United Transformer HA-100

[EricM]

Does anyone happen to have a data sheet or know the pinout of a UTC
HA-100 input transformer? It has 11 pins; 1 through 10 and a
ground. The particular unit I have was removed from something prior
to my owning it and has pins 8 & 9 shorted, 10 and ground shorted, and
3 & 4 shorted. No wire fragments or anything to go by. Wanting to
use is as an input transformer in a solid state NE5534 opamp circuit -
maybe barking up the wrong tree? Need something to take a line level
signal and match to the input of the 5534. Others have suggested
using an older transformer like this one for improved sound quality
but might not be right for the application. Could tell if I just had
info on the pinout. Anyone have access to this information? Thanks!

 

[kilowatt]

Does anyone happen to have a data sheet or know the pinout of a UTC
HA-100 input transformer?  It has 11 pins;  1 through 10 and a
ground.  The particular unit I have was removed from something prior
to my owning it and has pins 8 & 9 shorted, 10 and ground shorted, and
3 & 4 shorted.  No wire fragments or anything to go by.  Wanting to
use is as an input transformer in a solid state NE5534 opamp circuit -
maybe barking up the wrong tree?  Need something to take a line level
signal and match to the input of the 5534.  Others have suggested
using an older transformer like this one for improved sound quality
but might not be right for the application.  Could tell if I just had
info on the pinout.  Anyone have access to this information?  Thanks!

Hi
This may help somewhat, UTC catalog does not show pinouts..I gleaned
this
from image that was in picture in catalog.

HA-100 is a Microphone transformer 30 -20,000Hz +- 1dB You may want to
use a
600 ohm to 600 ohm transformer like an A-20.
'Line level', may be 47K in some apps.

There is some symmetry to the terminals. 2,3 means connected together
as is 4,6.
Then 50ohms is from the two sets, wire one to 2,3 and wire two to 4,6

INPUT
50Ohms 2,3 and 4,6
125/150 ohms 1,3 and 4,5
200/250 ohms 2 (join 3,4) 6
333ohms 1 (join 3,3) 5
500/600 ohms 1( join 3,4) 6

Output is 60,000 ohms overall split winding

kw

 

[[email protected]]

bg is correct in that this transformer is a low impedance microphone-to-grid
matching unit. Its turns ratio is about 1:10, meaning that if your primary line
level voltage is 1VAC, then the transformer's secondary level is going tobe
around 10VAC (assuming the impedances allow it). I don't think that's what
you're after.

Of course, you could always send the secondary into a resistive voltage divider
to get the level back down so the NE5534 input isn't overdriven. Better still,
connect the transformer in reverse; using the secondary as the input and the
primary as the output. That would reverse the turns ratio to 10:1, so the
output level would be 1/10 the input level. If you need to maintain the
frequency response characteristics of the transformer, then you need to
experiment with source and load impedances that the transformer sees.

A better choice would be a 1:1 ratio transformer; something like a 600:600 ohm
matching transformer.

What microphone puts out 1 volt? Millivolts is more like it.

G²

 

[EricM]

TheOPsaid he had line-level audio... not a mike.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate charactersin the
address)

Life is like a roll of toilet paper; the closer it gets to the end, the faster
it goes.






What microphone puts out 1 volt? Millivolts is more like it.

G²

I was intending to use it as a line level input, however I tried it
and got nothing. Removed it and patched the line level input directly
to the R/C network at the input of the first opamp and I get a very
low level signal but adjusting the level pot doesn't seem to do
anything. Will try the 600:600.

 

[EricM]

I was intending to use it as a line level input, however I tried it
and got nothing. Removed it and patched the line level input directly
to the R/C network at the input of the first opamp and I get a very
low level signal but adjusting the level pot doesn't seem to do
anything. Will try the 600:600.

Sounds like your opamp circuit isn't working... or not wired correctly. Is it
possible for you to post a schematic of your circuit?
alt.binaries.schematics.electronic is a good place to post it. If you can do
ASCII art, just post it here.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate charactersin the
address)

Life is like a roll of toilet paper; the closer it gets to the end, the faster
it goes.

Actually I found part of the problem; was using a cutoff switch from
an old parts bin and it was bad. The circuit works fine. Don't
really need an input transformer at all, except the bass seems kind of
thin maybe the 600:600 would correct that. I'm going to be driving an
old tube amp with adjustable inputs at 50, 200 or 500 ohm - would it
be advisable to use a 600:600 on the output and go into the 500 ohm
tap of the tube amp's input? If I understand correctly op amps are
very high impedance on the input and output.