40 V AC in the green terminals of 6,3V

[rafaelctt]

Hello, is it normal that in vacuum(unloaded), there is 40 V AC in the green terminals?
Thank you

[pdf64]

Please explain exactly how you measure 40VAC; ie where are you putting the meter probes?

[Latole]

OP make some mistake for sure.

[sluckey]

I've never measured voltage in a vacuum before. I suspect you do not have one meter probe connected to a green wire and the other meter probe connected to the other green wire. If you do have the meter connected properly, then the meter is not set correctly, or the meter is lying to you, or maybe just needs a new battery.

[JPK]

On the Apollo 13 mission, as a test, I measured voltage in a vacuum and it was the same. 


All joking aside this is not normal. Possible causes were already mentioned above. It might measure close to 7 VAC unloaded but not 40 VAC.

[acheld]

Could the primaries be hooked up incorrectly?   Mains voltage?

Hi-rez photos might help us understand the situation.

[kagliostro]

Instrument set for DC instead of AC ?

Franco

[kagliostro]

No, STOP ALL, which are the voltages you measure on the other windings ???

Franco

[rafaelctt]

[rafaelctt]

Instrument set for DC instead of AC ?

Franco

voltmeter at 600 V AC

[pdf64]

Ok, that seems weird, it’s worth trying a new battery in the meter, and measuring the 6.3V AC on another amp.

[kagliostro]

+ 1 for pdf64

Franco

[rafaelctt]

To make this measurement, is it essential to have the green-yellow wire connected to ground?

[Latole]

Ok, that seems weird, it’s worth trying a new battery in the meter, and measuring the 6.3V AC on another amp.

IMO a defective battery will show dimm digits

[sluckey]

To make this measurement, is it essential to have the green-yellow wire connected to ground?

No. Try the 200V range. What does the meter read when you are connected to the yellow wires?

New battery in meter?

[Latole]

Where are the probe connected to the meter ? ; picture is cut
Meter look defective.

[rafaelctt]

To make this measurement, is it essential to have the green-yellow wire connected to ground?

No. Try the 200V range. What does the meter read when you are connected to the yellow wires?

New battery in meter?

ok i will measure it and tell you

[rafaelctt]

Where are the probe connected to the meter ? ; picture is cut
Meter look defective.

That's not the meter. It's a simulation.

[Latole]

ok i will measure it and tell you

I am not reassured if it is like the transformer measurement......

Put new good one. !

[PRR]

> IMO a defective battery will show dimm digits

Depending on design, sometimes a low battery reduces the internal reference and the external voltages will read high. However the cases I have seen, 5%-10% high, not 600% high.

Put a 1k (or 1.5k) resistor load on the winding and try again. Electronic meters are so very sensitive that they will pick up capacitive leakage from a broken winding to other windings like the 230V and 600V. House electricians who run long cable with 0V and 120V and a third UN-connected wire for later wiring may see 59V on the "vacuum" (unconnected) wire. Some electrician-market meters add loading to reduce "phantom" voltages.

[kagliostro]

... "phantom" voltages.

When I rebuilded my house wiring my phase finder captured lot of thoise phantoms

Franco

[DummyLoad]

To make this measurement, is it essential to have the green-yellow wire connected to ground?

No.


--Pete

[rafaelctt]

Fixed!
Thank you all. It was indeed a problem with the voltmeter. I have changed to another and solved.

[Latole]

Fixed!
Thank you all. It was indeed a problem with the voltmeter.  and solved. 

That is what I wrote.
I hope you bought a good one.

[kagliostro]

Any $ spent to keep a good equipment is a gained $

Franco

[Latole]

Any $ spent to keep a good equipment is a gained $

Franco

100 %right.

A pro may use cheap stuff because he will know if tools are working or not. And know their limits.
Newbie, no. He must use quality and fool proof tools.
Buying cheap is most of the time, throw out the money

[rafaelctt]

I don't usually work with very bad equipment. I think it was a probe problem.

Thanks!!

[rafaelctt]

Fixed!
Thank you all. It was indeed a problem with the voltmeter.  and solved. 

That is what I wrote.
I hope you bought a good one.

I did the measurement with an oscilloscope to check if there was any induction

[Latole]

You think ?

Probe are easy to check if the are good or not.

Buying good equipment is the easy part. Knowing how to use them it is another story. Too many people want to work in the amp now, not take few hours to study before.

I don't say it is you

[rafaelctt]

You think ?

Probe are easy to check if the are good or not.

Sorry for the inconvenience. This is what happens when you don't review measurements. I asked you if it could be logical because it's the second tube amp I've made. (I've made dozens of solid state.) And yes, a probe will be checked, of course. Thank you anyway. I'll try to bother as little as possible.

[rafaelctt]

You think ?

Probe are easy to check if the are good or not.

Buying good equipment is the easy part. Knowing how to use them it is another story. Too many people want to work in the amp now, not take few hours to study before.

I don't say it is you

Totally agree with you friend. I assure you that is not the case. I have been in electronics for many years but I think that anyone can make a mistake. I apologize

[bmccowan]

In my opinion, no apology is necessary. That's what the Forum is for, finding mistakes and fixing them. Or avoiding them in the first place. You were trying - that's what counts.

[sluckey]

Why would you use that cheap $10 XL830L when you have much better equipment available?