Is this a good DMM for $70 ???

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If accurancy is no big deal I would say that don't buy an unneccessary expensive DMM.

I would say that a 30 USD can be perfect for you unless you want high mechanical qaulity.

I have used Fluke 77 for years, a true work horse with fast auto ranging and very little power consumption (one battery every 12-18 months).

Rescently I bought a maximized APPA 305 but this thing eats batteries! Also slow autoranging! But I had chosen Fluke the price would have been x1.5- x3! APPA 305 costs here in Sweden 280 USD and Fluke costs 400+ USD.
 
Here are some things to consider about DMMs...
1) Digits- 3 is somewhat limited- 4 is OK, 5 is great, 6 is overkill for most applications.
2) Features- inductance is almost useless for audio work. Capacitance can be useful if you have a bunch of unmarked parts, otherwise it is not all that useful. It isn't usually very accurate unless you have a fixture and proper cable to connect to the meter.
3) Battery life- this can be a big deal, but the catalogs don't tell you what the life is (because it will vary depending on how you use the meter) so you just have to ask around a lot.
4) Settling time - some meters seem to take forever to give you a stable value, others are quick. Unfortunately, this varies from model to model, even in the same manufacturer's line.
5) an "analog" or bar-graph type display is useful for making adjustments (but an analog VTVM or similar device is even better).
6) Other goodies- like communitions to a PC and data logging- can be useful for moniotring long term changes in temperatures, bias levels, etc. I understand Radio Shack has a couple meters out with this sort of capability, as does Fluke.

I say spend the extra dough and get a Fluke. These days most models have a lifetime warranty (which is one of the things that pushes up the price a bit). The first time you have to replace a meter because repair cost is about the same as purchasing a new one (and it usually is) you'll kick yourself for not getting the one with lifetime warranty up front.

In my many years of doing electronics I have learned two things:
1) Never buy cheap tools. They will break your heart every time.
2) Never buy components at retail unless you have an immediate need for them. Like computer software, the prices always drop over time, and better ones are coming out all the time.

MR
 
I got Fluke 97, got Fluke 87, but mostly find myself using cheap Wavetek DM15XL. For my needs I don't see much difference between all those meters. Actually, I don't like to use Fluke 97, because it's too big and too complicated (I used it only as a scope). I recommend to buy a cheap meter and try it out, if it's not up to your needs, buy second one, more ealaborate. Whenever I test my new amp for a first time I always need 2 meters so it won't be a lost or wrong decision on your side.;)

And inductance mesurement capability is very important for speaker building.
 
Capacitance can be useful if you have a bunch of unmarked parts, otherwise it is not

Or want to match caps for filters, crossovers, RIAA, cable capacitance, ect. I have two capacitor meters and use them alot. I like an inductance meter for measuring transformers windings also. you can make a test jig with banana plugs and alligator clips with very low stray parasitic capacitance and inductance. More than adequate for audio frequency parts.

Ren
 
bbaker,
agree with the others, this instrument should do fine. But maybe you are better on on with a 4 digit meter not having capacitance and inductance.

I owned an Escort digital LCR meter costing about US$260. It showed capacity quite reliably, it sported weird behaviour concerning the measured Q or damping value, worse, measurements of the identical cap showed different Q values depending on the manually selected range. Measured inductivities were nothing but rough guesses. Its main vitrtue was measuring electrolytics quite accurately and reproducably.
I lost trust in the instrument and sold it. Today i do not trust cheap handheld devices including my Fluke 123 as far as capacity and inductivity is concerned.

Maybe your meter should have less fancies and do those fancies fine. For instance. Our local surplus shop sells a combined analog and digital meter; it has a 4 digit readout and a real analogue voice coil meter. You have the DVM for exact reaqdout and the needle for observing continuous parameter changes like rsing currents where the slow digital thing drives you nuts and tells you lies.

For L and C nothing i can afford beats the ESI 250D impedance bridge i got on ebay for $100. If i would be you, i would buy a decent combined instrument like described above and a cheap impedance bridge which should have a Q/damping compensation with readout. How high the Q or how low the damping is tells you directly how good the component, choke or cap, is for audio. My best caps like MKV show almost zero damping.

All,
i love my Fluke 123, just not for measuring Cs. Okok, i am happy it has it if i am anywhere and i have the Fluke only. It is an industrial scope meter, in fact a small oscilloscope. It is myy most used instrument, it is soooo convenient. But my old trusty analog Metrawatt Unigor i use almost as much.
The Fluke 80 series are good and reliable, but they waste battery like hell.
If i had to buy a DVM today, i would stick to the fluke 70 series. Maybe not a bad idea to buy a Fluke 77 used instead of buying some crap new.
 
"If I had to buy a DVM today, i would stick to the fluke 70 series. Maybe not a bad idea to buy a Fluke 77 used instead of buying some crap new."
Brad, I second that - I've used a '77 for 20 years and I find that I just can't be bothered with anything else.
The '77 is the top of the range of the '73, '75, '77 series and includes a sample and hold function that I very rarely use.
The '75 is the same meter except that it misses out on the S/H function, but this can be enabled by fitting a single link on the pcb.
If you hunt around you can likely find one economically, and you will always be pleased with it.
Oh BTW, the '75 & '77 have an audible continuity/diode junction test function that is second to none - for me this feature sets this meter way apart from lesser ones.

Eric.
 
If you buy a cheap DMM, you will probely get the chip ICL7109 or similar and this chip is very good. In fact almost every dual-slope ADC is good by nature. What you pay for is the case and the stability. For hobby it doesn't matter really which type you buy. Go for a descent cheap model which have the features you like.

My DVM830 Velleman made by Tjing tjong in China or somewhere works allright but I don't assume that the rotary switch will last very long, as with the Fluke, but hey I got for free from a magazine.

I have checked this rubbish DMM agianst my 0.025% DMM (newly calibrated) and it's reading is surprisingly good.

I suspect that you don't need 4 1/2 figures (if we talk accurancy) but it can be nice sometimes when you want to see a trend or change.

Still my Fluke is a work horse, no nonsense, top quality. Allways there for you.
 
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Err, $70 is entirely too much for a non auto-ranging dmm. You can buy a Fluke 110 for $99 with the nice little shock casing new. They are tough, and can do true RMS readings, and are auto-ranging. You can pick up just about any equipment on ebay for much less then retail, none the less.
 
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