UTC Y-6431 Blueprint Fairchild 670

did the dissection but never wrote it up,   

Dissection Thread>

http://groupdiy.com/index.php?topic=35548.msg436342#msg436342

Y-6431 = Fairchild 670 Control Amp Input,

this is the one in the big square can,

it is just like the UTC A-10 and HA 100-X except:

the lams are of a lower perm alloy (50/50 Ni)

there are cu foil screens between the pri and sec winds,

turns ratio is 1:9.6 instead of 1:10,

and the hookup schematic has a cross coil configuration,

this means that the the top lead of the pri is connected to the A coil, and the top lead of the sec is connected to the B coil,

so the Pri consists of S-F-F-S  and the sec F-S-S-F,

a few other UTC's do it like this like the LS-68,

i do not know what this does to the response or leakage, fun to do an experiment and find out some day,

let me know if you see any errors,

fixed problem with led numbering on wind diagram, 

please reload and it will never happen again,

got a UTC LS-68 going up next which is a really nice splitter,

cj

CJ said:

............the lams are of a lower perm alloy (50/50 Ni).............

Click to expand...

CJ,
Impressive work!

What do you believe this do in the response frequency and sound??

Thanks
Opacheco

this transformer feeds the control amp, and the control amp output gets rectified and filtered, so the only thing that might be affected by the steep 1:9.6 turns ratio would be a slight drop in HF frequencies reaching the control amp,

and that Chi Town PSO-150 OPT will probably roll off some HF as well, which will mean just a tad bit less HF getting rectified, but usually the HF is of a low voltage value compared to bass, so that Y-6431 will probably not have much to do with the sound,