Resistance/Voltage checks

[troplin]

I've just finished the assembly of my S.E.X. 3.0

There are some measurements that seem just a little bit off, namely H2, H5, H4 and H7.
The expected resistance is * (wandering in the 10Ks-100Ks), where mine are wandering around 200 Ohm. Is this ok?
Also the voltages for those are a bit high:
H2, H5: both 3.45V (should be +/- 2.8-3.2)
H4, H7: both -3.23V (should be +/- 2.8-3.2)
What does the +/- mean in the manual? My measurements are both + for H2 and H4 and both - for H4 and H6.

Additionally, I've got the problem that my multimeter only measures up to 250V. Is there something that I can do to measure the remaining terminals anyway or do I really have to buy a new meter?
The one I have is quite new too, but unfortunately I wasn't too careful when selecting a model.

[fullheadofnothing]

the values signified with a * are going to vary from ohmmeter to ohmmeter because these terminals are connected to the filter capacitors, which try to charge themselves off the battery in the meter, causing a fluctuating reading. If the circuit is connected properly these readings will wander in the tens or hundreds of KΩ or higher range. What you want to watch out for is a zero reading at one of these terminals, which would indicate that something is mis-wired.

In this case, ± means that it will either be positive or negative, depending on how you connect your probes. Since it is a range, it seemed the clearest way to express this idea.
You are a bit out of range here. What was your incoming voltage? Were your transformer tests also reading above the suggested range?

The main criteria in choosing a meter is "can it measure what I need it to measure?"
Yours cannot.

[TurbOSquiD77]

I've just finished the assembly of my S.E.X. 3.0

How'd the build go? Finally put my order in earlier this week 

[troplin]

Regarding the *-values: I was a bit sceptical because the values seem rather low to me and all 4 of them converged to about 217Ohm.
Also because the voltages at the same terminals are also a bit off, I figured it might be helpful to include that observation.

In this case, ± means that it will either be positive or negative, depending on how you connect your probes. Since it is a range, it seemed the clearest way to express this idea.

Wait, does that mean that  I have to measure between H2 <-> H5, not two measurements: H1 <-> H2 and H1 <-> H5?
In that case, I've measured the wrong thing. (And you might want to explicitly write that in the manual, because the instructions say: "reconnect th black negative lead of the volt-ohm meter to the terminal H1")

You are a bit out of range here. What was your incoming voltage? Were your transformer tests also reading above the suggested range?

Unfortunately I didn't write them up, but as far as I remember, input voltage is slighly above 230 V (232 or so), and the transformer tests were in range.
PT measurements were (as far as I remember): First measurement (6.5V) was spot on, second measurement (175V) was a bit higher (186V maybe), but within tolerance.
I'll try to redo them tonight.

The main criteria in choosing a meter is "can it measure what I need it to measure?"
Yours cannot.

Now that you say it...   
Actually, I've bought it some time before I've recieved the Kit, when I didn't know the voltages yet.
(I know, I could have read the forum or asked, but well...)

[troplin]

How'd the build go? Finally put my order in earlier this week 

Mostly fine.
The manual is very detailed and leaves no questions.
I still managed to make a few mistakes and had to unsolder a few joints, but I always noticed it right away.

The most annoying point was stripping the wires. I have a cheap "automatic" wire stripper but the result wasn't always satisfying with the thin wires. For the black wire it was working ok, the red one was a PITA. Even if they seem to be the same except for the color. White was somewhere in between.
And for the CAT5 wires it worked sometimes and somtimes it just clipped the wire... 

So better wire stripper would have saved me some trouble.

Well, I've just googled a bit for a picture of mine and found this page: http://www.prc68.com/I/WireStrippers.html
It looks almost exactly like the third one and the comment is: "Adjustable wire stripper - don't bother with these."
I should have found that page earlier...
They're right, it's crap!

[fullheadofnothing]

Wait, does that mean that  I have to measure between H2 <-> H5, not two measurements: H1 <-> H2 and H1 <-> H5?
In that case, I've measured the wrong thing. (And you might want to explicitly write that in the manual, because the instructions say: "reconnect th black negative lead of the volt-ohm meter to the terminal H1")

No, you should leave your probe on the ground buss, but one terminal will read negative, and the other positive. Which is which will vary depending on exactly how the meter is connected. Since a range is specified with the same punctuation as a negative, which is confusing in the best of circumstances, and in this case in particular.

[troplin]

No, you should leave your probe on the ground buss, but one terminal will read negative, and the other positive. Which is which will vary depending on exactly how the meter is connected. Since a range is specified with the same punctuation as a negative, which is confusing in the best of circumstances, and in this case in particular.

I guess I still don't get it.
There are 4 terminals to be measured (H2, H4, H5, H7).
They are listed in pairs (H2, H5) and (H4, H7).

Does it now mean, that the terminals of the same pair should have opposite voltage? Or can they have the same voltage?

And how can that vary if the black lead of the voltage meter is connected to the ground buss?
Or is it dependent on how the PT is wired?

If the voltages are out of range, what should I check next?

[Natural Sound]

As Josh mentioned leave the negative lead from your voltmeter on the ground bus at all times while making these 4 voltage measurements. And all the other measurements for that matter.

The way I understand it goes like this.

H2 should read between 2.8V-3.2V It may read positive and it may read negative.
H5 should read between 2.8V-3.2V Should read the opposite polarity of H2.

H4 should read between 2.8V-3.2V It may read positive and it may read negative.
H7 should read between 2.8V-3.2V Should read the opposite polarity of H4.

If the voltages are out of range then come back and post your results.

I hope this helps.

[troplin]

The way I understand it goes like this.

H2 should read between 2.8V-3.2V It may read positive and it may read negative.
H5 should read between 2.8V-3.2V Should read the opposite polarity of H2.

H4 should read between 2.8V-3.2V It may read positive and it may read negative.
H7 should read between 2.8V-3.2V Should read the opposite polarity of H4.

That's also what I thought, at least initially.

But it could also be read as:

b) H2 can be either polarity, H5 must be the same polarity. H4 and H7 must be the same but opposite to H2 and H5

c) H2 and H5 han have any polarity. If they are the same, H4 and H4 must also be the same, if they are different H4 and H7 must also be different.

d) Any of the 4 terminals can have any polarity.

If the voltages are out of range then come back and post your results.

I hope this helps.

Well, I did (see my first post):
H2, H5: both 3.45V (should be +/- 2.8-3.2)
H4, H7: both -3.23V (should be +/- 2.8-3.2)

The absolute voltages are certainly a bit out of range, but I still have no definitive feedback whether the polarities are correct.
According to your interpretation they are not, but with interpretation b), c), and d) they are.

EDIT: And I still don't understand how this can be dependent on how you connect the multimeter (as Josh said), because there is no ambiguity there. But it must be dependent on something else, otherwise they could just list the correct voltages of all 4 terminals separately in the manual.

I've ordered a new multimeter yesterday to measure the higher voltages and will post a complete list as soon as it arrives.

[troplin]

Ok so I remeasured all voltages, including powerline and secondary voltages.
In the middle of my measurement, some kind of device was started outside of the building, changing the measurements considerably. So I took them again with the device running and standing still.


                        expected       measured       measure with "device" running
Powerline               230V           232V           227V-228V
PT Terminal 7 to 9      6.5V +/-20%    6.1V           6.0V
PT Terminal 11 to 12    175 +/-20%     182V -> 175V   180V -> 172V     (Voltages are higher after powering on, then dropping)


I'm not sure if the results should still be the same after installing the whole circuit though. I remember them being higher when I measured them initially.

And the voltage checks (except everything above 250V):

     expected      measured ("device" not running)
 2   65V-95V       86V
 3   15V-18V       18V
 4   0V            0.035V
 5   0V            0.0001V
 6   385V          (to be measured with new Voltmeter)
 7   400V          (to be measured with new Voltmeter)
10   380V          (to be measured with new Voltmeter)

16   65V-95V       95V
17   15V-18V       18V
18   0V            0.025V
19   0V            0V
20   385V          (to be measured with new Voltmeter)
21   400V          (to be measured with new Voltmeter)
24   380V          (to be measured with new Voltmeter)

H2   +/-2.8V-3.2V   3.45V
H4   +/-2.8V-3.2V  -3.20V
H5   +/-2.8V-3.2V   3.40V
H7   +/-2.8V-3.2V  -3.19V

[Natural Sound]

I'd wait for a reply from one of the specialists at bottlehead to reply but I don't see anything to be concerned about. A couple of your measurements are a bit high but not crazy out of spec. Re-measure everything with the new meter when it comes in, even the lower voltage stuff. I think you are going to be OK.

[Adrian]

As Josh mentioned leave the negative lead from your voltmeter on the ground bus at all times while making these 4 voltage measurements. And all the other measurements for that matter.

The way I understand it goes like this.

H2 should read between 2.8V-3.2V It may read positive and it may read negative.
H5 should read between 2.8V-3.2V Should read the opposite polarity of H2.

H4 should read between 2.8V-3.2V It may read positive and it may read negative.
H7 should read between 2.8V-3.2V Should read the opposite polarity of H4.

If the voltages are out of range then come back and post your results.

I hope this helps.

Actually, H2 and H5 connect to the same terminal (30; red) and should both read "+" volts.
H4 and H7 connect to the same terminal (32; black) and should both read "-" volts.

My 3.0 is a 120VAC version and my line voltage test done in the manual is 123VAC.  I continued with the build at page 31 because of my line voltage.
You said you thought your line voltage test was about 230VAC.  You probably continued your build at page 33.

Both of our line voltages are at about the same point in the voltage range for our different builds (123VAC & 230VAC)

My measurements of H2 & H5 are the same at +3.3VDC with H4 & H7 both at -3.14VDC
These voltages represent the DC value on both the + & - sides and added together represent the voltage going to the heater circuit.
My DC voltage is 3.3 + 3.14 = 6.44VDC.  My manual says the heater voltage should be 6.5VDC +/- 20% (5.2 - 7.8 ) (6.44 is pretty darn close; -1%).
Your DC voltage is 3.45 + 3.23 = 6.68VDC (still pretty darm close; +3%).
The manual allows a variance of +/- 10% when doing the final voltage check.

Don't fret over the heater circuit.

[Paul Birkeland]

Do you have the tubes installed for these measurements?

With the ground probe on your meter grounded, H2 and H5 will read a positive voltage, H7 and H4 will read a negative voltage.  If your probes are backwards, those readings will switch polarity.

[troplin]

Do you have the tubes installed for these measurements?

Yes, tubes are installed for all those measurements, also for powerline and secondary measurements.
Should I take them out for secondary measurement?

With the ground probe on your meter grounded, H2 and H5 will read a positive voltage, H7 and H4 will read a negative voltage.  If your probes are backwards, those readings will switch polarity.

Sure, but isn't that also the case for all other voltage measurements that don't have +/-?
After Adrians comment I realized that each H2/H5 and H4/H7 are directly connected and must have the same voltage. With that knowledge I suddenly understood the intention of the manual: H2/H5 is basically a single terminal, that's why it's on the same line. But that wasn't clear to at all when taking the measurements.
Anyway, consider the polarity issue solved now.

[Paul Birkeland]

Well, you're 5% high on the heater voltage. You could go back to the manual and rewire for the next highest line voltage, then remeasure. 

5% isn't going to hurt anything though.