Our high school direct conversion project made me realize that I really need to upgrade my digital multimeter. I've been using an old Radio Shack DMM that I bought about 25 years ago. It is OK, but it is not auto-ranging and it is starting to physically deteriorate. So off I went to Bezos-land.
First I spotted the Fluke 101. I was enticed by the brand and the low price. But when it got here I was a bit disappointed. It is really small -- smaller than my cell phone. It is auto-ranging, and it does measure capacitance, but it doesn't measure hFe and the frequency counter only goes up to 100 kHz. I couldn't use it to measure the frequency of our DC receiver PTO. So, back to Bezos. (I'll keep the Fluke as a toolbox DMM.)
Next I found the AstroAI True RMS 6000 DMM. Obviously not as prestigious as the Fluke, but both the Fluke and the AstroAI are manufactured in China. The AstroAI was really inexpensive: Like 34 bucks. And Amazon would do same day delivery here. Soon it was on my front porch.
I've only been playing with it for a day or so, but I really like it. It is auto-ranging, it has automatic shut-down, the frequency counter goes up to 60 MHz, it measures hFe and even has temperature sensor. The frequency counter had no problem measuring the output frequency of our DC RX PTO. The screen is big and bright. And I think the True RMS feature will be very helpful when I try to measure amplifier gain.
I like it. And you can't really go wrong for the price. 34 dollars!
I have the Astro AI DMM in the Amazon ads on the right-hand column of the blog. I should have bought the package with the additional test probes. Click over there on the right for more info.
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Not that long ago we would have thought 34 dollars was very good for just a 60MHz frequency counter! - de G4WIF
ReplyDeleteWhen Heathkit introduced their frequency counter kit in 1971, it was $199.99. It went up to 15MHz, and used TTL for high current draw. You could get a prescaler, that went up to 150MHz, for $179.99.
DeleteAbout that time, they had a DMM kit, I think around $279.99.
The frequency counter was big news, "cheap" at the time. But about 1978, Intersil had their frequency counter IC, and dvm IC. A bit limited, but so many kits moved to both.
Got my first DMM in 1984, about $75 Canadian from Radio Shack.
The True RMS reading is only accurate below 400Hz and at 10 MHz the frequency counter is only accurate to 10KHz. Still, modern DMMs are indeed an extraordinary bargain! Arguably the most important piece of test equipment, too.
ReplyDeleteDon't forget the temperature probe: That will save you lots of time, components, and burned fingers.
de ND6T
There is a Chinese brand of DMMs the has a range of good, sturdy models: ANENG. The AN8008 is good. Amazon and AliExpress.
ReplyDeleteThe Fluke 17B+ I've found on a couple of Chinese outlets (I think AliExpress was one). It's usually about US$85 on one of these sites with 4 or 5 week shipping. Amazon sells them for $130. It's a Fluke. Fluke quality. I think it's made in China for the China market. But a few wind up here (US).