Twist Turner

UTC LS-140 I'm stumped!
« on: May 21, 2020, 10:55:07 AM »
I'm building a transformer filled "color box" I've got 10 in there right now 600:600.........here's one that is just totally stumping me. I picked up a UTC LS140, checked it for continuity and it's good, wired it up according to the info on the UTC terminals chart and i'm getting nothing. So i checked wires to make sure there wasn't a broken wire, wires all good, measuring continuity at the xlr's same as the transformer......but no sound. I thought maybe there was the possibility it was out of phase and cancelling so i swapped leads on one end.........no sound.

Any ideas the transformer at least by continuity appears to be good yet i'm getting no sound......the other 9 in the box all work perfectly.


UTC LS-140
« Reply #1 on: May 21, 2020, 12:13:41 PM »
piqued my interest,
LS-140 labeled as a hybrid repeat coil.
tested a new old stock 140;
strapped terminals 2 to 3,   terminals 6 to 7.
no issues,  flat (-0.3 dB) from 20 Hz to 20 kHz, to and from 600 ohms.

EmRR

Re: UTC LS-140 I'm stumped!
« Reply #2 on: May 21, 2020, 01:02:40 PM »
Does it look at all like it's been opened?   
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

mjrippe

Re: UTC LS-140
« Reply #3 on: May 21, 2020, 01:31:49 PM »
piqued my interest,
LS-140 labeled as a hybrid repeat coil.
tested a new old stock 140;
strapped terminals 2 to 3,   terminals 6 to 7.
no issues,  flat (-0.3 dB) from 20 Hz to 20 kHz, to and from 600 ohms.

Any chance for DCR or inductance readings?

Twist Turner

Re: UTC LS-140 I'm stumped!
« Reply #4 on: May 21, 2020, 01:38:05 PM »
reading with the ohm meter was around 50.5- 51 if i remember correctly that is with 2/3 and and 6/7 jumpered.

Not only didn't it look opened, there it didn't appear to have ever been soldered  before either

moamps

Re: UTC LS-140 I'm stumped!
« Reply #5 on: May 21, 2020, 07:30:06 PM »
Maybe one coil is unintentionally internally swapped/out of phase. Apply signal to 1 and 3 and measure signals at all remaining three coils.

rackmonkey

Re: UTC LS-140 I'm stumped!
« Reply #6 on: May 24, 2020, 01:53:57 AM »
What ever happened with this? Did you get it figured out?
Whether you think you can or you think you can't, you're probably right.

Twist Turner

Re: UTC LS-140 I'm stumped!
« Reply #7 on: May 24, 2020, 12:40:00 PM »
What ever happened with this? Did you get it figured out?

No not working.  What is strange is both 1/2's of the input windings work but when jumpered at pins 2/3 and connecting 1 and 5(there is no 4) when measuring continuity it shows i am getting continuity between the 2 combined but i get no output.......

Re: UTC LS-140 I'm stumped!
« Reply #8 on: May 24, 2020, 01:17:59 PM »
the ladies that wound UTC coils sometimes made mistakes.  maybe the polarities are reversed.

Twist Turner

Re: UTC LS-140 I'm stumped!
« Reply #9 on: May 24, 2020, 02:27:17 PM »
the ladies that wound UTC coils sometimes made mistakes.  maybe the polarities are reversed.

I tried reversing polarity on the output and got nothing, maybe i should try the input


EmRR

Re: UTC LS-140 I'm stumped!
« Reply #10 on: May 24, 2020, 02:30:31 PM »
It'll be interesting if a coil has flipped polarity.  I've yet to see one that canceled well enough to be effectively silent, there's usually enough of something to sound like a failure. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

rackmonkey

Re: UTC LS-140 I'm stumped!
« Reply #11 on: May 24, 2020, 05:40:55 PM »
It’s a weird one.  I’m pulling a couple out to fiddle with tonight to see if I can come up with any ideas for comparisons, other than the obvious.

I do recall that the 140 is a weird beast. Very sensitive to source and especially load Z for a 1+1:1+1 transformer. Really big response variations IIRC. But it’s been a while since I messed with one.

I think I remember CJ tearing one down and commenting on how unusual the winding structure was, but I can’t find any pictures or posts on a quick search.
Whether you think you can or you think you can't, you're probably right.

EmRR

Re: UTC LS-140 I'm stumped!
« Reply #12 on: May 24, 2020, 06:06:29 PM »
I think I remember CJ tearing one down and commenting on how unusual the winding structure was, but I can’t find any pictures or posts on a quick search.

I saved this in Dec 2009, don't know where the thread is:

Quote
this thing turned out to be pretty weird,


ok, so it Is another 31UI, wtf, over? plus, they forgot one of the coils, i am going to call UTC,  

this is a Hybrid transformer,


this is something i have not seen since i worked at Aydin Energy building transformers,  folded shields:


so that center winding in this pri-sec-pri rig is buried under two copper shields whose ends are tucked,

this keeps cross talk down to about -92 db , catalog spec,


more weirdness, bi fi windings, this is the splice from the outer pri to the inner pri,>

heavy cardboard in between pri-sec, another weird tweak. usually you want  copper in the window,


how do they wind these things? slowly.. we use to put a piece of mono fish line in between, better C,


 there is a piece of copper in there, inside the yellow mylar, it gets wrapped around the leads,





first layer.  all thw windings are bi-fi,  200t - 400f- 200t, so twice that = 800 turns , pri, 800 sec.

Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

moamps

Re: UTC LS-140 I'm stumped!
« Reply #13 on: May 24, 2020, 06:59:01 PM »
....(there is no 4) ....
Is it LS-140 at all if there is no pin 4? On Pin 5 should be wired one secondary coil. Could you post a picture of it?



EmRR

Re: UTC LS-140 I'm stumped!
« Reply #14 on: May 24, 2020, 07:23:52 PM »
Is it LS-140 at all if there is no pin 4? On Pin 5 should be wired one secondary coil. Could you post a picture of it?


Mmmm.   True. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

PRR

Re: UTC LS-140 I'm stumped!
« Reply #15 on: May 24, 2020, 09:33:51 PM »
I saved this in Dec 2009, don't know where the thread is:

https://groupdiy.com/index.php?topic=35773.msg439639#msg439639

All images rotted away.

CJ

Re: UTC LS-140 I'm stumped!
« Reply #16 on: May 25, 2020, 03:52:10 AM »
it is supposed to kill all the sound, that is what hybrids do.

only the operator is  allowed to be heard.

"i'd like to make a collect call to US Bail Bonds in Tijuana"

'one moment please..."
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

CJ

Re: UTC LS-140 I'm stumped!
« Reply #17 on: May 25, 2020, 04:03:38 AM »
maybe this is not a hybrid, we did hack a hybrid, was that the LS-68?

this one looks normal, i have to clean up the print,

all my transformer prints are in the Magnetics  forum under their brand name.

here is the UTC section.

https://groupdiy.com/index.php?topic=74166.0

« Last Edit: May 28, 2020, 02:25:32 AM by CJ »
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

CJ

Re: UTC LS-140 I'm stumped!
« Reply #18 on: May 25, 2020, 04:17:26 AM »
me wrong. again.  it is the 141 that is the hybrid>
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

Twist Turner

Re: UTC LS-140 I'm stumped!
« Reply #19 on: May 27, 2020, 08:20:12 AM »
I've been busy with some other projects the last week. i'll dig into this transformer later further later in the week.


 

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