Silly question?
I picked up one of these Amprobe AM-3E Multimeter Analog Amprobe AM-3E AM 3E AM3E for $6.05 at a garage sale (why .05? I don't know.
). It looks brand new, but it's probably 15 or more years old.
So do multimeters degrade with age? and are the specs on this one good enough to do some headphone amp diy?
I picked up one of these Amprobe AM-3E Multimeter Analog Amprobe AM-3E AM 3E AM3E for $6.05 at a garage sale (why .05? I don't know.
). It looks brand new, but it's probably 15 or more years old. So do multimeters degrade with age? and are the specs on this one good enough to do some headphone amp diy?
It's possible that it needs to be readjusted or calibrated. This is easy to do with the help of someone who has a multimeter which is trusted to be accurate (a relatively new Fluke or something like that). Other than that, it will continue to work just fine as long as you don't break it.
Good enough to do some headphone amp diy? I can't see why not!
Good enough to do some headphone amp diy? I can't see why not!
Given it's an analog meter as long as it has not been abused it should last indefinitely. (Also you need to replace the batteries periodically, and before they leak.) Checking calibration against a known accurate meter and making some adjustments if necessary is a good idea.
I have a 50yr old Simpson 260 multimeter I bought at a hamfest last fall for $10 which with just a little TLC it now works just fine and is reasonably accurate within the context of what it was designed to do.
I have a 4yr old Keithley 2002 (LED display) purchased new and a much older FLuke 8050 (LCD display) which both work fine. The Keithley is one of the flagships of lab grade DMM's and has a price to match, I was lucky to be able to get it.
I also have a variety of cheap, expendable meters which are much less robust electrically than the above 3 and also in most cases are much less accurate. (I never use them for critical measurements of any sort.)
I have a 50yr old Simpson 260 multimeter I bought at a hamfest last fall for $10 which with just a little TLC it now works just fine and is reasonably accurate within the context of what it was designed to do.
I have a 4yr old Keithley 2002 (LED display) purchased new and a much older FLuke 8050 (LCD display) which both work fine. The Keithley is one of the flagships of lab grade DMM's and has a price to match, I was lucky to be able to get it.
I also have a variety of cheap, expendable meters which are much less robust electrically than the above 3 and also in most cases are much less accurate. (I never use them for critical measurements of any sort.)
Last edited:
I have a FLuke hand meter - a model 75 - I have had now for close to 30 years. It has been used daily all that time, and while it is shop bound now, it was used in field service for the first half of its life, often tossed in my Jensen toolbox in the cargo hold of an airliner. Display still good, works fine.
I have an old Eico VTVM I built from a kit 50 years ago. I rcently dug it out, I plan to clean it up and put it on the bench just for old times sake. I have no doubt it still works, but a battery was left in it, corroding that area, so the resistance function will need work. But no reason it won;t work another 50 years, though I won;t be here to see it.
I have an old Eico VTVM I built from a kit 50 years ago. I rcently dug it out, I plan to clean it up and put it on the bench just for old times sake. I have no doubt it still works, but a battery was left in it, corroding that area, so the resistance function will need work. But no reason it won;t work another 50 years, though I won;t be here to see it.
Don't know how old my Fluke 73 is, but I bought it new when they first came out. It gets used weekly if not daily. Display still good, calibration has never drifted and I doubt it's used more than 3-4 batteries in it's entire life. A "friend" sheared off the plastic pin that stops the knob so I installed a little metal pin. That was probably a decade or so ago.
CH
CH
I bought a "lot" of HP 400-series meters a few weeks ago, and have one which is NIB -- but I still use my Eico 222 pictured below -- I purchased it in (I think) 1967.
An externally hosted image should be here but it was not working when we last tested it.
I don't know what happened to my VOM of the era. I think my brother got it when I went to college.
Doesn't really matter since they're dirt cheap, and they all have connections which have been made = connection that can fail.
5 of them [<20 dollar value] should last pretty good, I like having a come-spare-a-tor, having 2 means it can be determined if they agree.
Battery failure [try new one]
Flexible probe cable/probe continuity breaks [fix it btnew]
Probe jack/PCB weld break [possible re-flow of solder]
Screen/circuit/other [there's not much left to work or fail]
^Seems to be the order of frequency of failure points.
5 of them [<20 dollar value] should last pretty good, I like having a come-spare-a-tor, having 2 means it can be determined if they agree.
Battery failure [try new one]
Flexible probe cable/probe continuity breaks [fix it btnew]
Probe jack/PCB weld break [possible re-flow of solder]
Screen/circuit/other [there's not much left to work or fail]
^Seems to be the order of frequency of failure points.
I use a Fluke 73 and a 1980ies vintage HP3478A. The 73 I've had since it was new in about 1990. The HP I picked up on eBay recently and it checks out good versus the newer, calibrated meters we have at work. The Fluke has the 'broken knob' problem as described earlier, which makes it possible to turn the knob past the "OFF" position. Not really a big deal, but I should look into installing a pin... All I've done to it has been to replace batteries and after about 20 years of use, I calibrated it. I think it was out by less than 10 mV on the 1 V range.
~Tom
~Tom
i had a fluke87 that i bought fromoneof the members here, came in with some segments almost impossible to read....
so what i did was dismatle the boards and diplay and cleaned the contacts with isoprophyl alcohol using cotton buds....
now my meter looks good as new....
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.