rafafredd
Well-known member
Note that Dynair used it as a pushpull transformer, thus canceling DC on the windings. I don´t think it´s simetrically geometrically wound, but then you won´t have much DC on the windings, just a little unbalance...
What should I do with my UTC A-22?
- Thread starter babyhead
- Start date
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NewYorkDave
Well-known member
Remember that most any audio transformer, even gapped, will give somewhat better performance (at least in terms of LF) with no DC through the windings. Just because a transformer is gapped, don't feel like you have to draw direct current through it :wink:
[quote author="NewYorkDave"]Remember that most any audio transformer, even gapped, will give somewhat better performance (at least in terms of LF) with no DC through the windings. Just because a transformer is gapped, don't feel like you have to draw direct current through it :wink:[/quote]
Yes but OTOH the low frequency could be much extended if the transformer were not designed to carry DC. I don't know of a no-dc counterpart for the A-22, but I've seen other UTC transformers that came with identical specs, except one of them capable of some DC, but less low range.
So I guess the A-22 was intended for an application that really required something like 20mA unbalanced DC.
JH.
Yes but OTOH the low frequency could be much extended if the transformer were not designed to carry DC. I don't know of a no-dc counterpart for the A-22, but I've seen other UTC transformers that came with identical specs, except one of them capable of some DC, but less low range.
So I guess the A-22 was intended for an application that really required something like 20mA unbalanced DC.
JH.
CJ
Well-known member
A-22, A-23, A-36, A37 are the same primaries stuffed on an M6 core. Secondaries have different turns for different output impedances.
Less turns than an A-20 primary to handle the current with bigger wire and not saturate the core with DC.
Equivalent of the A-22 in non dc might be the A-21, which has less pri turns to make room for some shielding.
I would imagine those 36 ohm primaries for the 22, 23, 36, 37 would give you about 1 henry pri inductance as opposed to 10 henries for your run of the mill A-10, which NYD correctly predicted as having a reduced low end response.
Any other questions?
Good. Then bow down to the iron king! :green:
Less turns than an A-20 primary to handle the current with bigger wire and not saturate the core with DC.
Equivalent of the A-22 in non dc might be the A-21, which has less pri turns to make room for some shielding.
I would imagine those 36 ohm primaries for the 22, 23, 36, 37 would give you about 1 henry pri inductance as opposed to 10 henries for your run of the mill A-10, which NYD correctly predicted as having a reduced low end response.
Any other questions?
Good. Then bow down to the iron king! :green:
SonsOfThunder
Well-known member
<bow>
You are da man, CJ! :green:
You are da man, CJ! :green:
[quote author="CJ"]A-22, A-23, A-36, A37 are the same primaries stuffed on an M6 core. Secondaries have different turns for different output impedances.
Less turns than an A-20 primary to handle the current with bigger wire and not saturate the core with DC.
Equivalent of the A-22 in non dc might be the A-21, which has less pri turns to make room for some shielding.
I would imagine those 36 ohm primaries for the 22, 23, 36, 37 would give you about 1 henry pri inductance as opposed to 10 henries for your run of the mill A-10, which NYD correctly predicted as having a reduced low end response. [/quote]
Thanks for the info. Is there anything about transformers you do _not_ know ??
So, does this mean the A-10 also uses the same core as the A-22 ?
And, does this mean that I can run 6mA of DC thru a A-10 ?
If the L is 10 times higher, I have SQRT(10) as much primary turns, so I could apply 20mA / SQRT(10) of DC. Does this make sense?
JH.
Less turns than an A-20 primary to handle the current with bigger wire and not saturate the core with DC.
Equivalent of the A-22 in non dc might be the A-21, which has less pri turns to make room for some shielding.
I would imagine those 36 ohm primaries for the 22, 23, 36, 37 would give you about 1 henry pri inductance as opposed to 10 henries for your run of the mill A-10, which NYD correctly predicted as having a reduced low end response. [/quote]
Thanks for the info. Is there anything about transformers you do _not_ know ??
So, does this mean the A-10 also uses the same core as the A-22 ?
And, does this mean that I can run 6mA of DC thru a A-10 ?
If the L is 10 times higher, I have SQRT(10) as much primary turns, so I could apply 20mA / SQRT(10) of DC. Does this make sense?
JH.
CJ
Well-known member
The A-10 and A-22 both use the 31UI 0.014 thick lam, but the material it is stamped out of is different.
The A-10 has a nickel core which means it can become magnetized by the dc 5 times easier than the M6 core use in the A-22, so you really do not want to run a lot of dc thru it, however, it is a two coil structure that is wound fairly accurately from what I have seen, so you might try experimenting with a few ma dc if connected in a balanced fashion..
I really don't know that much, I was just hamming it up as usual.
I don't think anybody knows that much about transformers, even the old timers say a prayer before they test a new design.
cj
The A-10 has a nickel core which means it can become magnetized by the dc 5 times easier than the M6 core use in the A-22, so you really do not want to run a lot of dc thru it, however, it is a two coil structure that is wound fairly accurately from what I have seen, so you might try experimenting with a few ma dc if connected in a balanced fashion..
I really don't know that much, I was just hamming it up as usual.
I don't think anybody knows that much about transformers, even the old timers say a prayer before they test a new design.
cj
[quote author="CJ"]The A-10 and A-22 both use the 31UI 0.014 thick lam, but the material it is stamped out of is different.
The A-10 has a nickel core which means it can become magnetized by the dc 5 times easier than the M6 core use in the A-22, so you really do not want to run a lot of dc thru it,
[/quote]
I see. Thanks for clarifying this, CJ.
JH.
The A-10 has a nickel core which means it can become magnetized by the dc 5 times easier than the M6 core use in the A-22, so you really do not want to run a lot of dc thru it,
[/quote]
I see. Thanks for clarifying this, CJ.
JH.
CJ
Well-known member
Sure. Let me know if you want me to open up a UTC A-23 right before your very eyes.
It's a 500 to 4/16 ohms at 30 dbm. What good is that? :?:
Only problem is that it's brand spankin new.
Hmm, might make a cool overdriven small git amp xfmr.
Like that darn car radio project that is still on the shelf.
Never mind, that's it! The car radio tube amp. Thanks guys! :razz:
It's a 500 to 4/16 ohms at 30 dbm. What good is that? :?:
Only problem is that it's brand spankin new.
Hmm, might make a cool overdriven small git amp xfmr.
Like that darn car radio project that is still on the shelf.
Never mind, that's it! The car radio tube amp. Thanks guys! :razz:
NewYorkDave
Well-known member
1H primary inductance? Nah, it's gotta be higher than that. Otherwise, it would be useless for full-range operation at its rated impedance of 500 ohms.
I'll measure the primary inductance of one of my A22s when I have some free time and will post the result here.
I'll measure the primary inductance of one of my A22s when I have some free time and will post the result here.
CJ
Well-known member
Depends on the bridge,
Gen Rad 1650-B 600 mH
Sencore 1.2 H
B-K 2.33 H
I want to open up this 23 but my foot is kiling me. Can hardly walk. They have this new treatment for ingrown warts where they inject chemothereapy into them. Stings like your walking on hot coals! Jeexz, feels like my whole foot is gonna fall off!
I guess I can saw while sitting down. :thumb:
Gen Rad 1650-B 600 mH
Sencore 1.2 H
B-K 2.33 H
I want to open up this 23 but my foot is kiling me. Can hardly walk. They have this new treatment for ingrown warts where they inject chemothereapy into them. Stings like your walking on hot coals! Jeexz, feels like my whole foot is gonna fall off!
I guess I can saw while sitting down. :thumb:
SonsOfThunder
Well-known member
[quote author="CJ"]UTC A-23...
Hmm, might make a cool overdriven small git amp xfmr.
Like that darn car radio project...The car radio tube amp.[/quote]
Ooo! CJ! You GO!
I like the idea very much. I have a very similar radio out of my 50 Buick project car (that one looks like the wonderbar version). I hope you are planning on a new PS? Unless you like the hummmmmmmmm.
I want to build a gtr amp out of an old Caddy radio. Solid state, single-ended, with treble boost like another person's "custom" recording amp... Someday!
Keep us updated!
Charlie
Hmm, might make a cool overdriven small git amp xfmr.
Like that darn car radio project...The car radio tube amp.[/quote]
Ooo! CJ! You GO!
I like the idea very much. I have a very similar radio out of my 50 Buick project car (that one looks like the wonderbar version). I hope you are planning on a new PS? Unless you like the hummmmmmmmm.
I want to build a gtr amp out of an old Caddy radio. Solid state, single-ended, with treble boost like another person's "custom" recording amp... Someday!
Keep us updated!
Charlie
