We are spoiled with multimeters today. Even the cheapest meter you will get these days is almost surely digital with a tremendous input impedance. But a few decades ago, meters were almost always analog affairs. To make a precise measurement, you needed a mirror under the meter to ensure you read the needle correctly. Moreover, a common meter wouldn’t have that high of an input impedance. If you spent more, you could get a VTVM and, later, one that used FETs to provide high input impedance. [Peter AA2VG] just picked up a vintage Micronta FET volt-ohm meter to join some of the other new and old meters in his shack. You can check it out in the video below.
[Peter] already has a Simpson and a more modern Fluke meter. The Simpson, however, doesn’t have a tube or FET amplifier. The Fluke is nice, but there is something about the needle on an analog meter. If you aren’t old enough to remember, the Micronta brand was a Radio Shack label.
The teardown and repair started just before the 11-minute mark. There were two obviously burned resistors and a leaking battery—an easy repair to put this meter back into service.
If you weren’t a fan of Radio Shack, maybe Heathkit was more your style. While we like our digital meters, many people still like to use analog instruments for some tasks.
Simpson 260 6xlm for the win!!
Can confirm. Own one and you’ll have to,pry it from my cold dead hands.
Also working to get an HP 410C VTVM repaired and operational again.
260 with a roll top case. It was my grandfather’s go-to forever until he gifted it to me about 40 years ago. I guess I never really thought of it as an antique until just now.
That reminds me, I need to get some new leads for the 260. Ya just can’t count on anything to last anymore.
I got some nicely made ones off Amazon. Yeah, it’s a bit of a crapshoot, but these seem pretty well made
https://www.amazon.com/KAIWEETS-Electrician-Alligator-Multimeter-Electronic/dp/B07SD3L9HR
Double check before you buy any leads The model number of the Simpson 260. If it is a 260-7 or a 260-8, you will need reverse banana plug leads. They’re not the normal leads you’re used to seeing. Do not buy the Simpson branded leads as they will deteriorate. They’re made of natural rubber. Go to www probemaster.com.
Go for the 8000 series probe. It will cost you $24.50 versus the almost $50 for the Simpson. These are made out of silicone and will outlive you and your grandchildren. They’re much more comfortable to hold and the reverse banana jack fits perfectly. There are two millimeter adapters you can buy for the cheap Chinese probes but they don’t fit right a little loose and wobbly. Don’t waste your money I’ve already done that for you. 😁.
p.s. The probemaster leads are made in the USA too.
Avo Meter Model 8 FTW!!
The nice thing about analog is that you can easily see when you have line noise in the signal.
not exactly sure about line noise (you mena 50 or 60Hz mains?) but ~15-20 years ago I was able to repair a friends laptop PSU *just* because of an analog meter.
It’s voltage output looked fine without load and with the laptop connected I may have seen small *glitches* on my digital multimeter but when I tried an old analog meter from my dad it showed nice significant and repeating dips in the voltage output.
If I remember correctly a choke had physically broken loose – one resoldering and a bit of hotglue later it was fine again.
I think [Dave Jones] of EEVBlog debunked that one some time ago. And many other analog meter myths.
I’m surprised all modern digital meters don’t have dual display of the AC component when measuring DC, or a little 1khz(Not gonna see Mhz on an analog meter) scope that constantly auto-adjusts.
You’d think multimeters would actually be a bit more advanced than they currently are.
Be aware when you buy a *modern* analog multimeter today.
I got a Voltcraft VC-5081 a few years back and not a single measurement option works without batteries.
This thing won’t measure voltage or amperage without it’s 9V battery. :-(
Here in the UK AVO meters were the thing – built like a tank and with a mechanical cut out triggered by the needle itself going off-scale. As a teenager in the 1970 I longed for one but they were way above my paper-boy budget; now I have one from the 1950s *and* one from the 1970s and it amuses me to use the correct period meter when repairing period electronics.
https://hackaday.com/2020/02/16/amp-volt-ohm-meter-model-8-mark-iii-from-the-1960s.
I have two Avometers inherited from my SK friend. One dates from 1969 from when he started work. The other is a tropicalised version with NATO part numbers on it.
I love using them both. There’s just something about using an analogue meter. I also have several digital ones that actually have more uses than an Avo but I just love Avometers from the smell inside to the 15v batteries.
Yeah, AVO. The shop I apprenticed at in the 70s had two or three. There’s still one Micronta analog VOM on my bench.
The Fluke 77 digital meter (and imitators) had a fast-changing bargraph, which gave some analog-like feedback.
I would like to see the highly unreliable, wiper contact that rotates over a pcb trace selector switch idea put to rest. Almost every meter I’ve ever had used this and failed at some time because of contact dirt, bent wipers, broken traces.
I made a simple analog meter once where you change the range by plugging the lead into different banana jacks. No rotary wiper needed.
There was a polish meter that operated like that. It was made in 60’s, I think. It was build that way because it was cheaper and simpler than using a range switch…
The french company Metrix used this on their 450-460 series multimeters in the 1950s-60s. A row of plugs for amps, another one for volts and an additional one for ohms. A rotary switch was still used to switch between AC/DC/ohms but it made it way cheaper to make.
I still have my Microtest 80 which works like this. Great little meter
This is quite interesting, from the historical point of view. And analog meters have their charm. But there is no practical reason to use them anymore. The “cheap” ones are not cheap, nor that great. Used ones are either a bit expensive or have some problems, and anything they can do, a DMM can do better. Besides that, an entry level DSO can show intimate lives of all sorts of signals, and is much more versatile…
As for that voltage multiplier, I designed one that has selectable gain from 100:1 to 100k:1, based on pair of SSM2019 ICs. Currently I’m working on 80dB gain wideband active oscilloscope probe with high-impedance input, that would be cheap to make…
On the contrary Urgon, the old meters do have many uses in the modern world. I earlier saaid the Simpson 260 6xlm for the win. Why or where would you want to use an analog meter? The Simpson 260 has two batteries that make up the ohms circuit. One is a 1.5 volt and the other is a 9 volt. The 1.5 is used only on Ohms x1 and the 9 volt is used on the other Ohms ranges. Modern high impedance meters typically use less than 1.5 volts for measurement. If you use high impedance and low voltage I wish you the absolute best at finding bad grounds especially in automotive environments. The 9 volts plus low imput impedance make easy work of finding these bad grounds. I came from an automotive field and moved into HVAC/R. When the younger guys can’t find a bad ground with their digital meters I come in and save the day with the Simpson. This is but one example but there are other places they come in handy.
I have 6 DMMs, and one AVO. I never use AVO. All of my DMMs have different quality of continuity test, which let me check for, well, continuity. By using auditory feedback it makes much easier to locate any shorts or unreliable connections.
The main drawback of AVOs is their “display”. It’s good enough for volts or amps, but resistance ranges are logarithmic, which makes upper ends of ranges quite useless for accurate measurement. Even V/A ranges are only as accurate as the sight of the user. DMMs do it better, and Aneng AN870, my best handheld meter is far more accurate than even the best AVO. And it’s far cheaper than most of them.
There is only one analog meter that is superior to most of digital ones: a specific type of ammeter, that actually measures temperature of resistive element that makes it accurate from DC VHF. The only relatively cheap way to measure RF current for RF requires a DSO, a proper setup and a tiny bit of math…
“Why or where would you want to use an analog meter?”
Due to the sample time on a DMM, an analog meter is more responsive to changing values. If anyone knows of a DMM that isn’t extremely expensive that has a FAST MIN/MAX (NOT just MAX) function, please let me know.
Yes. Sometimes there’s more information in watching a needle bounce than a digital readout flickering like a Vegas slot machine. I like having both around.
“As for that voltage multiplier”
The Micronta I bought in the Fall of 1977 has a “Range Doubler” switch, but when used for voltage reading, the ohms/volt is halved.
The voltage readings from meters with ultra-high input impedance can’t be relied on. Once the probe tip leaves the conductor being measured, the voltage floats at the same level or is influenced by stray fields. The user doesn’t always know the probe slipped off. This can’t happen with the old stuff; it always returns to zero.
I never had a false voltage reading on my DMMs due to poor contact or contact slippage. The standard impedance of 10Mohms prevents that. Even FET input AVO should have an input resistor to keep FET from going crazy with stray fields. That’s just common sense in design. Even when designing a higher impedance probe (up to Gohm range), there is always biasing resistor network (and some other circuit trickery) to protect the input…
I beg to differ OP, the electronics markets in Shenzhen are swarming with analog meters to easily visuals various characteristics of the DUT (boot sequence for example)
Why then western civilization uses DMMs almost exclusively? Only people who still use them are those who never had a decent DMM. The same people defend analog oscilloscopes calling DSOs “useless junk”, and still use transformer-based soldering irons. And usually they start many sentences with “In my times…” or “When I was young…”.
Also analog meters have quite a bit of mechanical inertia which make them slow to react to rapid changes, while decent DMMs have fast-acting bargraphs and MIN/MAX measurements. For faster signals I have a DSO that can freeze them on the screen and perform all kinds of measurements.
Both types have their pros & cons. You need both I think.
“Why then western civilization uses DMMs almost exclusively?”
Mostly because most DMMs are inexpensive, and decent analog VOMs are rare.
On the subject of high impedance, my DMMs intended for electrical work like AC or car/boat electrical have a “low impedance” mode to get around false readings from leakage paths.
I use analog meters for monitoring current for example — always on without batteries wearing down nor need for external energy source. No DMM can do that.
True. Very valid use case. Also battery voltage, where they put some resistance load on it, which gives better idea about battery status.
I’d use analog ohmmeters (circa 1978+) to tell whether an electrolytic cap was taking a charge too fast, too slowly, or not at all.
Today, of course, that’s just a setting. But back then, it was very useful.
Rebuilt an ancient (~40-years old), yet very good, Kamoden 360TRCX recently. Numerous faults, but with the help of a hard to find manual in German, 100% repairable! Very handy to have both analogue and digital meters.
Had a 260 which I salvaged in pieces from a trash can while I was working for RCA in the late ’60s. Some epoxy and replacements for the worn-out banana jacks made it good as new. Checked the calibration against a modern digital meter and it was dead on (all the range resistors were hand-wound wirewounds). The date code in the meter movement was 1951 (RCA had been around for quite a while). Used it for years until I lost it to one of the California wild fires in 2017.
Yes still got one must get out and use it brings back memories I am 64 years old now been doing electronic since 8 years old
Is there a modern analog multimeter with a meter close to the size of the one on the Simpson, but with a high input impedance?
MF-47 at Aliexpress has 20 kiloOhms/Volt. Low price.
I was raised on the Simpson 260. My dad was a TV repairman back in the 1950’s & 60’s. Back then this was better than a Fluke 23 or 77. When he passed I inherited all of his old equipment. Back in 2010 when Nashville flooded so bad, during the cleanup I discovered that unbeknownst to me a family member had put a box on the floor to make room for some of their stuff on the shelves. That box had several older radios and test equipment in it, including the 260. During the clean up I nearly cried when I discovered this and pulled that old 260 out of the box and the muddy water just poured out of it and I had no choice but to drop it in the dumpster with the rest of the destroyed items in the garage. I still have not found a DMM that I like, or the works the way I think it should, and I have several. ( P.S. the junk Christmas ornaments that were put on the shelf in it’s place survived unscathed)
I worked at Simpson electric in Elgin Ill in the late 80s. My job was repairing all types of Simpson meters.
It was amazing what people would put those meter through Simpson was one tough meter.
One of the most fun jobs I ever had as beginning ET.
I still find my Simpson meter is the best way to check faders & pots for noise & non-linearities. It is much easier to see little “blips” on an analog meter than a digital one with a clocked refresh.
An analog meter is also much easier to glance at without having to read digits.
…just my 2 cents
I have a analog Micronta from way back, one with FETs. Love it but, its main problem was its sensitivity of static electricity.. Rub by accident the plastic case of the dial and the needle will swing all over the place…
even in the OFF position!!
A damp cloth will destatic most any analog movement
Get rid of that Duraleak battery, get one that won’t ruin your meter..
ABSOLUTELY ! Never, ever use Duracell. They leak badly. Several years ago I bought a multi-pak. TWO of the batteries (AA) had reverse polarity ! I called Duracell and they basically told me I must have installed them incorrectly and that caused the reversal.
In the old analog Navy the goto meter was the AN/PSM-4. I worked in an FECL and calibrated “bushels” of them, and rarely found broken ones. Only problem was periodic tech measuring the resistance of the 300V dc plate supply. (:-) Had some Simpson 360s also… Great meters.
What I love about analogue meters is the visualization of movement.
If a source is changing, it can be seen more easily on an analogue meter. You have a range of minima and maxim.
Makes me wonder why modern digital pocket meters don’t have a simulation of an analogue instrument.
Back in the 90s, I had a “hi-tec” PC interface with a Windows 3.x software.
It attached to parallel port and was very sophisticated for its day.
The program group was full of Visual Basic programs which used plot diagrams and gauges.
Now it’s 2024 and the average DVM still has a cheap one-liner display, monochrome, without backlight.
Like a quarz controlled Casio wristwatch of the 1980s.
And that’s considered advanced. *sigh* 🙄
No thanks, I wonder who’s living in the past.
A good analogue meter still has its place, a digital multimeter alone isn’t enough.
Ideally, a modern multimeter of today should have and OLED display and the ability to visually represent the measurement as numbers, X/Y graph and simulated a moving coil gauge.
With the ability add a delay, just like the real thing.
Many DMMs do have an analog bargraph which updates much faster than the digital display for exactly this reason.
Me too! They are all right! I have three AVOs, two of which need attention. I also a have a couple of cheap analogue meters (Sanwa, Japan). My Flukes are brilliant, they are shock and dirt-proof, and do the job most of the time, but the analogue meters still get used, because sometimes they are necessary. Varying voltages etc. Apart from the love of old klonky stuff, I believe there is a need for analogue. I teach electronics and one thing I like, when doing op-amps, is the centre-zero facility, where you can see a voltage varying above and below zero. Let’s knock either. They have their place. I hope any engineer will recognise that having at least one of each is worthwhile, and will learn to understand where and when to use the appropriate meter.
Don’t forget Eico. I bought one when I was in college (60 years ago) and it still works great. Just needs a battery.
My video summarizes the differences in the various 260 Series. https://youtu.be/eXQLq4X47hk?si=r5frjNVGjRGZVGKW