Well, it was worth a shot. Since I don't have the circuit in front of me I can't make a more educated guess.
Since you caught the lead issue, I'll assume that you also did the diode test on the replacement parts. I have seen a few cases where the NTE doc's are wrong about the leads though. When the collector voltage goes to near zero, is it .2 V or .6 V? The first case is a saturated transistor; the second is a diode junction, which would suggest the pinout info is wrong. When I get back from some errands, I'll look in my NTE book to see if I can find any other clues. Happy hunting! Tom Holmes, N8ZM Tipp City, OH EM79 > -----Original Message----- > From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] > On Behalf Of Curt Nixon > Sent: Tuesday, February 26, 2013 11:43 AM > To: drakelist@zerobeat.net > Subject: Re: [Drakelist] R4A-B Detector Amp Q5 > > Hi Tom: > > Yes...there are the lead arrangement issues but I accounted for them. > The typical EBC Vs ECB issue. Easy in this case because they used the > triangular hole pattern instead of the inline pattern on both the R4A and B version > modules. > > Curt > > On 2/26/2013 10:49 AM, Tom Holmes wrote: > > HI Curt.. > > > > It almost sounds like there is a different lead arrangement on the > > 3393. Any well designed circuit of that era would have had to tolerate > > the typical high variability of Hfe to avoid tedious hand picking of > > parts, although that may have been done in this case. > > > > Tom Holmes, N8ZM > > Tipp City, OH > > EM79 > > > > > >> -----Original Message----- > >> From: drakelist-boun...@zerobeat.net > > [mailto:drakelist-boun...@zerobeat.net] > >> On Behalf Of Curt Nixon > >> Sent: Tuesday, February 26, 2013 10:40 AM > >> To: Drake Forum > >> Subject: [Drakelist] R4A-B Detector Amp Q5 > >> > >> GM All: > >> > >> Has anyone else had trouble getting a general purpose sub working in > >> the > > Q5 AM > >> detector amp position? > >> > >> I tried several close NTE GP subs and also a 3393 which is same > >> parameters > > ex > >> Hfe which is slightly different. > >> > >> The transistor comes on but with the grounded emitter, pulls the > >> collector > > voltage > >> to near zero. As soon as I put in a "real" orignal > >> 3394 from a R4A, it works as it should--good fidelity and collector > > voltage at about > >> 5V from the supply rail of 10V. > >> > >> Is this design so sensitive to Hfe as to be marginal or need to be > >> hand > > selected? > >> Certainly the 3393 is well within the spec range of the 3394. > >> > >> Thanks > >> > >> Curt > >> KU8L > >> > >> _______________________________________________ > >> Drakelist mailing list > >> Drakelist@zerobeat.net > >> http://mailman.zerobeat.net/mailman/listinfo/drakelist > > > > > > _______________________________________________ > > Drakelist mailing list > > Drakelist@zerobeat.net > > http://mailman.zerobeat.net/mailman/listinfo/drakelist > > > > _______________________________________________ > Drakelist mailing list > Drakelist@zerobeat.net > http://mailman.zerobeat.net/mailman/listinfo/drakelist _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
