Sir Lou . . . . .

The unit now works, however I did notice that the base and emitter leads on the replacement transistor exit the case at different locations that the original unit
(base and emitter leads are interchanged mechanically).

AHHH Yes . . . the old:

CEB versus CBE Syndrome . . . that any one dealing with the onset of plastic transistors will be experiencing . . . . . certainly hoping that you have a full lead length on units so that you can transverse those B and E leads around each other to mate properly to the PCB holes or socket.

Back in the earlier cased TO-5 and TO-18 configurations there was no worry . . . . with their fixed triangular lead placements.

BUTTTTT . . . should you get the "P" versions of those units you had to check to see the basing assignments on those side by side tri lead reconfigurations.

I ASSUME that if I had not interchanged the base and emitter that the transistor would not work or even may be damaged, correct?

Assuredly it would not work, but no problem on damages on that particular circuit position, the problem would be if the COLLECTOR connection was involved, as that is the element involved with the the power input aspect of an NPN transistor.

I see that this set used so MANY of those 121-697 transistors that you should have had no problem in swapping around two of them in analysis procedures.

I do remember getting one of those '7000 SS Trans units working again back in the early '90's for an associate.

That particular repair involved that sets FM aspect . . . . .and you were questioning the use of a 2N2222 or 2N2218 . . . . . well . . . in my case, I ended up using a 2N2222 in the FM RF slot.

The '2222 is a well and time qualified line item used prolifically in Military-NASA-Industrial design . . . . and I typically just call them "quad twos".

Now the 2218 is the big power brother of the 2222, and these circuit utilizations are not requiring that increased power necessity.

Good design procedure would like to see a transistors Alpha characteristics being up to 10x of your operational frequency, in the case of this sets FM section that would be the use of 1 gig transistor in those RF amp and mixer -osc positions. (Which your ECG part meets).

Just in my consideration of using a 2222 with its Alpha, being but just a 1/4 of that range limit, I tried out the set at reduced supply voltage, with it still operating flawlessly at 1/4 reduced voltage.

No faults found . . . . plus no following complaints from him in ~ 19 years now in his pulling in a 40 mile distant station . . . probably daily . . .in his listening to Rushty Limburgers Sagas.

Your current 121-697 in the AM mixer stage utilization should merely be idling on one cylinder for that lower frequency use.

Nowwwww . . . on the PSB section I DO see that they stepped on up to a different numbered . . . higher frequency rated transistor . . . in its two slots.

Thassit . . .

73's de Edd