• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Klein CL390 AC/DC 400A Auto-Ranging Clamp Meter

Wire Weasel

Senior Moment
Dec 13, 2008
Reviewing this here as we radio folk may wish to have the ability to read DC Amps being pulled by rigs and things like 12V amplifiers. Direct Reading DC Clamp Meters aren't new but are a more modern type with these stand-alone units being AC only in the past. I saw this one being used by a radio tech in a Youtube and thought I would check into it. I liked the specs and what came with it and everything it did so I decided to pick one up. I've used AC clamp meters for years in my working background. I had a Fluke for many years but it died after long service. About a year ago I got an old school Amprobe to replace the Fluke. There's tons of them on the used market and I got a nice one with carrying case for $15 bucks on ebay. The original style Amprobes are great for they work off of magnetic detection only so the unit does not use batteries.
On to this Klein. I'm very impressed with it. The pic looks like the display numerals are blue but they are white on black background.
AC/DC volts & Amps to 400
Resistance to 40Megs
Capacitance to 4.0mf
Diode Check
Temp with included K Thermocouple / -40 to 1832F
Also reads AC Frequency
Checked all functions on various devices and compared readings against a Fluke DMM, Amprobe for AC current and a high quality glass mercury thermometer. Measured on several resistors & capacitors with known values. All readings on all functions were nearly exact to other known good instruments. Checked DC amps on my RM Italy KL 703. At 100 Watts dead key I expected to see a bit more than 20.0 amps considering the two fans. Fans were drawing a bit more than .1 amp each and with the key down the meter read 20.4 amps so I'd say it's right on.
Meter is easy to find on eBay or Amazon and other places and I saw for as little as $55 so I'm saying this meter is a keeper.


  • Screenshot 2023-04-15 at 4.08.47 PM.png
    Screenshot 2023-04-15 at 4.08.47 PM.png
    1.9 MB · Views: 92
  • Screenshot 2023-04-15 at 4.07.55 PM.png
    Screenshot 2023-04-15 at 4.07.55 PM.png
    1.6 MB · Views: 70

Help Users
  • No one is chatting at the moment.
  • @ Jim5570091:
    Maybe. I wasn’t impressed with just clamping the shield wire to the boom with a hose clamp. I built a l bracket with so239 female hubs. I posted a picture on the recent gallery’s.
  • @ Jim5570091:
    Well I cut the matching stubs down 1 inch at a time from about 20” down to 6”. Still no real changes.
  • @ 555 Central Missouri:
    Hello everyone, I have a old courier centurion pll 40 channel SSB, it has the extra channels and it has another switch that just moves the frequency down one channel on the dial, what is the purpose for this?
  • @ BJ radionut:
    LIVE 10:00 AM EDST