Transformer notation question and mc77/1176???

[ihscoutlvr74]

Gents,

I haven't seen a transformer construction notated like this before:

Would this just be a basic split primary trafo?  Haven't seen the primaries next to each other like this compared to stacked vertically in an image.  Could this possibly be used for a class A output with feedback like on an MC77?  If not, can it be used in a push-pull style output for a g1176 or other derivative?  The dotted lines go to a common ground pin.

Thanks, Nathan

 

[CJ]

that is just a 1:1, probably a "bridging" transformer like i am hacking next door, .

the primary is wound different, they use a red and a green wire side by side, then combine start to finish,

this is called bi-filar winding, or "hold two" as one gentleman here likes to call it,

standard notation for "bi-fi" is probably what you see on your diagram,

you get nice, even matched, same dcr, same inductance coils when you wind this way,

this means really good noise rejection coming from a long line out cable, etc.

but you can not use this method everywhere, as the leakage C is horrific, as you are winding a capacitor,

so look for bi-fi on a primary, or low ratio xfmr, maybe an inerstage, but rare on a step up secondary,

lots of bi-fi iron in the Langevin A-16, and also on the  Peerless K-241-D primary, and a few others,

Du Kane mic input pri .is anotherocation,

i think i have some bi-fi coming up tonight in this LS 140 hybrid, so check the Lab in a while, 

 

[abbey road d enfer]

this is called bi-filar winding, or "hold two" as one gentleman here likes to call it,

I use the french locution "deux fils en main" (two wires in hand), although I'm not a gentleman