The used ones are sold... 
Okay, i might get something the next days and a nice fluke 187189 later...
This one ?
http://www.fluke.de/comx/show_product.aspx?pid=26864&product=HMA&type=2&locale=dede
Mike
Okay, i might get something the next days and a nice fluke 187189 later...
This one ?
http://www.fluke.de/comx/show_product.aspx?pid=26864&product=HMA&type=2&locale=dede
Mike
Hi Mike,
Those ones would service you well. Also have a look at the 87V. I haven't compared these myself. The new ones are "closed case calibration". This is a huge advantage. Case dimensions affect the AC readings enormously.
So, if you purchase a new one, it's worthwhile to get the calibration report with data. You can use this to correct some readings. I will also say that they will then optimize the calibration. You want that. They may charge $40~60 CDN to do this, maybe more these days. For closed case it should be less to be honest with you.
Let me know how you make out.
-Chris
Edit: Mike, depending on how much later you plan to get a good one, it may be worthwhile to simply finance the one you want. Bank loan style rather than load sharks
.
Those ones would service you well. Also have a look at the 87V. I haven't compared these myself. The new ones are "closed case calibration". This is a huge advantage. Case dimensions affect the AC readings enormously.
So, if you purchase a new one, it's worthwhile to get the calibration report with data. You can use this to correct some readings. I will also say that they will then optimize the calibration. You want that. They may charge $40~60 CDN to do this, maybe more these days. For closed case it should be less to be honest with you.
Let me know how you make out.
-Chris
Edit: Mike, depending on how much later you plan to get a good one, it may be worthwhile to simply finance the one you want. Bank loan style rather than load sharks
.
Hi Al,
I do agree otherwise. I've picked up some old Fluke meters, lesser models. They perform well and I know the readings are correct (after having optimized them )
-Chris
Only if you can trust the readings, otherwise they are worse than not having them. Don't trust the specs on the package. Often they can not keep that tolerance even.
I do agree otherwise. I've picked up some old Fluke meters, lesser models. They perform well and I know the readings are correct (after having optimized them
)-Chris
Hi -
Cheap DMMs - typically the specs are ok, BUT they often do not tell you how much power the DMM runs on. Had one here at the uni that worked fine but would go through the 9V battery like... well y'know.
The other comment is- the more functions it has on the selector, the less reliable in the long run - may be because of the very small contact surface. After the meter has been used for a time the contacts go bad - my unit has problems on the low-ohms scale now, and you sort of have to push it against the detent to get it to zero...
Cheers!
Clem
ps: MikeB - Mastech sold here too - but not as a german brand... China-made stuff... could be the same manufacturer really. I echo Chris' suggestion - get a Fluke if you can. It's the only brand that seems to reasonably survive the student abuses here...
Chris,
Re Agilent - is the quality still as good as when it was 'HP'?
Cheers!
Cheap DMMs - typically the specs are ok, BUT they often do not tell you how much power the DMM runs on. Had one here at the uni that worked fine but would go through the 9V battery like... well y'know.
The other comment is- the more functions it has on the selector, the less reliable in the long run - may be because of the very small contact surface. After the meter has been used for a time the contacts go bad - my unit has problems on the low-ohms scale now, and you sort of have to push it against the detent to get it to zero...
Cheers!
Clem
ps: MikeB - Mastech sold here too - but not as a german brand...
China-made stuff... could be the same manufacturer really. I echo Chris' suggestion - get a Fluke if you can. It's the only brand that seems to reasonably survive the student abuses here... Chris,
Re Agilent - is the quality still as good as when it was 'HP'?
Cheers!
Hi Chris,
Cranky stuff. Drivers that refuse to work with their own equipment sometimes (had the a very bad experience with an HP scanner, SCSI interface, for example). Or an example of bloatware - they actually use a java-based server to give you status info about your printer, so you wind up with this huge set of resident programs just because you have a laser printer.
Cheers
Clem
edit: here's another one - our Agilent logic analyzer box refuses to work on some of our computers - firewire interface.. Still scratching our heads why. Then again, maybe it's partly because of Windoze...
Cranky stuff. Drivers that refuse to work with their own equipment sometimes (had the a very bad experience with an HP scanner, SCSI interface, for example). Or an example of bloatware - they actually use a java-based server to give you status info about your printer, so you wind up with this huge set of resident programs just because you have a laser printer.
Cheers
Clem
edit: here's another one - our Agilent logic analyzer box refuses to work on some of our computers - firewire interface.. Still scratching our heads why. Then again, maybe it's partly because of Windoze...
Hi Clem,
I owned a few HP laser printers. I use a print server now. But the only issues I ever had with scanners or printers (or any other device) turned out to be driver, or OS problems. I even had a driver for a NIC that wouldn't work with OS/2 (I picked the only address it didn't like), but IBM called back in a day with the fix. Then called back a week later to make sure it was all good. IBM
uSoft never admits to a problem unless you prove it to them beyond doubt.
You've only had a glimpse of my uSoft issues. I dislike them intensely these days.
I think the java based program was an attempt to have a portable interface that was proven bug free (so uSoft couldn't whine to them). Newer interfaces are bound to have trouble under most OS's, but be more persistant under ......... you guessed it! uSoft.
-Chris
I owned a few HP laser printers. I use a print server now. But the only issues I ever had with scanners or printers (or any other device) turned out to be driver, or OS problems. I even had a driver for a NIC that wouldn't work with OS/2 (I picked the only address it didn't like), but IBM called back in a day with the fix. Then called back a week later to make sure it was all good. IBM
uSoft never admits to a problem unless you prove it to them beyond doubt.
You've only had a glimpse of my uSoft issues. I dislike them intensely these days.I think the java based program was an attempt to have a portable interface that was proven bug free (so uSoft couldn't whine to them). Newer interfaces are bound to have trouble under most OS's, but be more persistant under ......... you guessed it! uSoft.
-Chris
So could that mean that someone could increase their performance by simply sawing their heatsink in half? And if They used a bad saw, then would the jagged cuts increase surface area and keep their transistors slightly (but significantly) cooler than with a cleaner cut? Also, I have thought before that someone could take a bare-bones heatsink (no special coatings and stuff), and scratch it hardly with coarse steel wool until it was very rough so that the surface area increased significantly, which I believe would cause a substantial increase in performance. Think that this would work well?
Just some spontaneous thought combustion, that's all.
BTW: Mike, since you are a programmer, think that it would be possible to write a Java program that calculates the THD of an LTSpice or FFT file? This would earn you even more respect - writing utilities for sims!
You have said that you have no experience with LTSpice, though...
Just some spontaneous thought combustion, that's all.
BTW: Mike, since you are a programmer, think that it would be possible to write a Java program that calculates the THD of an LTSpice or FFT file? This would earn you even more respect - writing utilities for sims!
You have said that you have no experience with LTSpice, though...
Hi keantoken,
Most amplifier manufacturers do indeed keep their heatsinks separate for each channel.
As for the jagged edges - well that's something you may want to try writing a simulation progam for...
- jagged edges and roughness due to sandpaper --> increase in surface area
- otoh, what about air flow --> jagged eges = turbulence...
Rough-surfaced heatsinks aren't new - the CPU fans a couple of years ago had that, i.e. coolermaster. The actual term they used slips my mind at the moment though... not sure if the roughness was machined or acid-etched, or stamped..
Most amplifier manufacturers do indeed keep their heatsinks separate for each channel.
As for the jagged edges - well that's something you may want to try writing a simulation progam for...
- jagged edges and roughness due to sandpaper --> increase in surface area
- otoh, what about air flow --> jagged eges = turbulence...
Rough-surfaced heatsinks aren't new - the CPU fans a couple of years ago had that, i.e. coolermaster. The actual term they used slips my mind at the moment though... not sure if the roughness was machined or acid-etched, or stamped..
Yeah, more jagged edges will create turbulence, but it should still work better if you have a fan. BTW, What does the group think about having a CPU fan in my SymAsym system? Should I try to keep air circulation away from the components? Would air circulation cause hissing/increased noise? I would also think that it may also cause sensitivity to outside noises because of the vibrations in the air (or does that happen anyways?).
BTW, Mike, I may have an idea why SymAsym is so quiet: since noise (that isn't generated by the components) is applied equally to all exposed leads, it doesn't affect the operation of the LTP(s). could I be right?
BTW, Mike, I may have an idea why SymAsym is so quiet: since noise (that isn't generated by the components) is applied equally to all exposed leads, it doesn't affect the operation of the LTP(s). could I be right?
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