I am playing around with my HP 339A and I have a question about reading the scales.
If i am on the .01% scale and I am reading .4 on the 0-1 portion of the meter, this corresponds to .004% correct?
Likewise if i am on the .03% scale and and am reading .8 on the 0-3 portion of the meter this corresponds to .008% correct?
Zc
If i am on the .01% scale and I am reading .4 on the 0-1 portion of the meter, this corresponds to .004% correct?
Likewise if i am on the .03% scale and and am reading .8 on the 0-3 portion of the meter this corresponds to .008% correct?
Zc
If I'm understanding you correctly:
1) Correct on the 1st account (.01% setting, if corresponding 0<THD<1 was (for ex 1.0) that would be a full .01%) ; but with a .4 reading : .01% x .4 = .004%THD
2)Wrong 2nd, same math....with a setting of .03% a reading of say 1.0 means a full .03%
but with a reading of .8 on (0-3range) is still .8 (units are .03% & you have .8units)
.03% x .8 = .024%THD
Look at it this way; each unit is 3xbigger in 2nd example and your multiplier is twice as big in 2ns ex. so 2nd answer is 3 X 2 =6 times larger than the 1st answer
So: .03% x .8 =.024%THD
Rule of thumb: never pull the % out of equation, just leave answer in %
Equation should have only one unit with a (%) sign on left side of '=', the other has to be a numeric multiplier (no units).....% X % really makes no sense (%)**2?
Common confusion....when yanks say 10% of 50% of (A quantity(no units))=10% of 1/2......same as 5% of quantity.
Charles.....
PS. Its certain if I'm wrong......we'll both know here very quickly !
1) Correct on the 1st account (.01% setting, if corresponding 0<THD<1 was (for ex 1.0) that would be a full .01%) ; but with a .4 reading : .01% x .4 = .004%THD
2)Wrong 2nd, same math....with a setting of .03% a reading of say 1.0 means a full .03%
but with a reading of .8 on (0-3range) is still .8 (units are .03% & you have .8units)
.03% x .8 = .024%THD
Look at it this way; each unit is 3xbigger in 2nd example and your multiplier is twice as big in 2ns ex. so 2nd answer is 3 X 2 =6 times larger than the 1st answer
So: .03% x .8 =.024%THD
Rule of thumb: never pull the % out of equation, just leave answer in %
Equation should have only one unit with a (%) sign on left side of '=', the other has to be a numeric multiplier (no units).....% X % really makes no sense (%)**2?
Common confusion....when yanks say 10% of 50% of (A quantity(no units))=10% of 1/2......same as 5% of quantity.
Charles.....
PS. Its certain if I'm wrong......we'll both know here very quickly !
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If you are reading on the 0-3 part of the scale you don't need any math beyond scaling by range. .8 on the 0-3 scale is .8 on a 0-3 range. You were correct.
This stuff is obvious for those old enough to have started with analog meters. I work with people today who have never seen an analog meter.
This stuff is obvious for those old enough to have started with analog meters. I work with people today who have never seen an analog meter.
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I lived in Dallas for 12 years myself so!...
I wasn't sure if the 0-3 scale was read directly or if you multiply the scale by the meter reading.
For example. If the scale is set to .03% I would naturally think that if the needle is pointing to the 3 on the scale, IE FS, that would represent .03%
If the needled pointed to the 2, that would be .02% and if pointing to the 1 would be .01% and likewise if pointing just below 1 at .8 that this would then be .008%
BUT, the manual which is NOT very clear and others have suggested that you multiply the meter reading by the scale knob setting. so that if the scale knob is on .03% and the needle is pointing to 2 on the 0-3 portion. then you multiply 2x.03 = .06% distortion.
and that a full scale reading, when the needle is pointing to 3 that would then = 3x.03 .09% distortion?
Its the difference of what full scale means. when on .01% is full scale .01% and when on .03% is FS .03% or .09%?
Zc
P.S. send me some BBQ!
I wasn't sure if the 0-3 scale was read directly or if you multiply the scale by the meter reading.
For example. If the scale is set to .03% I would naturally think that if the needle is pointing to the 3 on the scale, IE FS, that would represent .03%
If the needled pointed to the 2, that would be .02% and if pointing to the 1 would be .01% and likewise if pointing just below 1 at .8 that this would then be .008%
BUT, the manual which is NOT very clear and others have suggested that you multiply the meter reading by the scale knob setting. so that if the scale knob is on .03% and the needle is pointing to 2 on the 0-3 portion. then you multiply 2x.03 = .06% distortion.
and that a full scale reading, when the needle is pointing to 3 that would then = 3x.03 .09% distortion?
Its the difference of what full scale means. when on .01% is full scale .01% and when on .03% is FS .03% or .09%?
Zc
P.S. send me some BBQ!
You have it, but drop the Full Scale? Too, vague. Call it what it is; Scale Reading.
Yes :
3 that would then = 3 x .03%=.09% distortion
Which scale to use is a confusion point: For argument say the
The upper graduations (0-1) is like a base(10) vernier/evenly dividable by or a factor of 10 (1,2,5,10).
And the lower (0-3) is a base(10/3) vernier/evenly dividable by or a factor of 3 (1,3) Simply, Use it for all the '3' settings.
Evenly is the key word........ Just like a 'slide rule' its the same answer only different by the decimal place location.....
It's some significant figure Egyptian thing. Full scale!zig-zags?
CK
PS Ever have a Campisi's Pizza in D?
Yes :
3 that would then = 3 x .03%=.09% distortion
Which scale to use is a confusion point: For argument say the
The upper graduations (0-1) is like a base(10) vernier/evenly dividable by or a factor of 10 (1,2,5,10).
And the lower (0-3) is a base(10/3) vernier/evenly dividable by or a factor of 3 (1,3) Simply, Use it for all the '3' settings.
Evenly is the key word........ Just like a 'slide rule' its the same answer only different by the decimal place location.....
It's some significant figure Egyptian thing. Full scale!zig-zags?
CK
PS Ever have a Campisi's Pizza in D?
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Thank you for the explanation. At work i have a Tek AA501 that reads dist in direct % so that when it says 1% it's 1% no mucking about with calculators LOL!
yes to Campisi's, but preferred the lunch platter there. lasagna, spaghetti, meatball, ravioli all smothered in red dead meat sauce mmmmm! $9.99
Now the Pizza from prego's ohhhhhhhhhmmmm
yes to Campisi's, but preferred the lunch platter there. lasagna, spaghetti, meatball, ravioli all smothered in red dead meat sauce mmmmm! $9.99
Now the Pizza from prego's ohhhhhhhhhmmmm
Zc,
Cool,..... I have a AA501A opt1 myself paired with an SG5010 in a TM5006 that's got a PSU problem that I haven't got around to isolating yet. The programmable SG5010 is an odd match for the manual AA501 but it makes no sense to downgrade the SG (which is a top-notch ultra lowTHD unit) and I don't see myself springing for a prog. A5010.
I am curious how that pairing will compare to my fully restored/calibrated HP339A Opt-001 cuz the Opt-001 has the 2 additional .1mV & .3mV VM input ranges ......but became almost a $550. investment: about what I 'scored' all 3 Tek pieces for...
More to the issue of 'confusion' which woke me early!
...... Yea, HP defines the Opt001; "..... allows voltage ranges of .1mV "Full-Scale" to 300V "Full-Scale" verses 1mV 'FS' to 300V 'FS' ",
Accuracy is given as a % of the voltage 'range setting' which relates to a 10-fold increase in total accuracy for measurements taken below 30kHz.
.....In my mind this increase in 'accuracy' is actually only a 10fold increase in meter sensitivity (ie. 'sweep').
......All one has to do is read HP's tech-speck to be confused.
Now, I'm very accustomed to thinking of an analog VM's internal impedance being logically in units of ohms/volts measured ....higher impedance relating to less adverse measurement error due to the effect of the meter itself.....which seems more of a 'real effect' on accuracy than a 'FS' multiple ...........ENOUGH !
I believe it's time to sell my other HP339A and give the TEK's a go.
I will get back in touch for your insight on the AA501 which I'm assuming is paired with a SG501 or 505 ? Especially interested in what your preference will be. I don't need 3 THD sets, time to choose.
CK
Cool,..... I have a AA501A opt1 myself paired with an SG5010 in a TM5006 that's got a PSU problem that I haven't got around to isolating yet. The programmable SG5010 is an odd match for the manual AA501 but it makes no sense to downgrade the SG (which is a top-notch ultra lowTHD unit) and I don't see myself springing for a prog. A5010.
I am curious how that pairing will compare to my fully restored/calibrated HP339A Opt-001 cuz the Opt-001 has the 2 additional .1mV & .3mV VM input ranges ......but became almost a $550. investment: about what I 'scored' all 3 Tek pieces for...
More to the issue of 'confusion' which woke me early!
...... Yea, HP defines the Opt001; "..... allows voltage ranges of .1mV "Full-Scale" to 300V "Full-Scale" verses 1mV 'FS' to 300V 'FS' ",
Accuracy is given as a % of the voltage 'range setting' which relates to a 10-fold increase in total accuracy for measurements taken below 30kHz.
.....In my mind this increase in 'accuracy' is actually only a 10fold increase in meter sensitivity (ie. 'sweep').
......All one has to do is read HP's tech-speck to be confused.
Now, I'm very accustomed to thinking of an analog VM's internal impedance being logically in units of ohms/volts measured ....higher impedance relating to less adverse measurement error due to the effect of the meter itself.....which seems more of a 'real effect' on accuracy than a 'FS' multiple ...........ENOUGH !
I believe it's time to sell my other HP339A and give the TEK's a go.
I will get back in touch for your insight on the AA501 which I'm assuming is paired with a SG501 or 505 ? Especially interested in what your preference will be. I don't need 3 THD sets, time to choose.
CK
A 10X increase in sensitivity doesn't lower the distortion floor. The Tek soultion will prove to be a more useable pair on the bench. Unless your into writing test programs the programmability is pretty unimportant either way. If you get the matching scope in the TM5006 its a very nice little package,
at work we have the SG505 and the AA501's and it is a quick and easy way to do just about everything. my only gripe is that the level control on the SG505 is very hard to be precise with. it suffers from a lot of stiction. so if your trying to get to say 1% distortion, it will jump from .8 to 1.5% and there is no fine adjustment. I have been considering building an external attenuator for finer control.
I have pretty much decided i want a AA501 instead of the 339A. I like the smaller package of the Tek frame. But 339A prices have dropped like a rock and I cant afford a AA501 so I am going to have to wait for a swap meet bargain!
I have pretty much decided i want a AA501 instead of the 339A. I like the smaller package of the Tek frame. But 339A prices have dropped like a rock and I cant afford a AA501 so I am going to have to wait for a swap meet bargain!
Thanks Demian,
That's what my instinct or lack of quantitative faith has had me musing about this morning......reduction in distortion floor is synomous with reducing any test instruments error contribution to the total system error; in the units that are to be measured.
As presented sure didn't seem to equate directly, more empirically ...like a '10% off' sales pitch.
CK
That's what my instinct or lack of quantitative faith has had me musing about this morning......reduction in distortion floor is synomous with reducing any test instruments error contribution to the total system error; in the units that are to be measured.
As presented sure didn't seem to equate directly, more empirically ...like a '10% off' sales pitch.
CK
Zc, (I sent you a PM)
Just noticed your post. Well my TM5006 (GBIP-PowerModule) is quite larger and allot heavier than the HP-339a.
The level sensitivity issue you revered to should be a 'mute' point on the SG5010 with all its programming abilities.
Attached a picture below:
Also: Has anyone heard of this modification to a 339a?
Description of a 339a on EBay: I contacted the seller after the sale and curiously he wouldn't or couldn't elaborate:
TM5006 w/SG5010 & AA501A
Just noticed your post. Well my TM5006 (GBIP-PowerModule) is quite larger and allot heavier than the HP-339a.
The level sensitivity issue you revered to should be a 'mute' point on the SG5010 with all its programming abilities.
Attached a picture below:
Also: Has anyone heard of this modification to a 339a?
Description of a 339a on EBay: I contacted the seller after the sale and curiously he wouldn't or couldn't elaborate:
Quote:"Note that this unit has been updated with National Semiconductor LME49710 ultra low distortion operational amplifiers (0.00003%) in both the oscillator and analyzer sections. The result is a 5X performance improvement in the residual distortion capability."
?????
Charles?????
TM5006 w/SG5010 & AA501A
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