EMRFD Message Archive 11060

Message Date From Subject
11060 2015-05-02 10:42:35 jorschei Bi Directional amplifiers in the IF strip

Hi all,

I did some experiments in the past with Bi directional IF amplifiers. This circuit was used in a professional SSB transceiver. They are useful with SBL1 mixers fore and aft the amplifier strip and crystal filter in the middle. The BF981 type Fets on 10/12 volt can handle large signal amplitudes, an option after High level mixers. It is possible also to regulate the gain with the switch line on g2.  May be an good idée for experimenters. Gain of +30 dB is possible and have a good IF isolation.

73"Joris PE1KTH

11061 2015-05-02 11:26:18 farhanbox@gmail.c... Re: Bi Directional amplifiers in the IF strip

can uou upload clearer versions of the circuit?