• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Modifying a PT?

Recently received a 350W custom PT. I spec'ed it out for 115V primary, but it came with 220/230V primary instead. Cannot use this unless I run extension cord from laundry room- lol. I see from research here that primary is most likely first winding, so is there easy (or relatively easy) way to modify it- ie separate into 2 equal windings to operate in parallel for 115V operation? Or should I sell it and take the loss?
Thanks,
Jim
 
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I would too, unless it was my mistake and not the winder’s. If I were spec-ing a custom trafo, I’d probably spec dual 115/120 primaries so that mistake couldn’t ever happen. It would be useable regardless. Winding my own I’d just start over if I did it wrong. Put in a little less than the full core, check ratios before buttoning everything up.
 
I spec'ed it out for 115V primary, but it came with 220/230V primary instead.
That´s a GROSS error.
I do NOT trust such a transformer, at all,what else can be wrong?
Selling it would be same as passing a fake bill to an unsuspecting person, just to recover your loss.

Where did you order it from?
Who made the mistake, you or the winder?
How do you know primary is 230/240V?
Please post a label picture.
What are the needed specs?
 
Diagram below was submitted at time of order. Ad said 220/230V 'default' primary, also said can be customized, so I messaged the vendor and asked at time of order- he said 'yes, can be customize'. Trafo came like pic shown- Label shows 220/230V. Ohm'ed out windings and located primary, then measured voltage @ all secondaries. They weren't right either...👎Opened dispute to no avail (so far)👎 Moderator said I need to follow the wiring instructions... of which there were none. It's an ongoing case- promised the vendor I won't flame them if we can come to some type of settlement.
I'm not holding my breath-
Jim
 

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Essentially that's a Europe only tfmr, it'd be no good running on the mains here in the UK as it's often up to 250v, unless that is it's a good quality tfmr, which it doesn't look like it is. I see there's no mention of the frequency either, so it's probably wound for 50hz less than optimal. It looks very small too, IE not many turns per volt & not enough laminations meaning it'll have poor regulation. They probably just told you a load of old bollocks to get the sale that or as you and the vendor speak different languages there's a SNAFU of understanding.

If you want cheap good quality mains tfmr's find an old toroid, strip it of it's secondary and wind the heater and HV secondary yourself, it'll take time to do the latter but less so if you use a big core.

Andy.
 
Diagram below was submitted at time of order. Ad said 220/230V 'default' primary, also said can be customized, so I messaged the vendor and asked at time of order- he said 'yes, can be customize'. Trafo came like pic shown- Label shows 220/230V. Ohm'ed out windings and located primary, then measured voltage @ all secondaries. They weren't right either...👎Opened dispute to no avail (so far)👎 Moderator said I need to follow the wiring instructions... of which there were none. It's an ongoing case- promised the vendor I won't flame them if we can come to some type of settlement.
I'm not holding my breath-
Jim
Ok, now I am certain it is not your fault.

That transformer in NO WAY meets your specs.

  • WHERE is the 10V center tapped winding?
  • WHERE are the 2 x 110V primaries?
  • WHERE is the 6.3V 8A center tapped winding? Label mentions 1.6A
  • WHY are all labels in Chinese with NO English ones nor an accompanying sheet?
  • WHO asked for a 5V winding?
  • WHERE is the centertapped 25.2V winding?
  • WHO asked for TWO 6.3 windings? (by the way,of insufficient current).

You have been conned, pure and simple.

To begin with, start a dispute through your credit card bank and STOP that payment.

There is NO "wiring instruction" in the World which allows that ... thing .... to be wired per your drawing design.

I mean, I hope you submitted it, and it was not just a verbal description on the phone.

Do not send the transformer back, freight will cost 10X of what you have already paid.

Get your money back and RUN!!! from that manufacturer and that "moderator".

And who is that "moderator" anyway?

What thread/page is related to this?

Only settlement possible is getting your money back, plus Customs expenses, if any.

Please post a link to Ad, or at least a screen capture, to avoid Forum Members falling in that same trap.
 
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Ok,I had my Polyglot Son translate the Traditional Chinese symbols.
Which does not fully clear the mess, at all, that transformer in no way matches what was ordered:

trafochino label.gif

1 -5 : BLACK
2 : RED
3: VIOLET (PURPLE)
4 - 6 : BROWN
7 - 8 : GREEN
10 - 11 : BLUE
12 - 13 : YELLOW
9 "is not a colour" , it means something like "group/arrangement/set" so it might mean "2 sets of 4A" (each)

I guess it helps know better what they sent, which in my view is NOT what you asked for.

Even worse, Language problems aside, it does NOT match your SCHEMATIC, which is "universal" 🙄
 
Even WORSE: some colours are repeated in different windings,even opening the path for DEADLY mistakes, such as:

* BLACK is used both in Mains Primary and Secondary, it is both Mains start end and HV center tap.

* Apparently there are two sets of 6V 4A windings, all 4 wires are GREEN, no indication of phase whatsoever, or even belonging to the same winding.
"Wiring diagram" my 4ss.

* The 5V winding for your Tube Rectifier has the proper colours ... pity you din´t order it 🙄

* The 6.3V 1.6A is reasonably well identified, pity you didn´t order it either.

* NO centertap for the 6.3V winding and of course fully missing center tapped 25.2V winding.

Really, you must show us WHO they are, as a matter of public service, flaming aside.
These guys are deadly.

Bonus points for the flimsy cardboard box it was sent in.
 
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To begin with, start a dispute through your credit card bank and STOP that payment.
Considered that...
But I order many parts from AliExpress for my 26yr electronic repair biz. Probly just take the "L" on this...shouldn't have mixed business & pleasure🙄
Please post a link to Ad, or at least a screen capture, to avoid Forum Members falling in that same trap.
I'll start new thread for that warning... Don't want members here to meet same situation.
 
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Ok,I had my Polyglot Son translate the Traditional Chinese symbols.
Which does not fully clear the mess, at all, that transformer in no way matches what was ordered:

View attachment 1109893
1 -5 : BLACK
2 : RED
3: VIOLET (PURPLE)
4 - 6 : BROWN
7 - 8 : GREEN
10 - 11 : BLUE
12 - 13 : YELLOW
9 "is not a colour" , it means something like "group/arrangement/set" so it might mean "2 sets of 4A" (each)

I guess it helps know better what they sent, which in my view is NOT what you asked for.

Even worse, Language problems aside, it does NOT match your SCHEMATIC, which is "universal" 🙄
Ohm'ed out the windings and figured out what was what. Tell you son thx for translating-
Looks like trafo was not customized in any way- Basically off the shelf chunk- see below screen shot of sales rep's response to my primary winding Q-
 
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To begin with, start a dispute through your credit card bank and STOP that payment.
Considered that...
But I order many parts from AliExpress for my 26yr electronic repair biz. Probly just take the "L" on this...shouldn't have mixed business & pleasure🙄
So what?
If they made a mistake, they MUST solve it, one way or the other.
Or it will be repeated in the future.

To boot, you do not have a problem with Aliexpress, you have a very real problem with a specific seller.
Do you fear they will put you in some kind of blacklist and not sell you any more? 🙂

By the way, I bet Aliexpress is swamped with complaints every day (I wonder why 😉 ) , yours is just "one more".

I suggest you follow through with the complaint; if anything, to know what happens.
Better learn with this one and not in a future expensive one.

Your choice, of course.

EDIT:
on the other side, you ordered and paid for an off the shelf standard pre-made item,

EL34 KT88 6L6 electronic tube push-pull circuit universal EI power transformer, 350W 360V-0-360V 0.4A; 6.3V 4A; 6.3V 4A; 5V 4A​

1 order

US $61.66 - 64.66
of which there are still
391 Pieces available
and they sent exactly that, the label matches above description to a T.

So the problem boils down to: did they clearly acknowledge your custom design drawing or you just assumed they did?
 
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So what?
If they made a mistake, they MUST solve it, one way or the other.
Or it will be repeated in the future.

To boot, you do not have a problem with Aliexpress, you have a very real problem with a specific seller.
Do you fear they will put you in some kind of blacklist and not sell you any more? 🙂

By the way, I bet Aliexpress is swamped with complaints every day (I wonder why 😉 ) , yours is just "one more".

I suggest you follow through with the complaint; if anything, to know what happens.
Better learn with this one and not in a future expensive one.

Your choice, of course.

EDIT:
on the other side, you ordered and paid for an off the shelf standard pre-made item,
of which there are still
and they sent exactly that, the label matches above description to a T.

So the problem boils down to: did they clearly acknowledge your custom design drawing or you just assumed they did?
There is a couple of other Aliexpress vendors that have a specific "DIY" colour option when you select the type of transformer. If you select a different type, you get a pre-defined one.
One thing to take into account with Aliexpress is that they rely on automatic translation, you can see "cattle", "cows" etc when reading descriptions about transformers.
None of that justifies sending the wrong transformer. The OP clearly sent the transformer description in a picture. No language issues.
 
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