[amsat-bb] Help for Landwehr El. 70 cm preamp GaAsfet

Hi all, in 1989/90 I bought a Landwehr Electronics preamp for 70 cm band and all was OK till now.A few weeks ago,for some reason,( may be an electrical shock during a storm ) the GaAsfet decided to die. Unfortunately it is impossible to read the name of the GaAsfet to be replaced and on Landwehr technical sheet for 70 cm preamp,the GaAsfet is listed as IC with no particular specification. No useful answer to my e-mails about the type of GaAsfet used from Landwehr El. in Germany. So,I hope someone can help me to find the name of that GaAsfet, I would appreciate. Thanks. Gianfranco Ronconi IK4GMI