Gates M-5136 Output XFMR

[CJ]

OPT is p/n AO-10864T



12AU7 directly coupled to the XFMR primary so this guy could be useful for other projects.

Threads out there on bypassing the mixer part to make a single tube preamp.

In the process of the tear down,

Here is the schematic>

 

[CJ]

This guy goes 4700 turns pri of wire that is 0.003, 24 layers, 195 t per layer I thought the coil would never end

Rotten wire probably from the heat, broke about 4 times per layer or about 100 times.

Points of interest are that the tertiary wind is broken into two sections around the primary, but has 198 turns on the inner section and 278 on the outer section.

100 ohm wind. Two secondary are 135 Ohms each if you go by the turns ratio but the voltage ratio will be different due to the DCR of the primary which s/b about 2000 ohms.


Core was steel, EI 625 ,
1 1/8 butt stack (natural air gap)

Another Gates product that uses the same transformer>

 

[CJ]

ok here we go with this guy,
can reminds me of Triad HS series,

 

[CJ]

new technique tried for removing the header
usually i use a big soldering iron which heats up the goop inside and makes a big mess and contaminates the solder joint etc,

this method leaves the goop intact for easier removal,

 

[CJ]

we got a sub lid down there that needs removal,
done outdoors

 

[CJ]

EI 625 29gaM6 1 1/8" stk

no that is not a nickel lam center section, just a tape mark,

shield lead attached to core bolt,

 

[CJ]

no paper in the gap,

 

[CJ]

lead breakouts,

 

[CJ]

outer 150 ohm sec, #33 wire, a gauge thicker than the inner secondary, maybe to keep DCR closer,

 

[CJ]

outer tertiary (feed back) wind, 0.003" wire, just two layers for 278 turns,

start is the splice at the bottom, finish is yel,

leads taped down so they don't flop around and break which would cause data loss,

 

[CJ]

last layer of pri wind, partial layer 183 turns, standard layer is 200 turns, 0.003" wire,

 

[CJ]

inner F/B wind, 1 layer of 0.003" wire, 198 Turns,

less turns than the outer F/B wind, so 198 + 278 = 476 total F/B turns,

unequal turns per section probably done to lessen oscillation due to phase shift,

getting the F/B wind to keep the amp stable is tricky work,

Look at the Manley vari-mu xfmr to see a similar structure,

 

[CJ]

and finally the last section, inner 150 ohm sec, 0.006" wire, 6 layers 545 turns,

great processing job on this coil, wax permeated all the sections,

failure was caused by over heating of the primary wire,

you can see the discoloration of the primary wire and feel the brittleness,

 

[CJ]

Print>

 

[rock soderstrom]

Good entertainment Thanks!!

 

[emrr]

I've always liked the sound of these output stages

 

[Cqwet Dbdfte]

Use class H insulated magnetic wire !