris Moulding
 

I just want to raise a point about using the Loop Antenna Amplifier + with a variable supply.

It will be possible to reduce the gain by reducing the voltage applied to the amplifier.

The reduction in gain below 5 V is caused by the bias voltage dropping to a barely workable level.

The amplifier would be prone to generating cross-modulation and intermodulation at that point and I wouldn't recommend it.

For the best RFperformance run the amplifier with a bias-tee at 12 V and add an external attenuator between the amplifier and the receiver if you want to reduce the overall gain.

Regards,

Chris

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