RR_Mel I used a #756 bulb with two alligator clips for years to check track voltage, multimeters came with a pretty good price tag in the 50s. I would bring my work Simpson meter home with me after work to work on my HO layout in the 50s. Mel Modeling the early to mid 1950s SP in HO scale since 1951 My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Built a Heathkit VOM in 1954. Lasted me thirty years before the D'Arsonval movement gave out. Only vacuum tube circuits then. 6.3 vac for filaments was about the lowest voltage other than batteries.
Never had a need to measure AC current.
Had VTVM's over the years but rarely measured DC current as the cases were metal and I believe connected to the ground probe. Used a plastic case VOM as we called them then.
Rich
Time's fun when you are having flies.
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
I have three of the Harbor Freight meters. Each gives a slightly different reading of the same track voltage. I just add up all the readings, and divide by three.
LION has more dead multimeters than him can shake his tail at. Maybe something LION cannot understand. Such as which range to look at, or where did that decimal point go anyway, and what is the base unit.
LION just sticks one claw here, and the other claw there and then counts the numnber of hairs that stand on edge.
Him gets along with out meters (that work) for 30 years, why do something gnu now.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Except at extremely low amp ranges - even the awesome Fluke 87V has a horrible burden voltage. Lesser Flukes are even worse. Critical in today's systems where so much runs on 3.3 and 1.2 volts - totally meaningless for model railroaders. But even the cheap meters are like 10 meg input impedence. Or so they claim - the ratings on those HF cheapies can be taken with a grain of salt. It might match if you compare it to an expensive meter measuring a 9V battery or something, but the real question is, how long will it stay like that?
All depends on what you are using it for. Train stuff - one place after the decimal point is more than accurate enough to see if you have power everywhere or check the stall current of a loco. All that extra stuff can just be confusing to someone not used to the more sophisticated tools. One point - if you read the specs (and if they aren't provided, in detail - you're dealing with a 'cheap' meter), even most True RMS meters aren't terribly accurate with a square wave at DCC frequency evn if they have outstanding DC voltage specs and even sine wave AC RMS ratings. Building the simple little circuit above is far cheaper than buying a $400 meter to get effectively the same results if you really need to be that accurate with the track voltage reading.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
As an electronics professional, I use Fluke meters at work. But for the simple needs of the modeller, those cheap harbor freight meters ought to work.
The capacitor test on hand meteres can only tell you the value of the cap, but cannot tell you if the cap is electrically leaky or has elevated "ESR". So OK for sorting out unknown values, but less useful when troubleshooting. I rarely have to measure caps. At the very low voltages on railroad layouts, leakage is rarely an issue anyway.
Low impedance meters usually refers to the old analog meters, the ones with a moving needle. Most electronic digital meteres will not load your circuits.
Make sure it has:
Volts (DC and AC)
Amps (up to 10 amps)
Ohms
Extras:
Continuity Testor: A lot easier to listen for a beep while holding probes on a tiny part..good for locating shorts or bad/intermittent connections as the beep will become "static" sounding if the connection is not solid.
Capacitor Reading:...good for testing if your cap is still good.
Backlight: with obvious reason
Kickstand: Sitting it up is a lot easier to read.
Alligtor Clip Ends: Makes it a lot easier to measure voltage/current on wires.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
DCHOAny suggestions?
As others have stated, you don't have to get very sophisticated with your choice of meters. I will suggest, though, is to look for one that has an audible continuity checker.
I have used this option countless times and it is handy to listen for the "beep" while "ringing-out" circuits rather than having to actually watch the meter. This is usually marked on the selector by a small "speaker" icon. I find it particularly handy when isolating motor mounts on brass engines, wheel insulation and orientation and Tortoise wiring to frogs.
Check that the meter you are interested in has this option.
http://www.amazon.com/Volmate-Digital-Voltmeter-Ohmmeter-Multimeter/dp/B00TWTLWT8/ref=sr_1_3?s=hi&ie=UTF8&qid=1453228430&sr=1-3&keywords=multimeter
You can see the selection at the "5:30" position on the dial of the above example.
Just my 2¢ — Ed
My meters were about two to three dollars each at the time.
Made test probes about three feet long. Also made a set with flea clips for digital circuits. Bought spare fuses at Radio Shack.
I made an adapter to read DCC voltage but found it was not necessary as the readings on the AC scale are close enough.
I have four of these. They all read about 13.6 VAC with my NCE Power Cab. About the same at the club with a NCE Power Pro.
With a couple three terminal SMT devices and a few passive components, they read DCC current on the meter DC 20 MA scale.
http://www.trainelectronics.com/Meter_Workshop/index.htm
http://www.trainelectronics.com/Meter_HF/index.htm
I would guess the company that makes them is in China. You can find these meters on ebay also. Sometimes different colors or meter face slightly different. Some still have a little socket for checking transistors that have wire leads. Very old school.
Rugged meters. Compared them to an expensive meter and readings from my Oscope. This is not rocket science.
I've been using the cheap/free HF meters for model railroad stuff for years. Plenty good enough. Just don;t go trying to measure household voltage with them, they have zero protection and can in some cases literally blow up in your face. No worries with DC and DCC voltages used on train layouts though.
Coincidently I just won another fancy Fluke benchtop meter on eBay yesterday, so now I have two fancy meters (both somewhat old - the one I have is an 8012A from the early 80's, this new one is a Fluke 45 dual display from the late 80's/early 90's. Dual display means it can show two measurements at the same time, like volts and current, or ac volts and frequency, or ac and dc volts - which would have been interesting with the old pre-dcc command control systems that superimposed an ac control signal on a steady dc power).
I'll still be using the HF ones to check layout wiring.
I picked up a nice digital multimeter (DMM) at Radio Shack a few years back for $20. It works quite well and even comes with a temperature probe.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Places like Harbor Freight have them for a few dollars, and they will do 99% of what you need for this hobby. I am still using an old Radio Shack meter I've had for 30 years. If you're doing serious engineering work, yes, get a quality meter, but if all you need is to measure the voltage across your tracks or buzz out a connection, a simple, cheap meter will do the job.
It takes an iron man to play with a toy iron horse.
First: What Chuck said: try the Model Railroad forum.
To start, any digital meter for around $20 or $30 should do the job. The cheaper ones may have a lower input impedance, which is OK for power circuits, but will load down some electronic circuits. As you go up in price, you're paying for features such as auto-ranging (which I don't care for) and more functions such as capacitance, frequency and temperature measurements. Look at
http://www.radioshack.com/diy-test-and-meter-equipment-multimeters
http://www.mcmelectronics.com/browse/Electrical-Meters-Testers/0000001239
and if you want to be overwhelmed,
http://www.digikey.com/product-search/en/test-and-measurement/equipment-multimeters/2294086
One more thing: If your digital meter indicates a low battery, change it soon. It will continue to work, but may give inaccurate readings.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
This would be a good question to ask in the Model Railroader Electronics and DCC forum. It's located about halfway down the page from here.
I'm still using a multimeter I bought in Tokyo about half a century ago, so I can't help with data about current products.
Chuck
I need to purchase a multimeter for my HO layout using DC and DCC. Any suggestions?