Multimeter for the Boat

[team karst]

Very cool. I recall the PAR units are highly “active” shall we say.
Where the dc clamp ons really shine is around common nodes. Where u have multiple cables at exact same voltage but carrying wildly different currents.

[Spot]

My work's calibration office checked my 10$ generic and 25$ Harbor Freight meter. The HF meter passed the same basic calibration readings as our Flukes at work, the low cost one was deemed 'not good enough'. The HF meter can read a K-type thermocouple which I have found useful.

The same calibration office gave me an old Simpson years ago in all of its Bakelite goodness...

[thomm225]

Originally Posted by team karst

Very cool. I recall the PAR units are highly “active” shall we say.
Where the dc clamp ons really shine is around common nodes. Where u have multiple cables at exact same voltage but carrying wildly different currents.

Th0se were pulse radars with 40 mile range.

3 Phase 400 Hz Power was supplied by large diesel generators on trailers to be pulled by 6 by trucks. We were a Marine deployable ATC Unit/Facility

I do remember our old ASR radar 60 mile range had an 8500 volt power supply for the transmitter which was pulse also with a huge Thyratron Tube. I had a one mega watt (1000KW) peak power rating.

https://www.radarpages.co.uk/mob/tactatc/ups1_1.htm

[wsmurdoch]

It's nice to have an analog meter around when phantom
(capacitance induced) voltages stump a high impedance digital meter or when pulsed DC drives the digital meter's sampling circuit wild (voltage regulator output to the alternator field coil).

[team karst]

Of course, something like a 2 W 100k resistor across the digital VM turns it into phantom elimination meter too. [emoji847]

[kungfoo]

Originally Posted by team karst

Of course, something like a 2 W 100k resistor across the digital VM turns it into phantom elimination meter too. [emoji847]

haha, that works too. The Fluke 117 has a low input impedance mode for both capacitance and voltage for these cases. I'm a big fan of the 117 in general.

[Lake-Effect]

Originally Posted by team karst

Of course, something like a 2 W 100 ohm resistor across the digital VM turns it into phantom elimination meter too. [emoji847]

FTFY

[team karst]

100 kOhm. Good for up to euro home mains. 100 Ohm would quickly fuse or turn into a mini sun. 🤯

Yep, Ohm is capitalized.

[Tellie]

Originally Posted by SailingHarmonie

Some very helpful features on a cruising boat's multimeter:

A clamp on ammeter that works on DC circuits. This is really helpful. Don't leave home without it

A capacitance measuring function. This is vital when you are troubleshooting AC motors.

BINGO! and EXACTLY! A voltmeter on a boat without the DC amp clamp is only half a tool no matter how much it costs.

[thomm225]

Originally Posted by Tellie

BINGO! and EXACTLY! A voltmeter on a boat without the DC amp clamp is only half a tool no matter how much it costs.

Knowing what the amps are definitely makes it easier to troubleshoot an electrical/electronics problem but you don't necessarily need that information as you can usually figure it out with voltage and/or resistance checks.

So your $10 -$15 meter is still king!

Having a Simpson 260 though is just icing on the cake

[team karst]

Absolutely, positively need/want/use dc clamp ammeter for solar and alternator checking/debug.

[thomm225]

Originally Posted by team karst

Absolutely, positively need/want/use dc clamp ammeter for solar and alternator checking/debug.

Sure but you can do it without one.

[team karst]

Difficult to get over 10 Amp scale on the majority of handheld meters. And disconnecting the alternator with a 40+ output running is not a good idea. Maybe u have a compass you hold near the wire ??

[thomm225]

Originally Posted by team karst

Difficult to get over 10 Amp scale on the majority of handheld meters. And disconnecting the alternator with a 40+ output running is not a good idea. Maybe u have a compass you hold near the wire ??

No.

I was trained as an electronics tech in the 70's in the military and have been doing it ever since in various capacities

Training in the military isn't like training at a college where you have a few classes per day.

In the military back then, we received 8 hours/day training as it was our job.

I did it two separate times 1 year each.

On our radar units, we cover the entire schematic pack line for line then watched very boring videos

We learned things like Eli the Ice man.

Eli meaning Voltage (E) leads current (I) in an inductor

Current leads voltage in a capacitor

Then Kirchhoff Law etc

But as a tech, it wasn't about design and the other BS engineers do it was about troubleshooting and that is what I know.

Here are about 3.5 hours of basic electronics if you want to learn

https://www.youtube.com/watch?v=sqxzQkAdJm0

https://www.youtube.com/watch?v=gzb5Bw3Wusc

[thomm225]

Originally Posted by team karst

Difficult to get over 10 Amp scale on the majority of handheld meters. And disconnecting the alternator with a 40+ output running is not a good idea. Maybe u have a compass you hold near the wire ??

Also things like Oscar had a hairy old ass.

Or

Old hippopotamus Alice had zero apples

Sine, Cosine , Tangent.

Sine =O/H

Cosine = A/H

Tangent = O/A