I would simply slap a 741 into position to see how it behaves. Also check those zeners for +/- 14.7V. They go bad. Regards Paul WB8TSL
On Mon, Sep 11, 2017 at 5:56 AM, Ulf Kylenfall via time-nuts < [email protected]> wrote: > > Continuing my efforts to fix the 5065A... > > There was something wrong in the A7 (AC Amplifier assembly). > > DC balance of the input stage was completely off-scale > and one of the 1854-0023 transistors had an open junction.Luckily I had a > small supply of them but I also discovered that > the OP-Amps were old "seven of nines" (709). > > There are several different manuals floating around on the internet, > and the hard copy that I have shows two different versions > of A7. One with 709 and one using 741 that is also different > in terms of circuit design and layout. > > I am considering redesigning A7 using modern CAD and also > purchasing boards from a professional vendor, but first I would like > to know if anyone has tried both versions and if there are any > improvements. The modern 741-version uses DIP-socketed > OP-Amps so that version could be tried with even better > types. > BR > Ulf Kylenfall SM6GXV > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
