Wessex F8401 amplifier #amplifier


G8FXB
 

Hi,

Unmodified they have a gain of about 20dB and NF around 4dB. I replaced all the FETs with MGF4919s on one and CE3512K2-C1 on another. I also converted the 1st stage to single ended. That reduced the NF to <1.4dB and increased the gain to 20-25dB. It also reduced the centre frequency. I didn't bother tweak it after that. 

The bias circuitry is quite fragile, physically and electrically. If you mod. one, be careful you don't damage it. It would be better to replace it with an alternative e.g. one of the Zetex bias controllers.

Regards,
Graham


am.andrej@...
 

Hi,

I'm looking for any information about Wessex F8401 amplifier. 7.85GHz-8.45GHz
Power supply range, NF and gain?
Maybe useful for DSN system as LNA ..need some info before buy it from allegro.

thanks info

73 de Andrej