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TIA amplifiers

George
 

Ok thanks, if I get I'll try to use. Allso good BFS17.
George UR4CRG/RX3ARG

ajparent1/KB1GMX
 

An alternate improvement is replace Q10/11/12 with mmbt2369 or BFr106
as the 3904 is not impressive at 45mhz.

Allison

George
 

Dear members you can check:
1. Add parallel to R12 C=470 pF: in my analiser I could see 3 dB gain rising on 30 MHz, 0805 smd resistor over R12;
2. Added two 100 Ohm  to collectotrs Q11 and Q12 (had to cut PCB roads to them). Emitter-follower do not like HF signals and small collector resistor gives light feed back.
3. After this reception has become more sensitive - I had to change my switching Power Supply to transformer analog one.
Best 73s to all George