*Help!* Crazy Tailcap Readings...Excel XL830L

New battery was the first thing I did if you read the OP.

My old Elenco meter is giving voltage readings about 0.10v too high (at least at around 4 to 6 volts) and gives too high of current readings. Thread I posted about current here. I never fixed it. I just replaced it (although I find myself using it and forgetting the voltage readings are a little high). There are quite a few pots inside mine.

My XL-830L has proven good though with thick leads (I posted my test in the original T-Mart deal thread dchomak linked).

I'd suggest always trying to test your meter / leads with a Nanjg driver and fresh battery since you know what you should be reading.

-Garry

Garry, what do you get when checking your Nanjg for current?

So, the way you calibrate these babies is…“throw it out and get a good meter?” I like it. :wink:

Post #65 in that thread. I was getting 2.05A on a 2.1A Nanjg (6x7135's) which matched my 2.051 on my "good meter", both with short thick 12ga leads.

-Garry

Ah, thanks. I think my meter might be a return…it had a battery already in it (plus another wrapped battery) and there was a crack in the protective cover. This was also the second one they sent out, first one didn’t make it here.

Great deal….“Two 9v batteries for $5.94!!”….comes with piece o’ plastic cr@p meter. :frowning:

I'd recommend taking a step up in meter quality, especially if this will be your only meter.

-Garry

I think that is good advice!

Really, my old pocket-sized Radio Shack meter has been rock-solid for over 20 years, but it doesn’t do current.

I’m going to poke around in the Excel and see about calibrating it with a known source…

Some very quick recommendations on another meter:

Equus 3320 (thinking it might even be at some Walmarts): $18.74 at Amazon.

Here's a Mastech MS8268 which seems identical to my "good one" but without the lux meter (not sure how good it is anyway) and without temp/humidty (who needs that anyway): $24 at Amazon. My Mastech has a bit of a cheap feel to it (and the probe sockets don't lock the probes in so tight), but it functions well (get what you pay for I guess).

-Garry

Thanks for the recommends!

After messing with the calibration pot inside this meter, I’m convinced this one is rubbish. I couldn’t even get it close to what it should read on a 2.8A Nanjg.

At least I got some good leads made for when a proper meter comes along!

I ordered the Mastech from Amazon as well as some helping hands.

“Back in the day” a VTVM was a rare item, not just anyone had one - but I did. Mid 60’s, this one cost $39.95 and it was a KIT. You had to put it together, all point to point wiring!

And note there is no Amp scale.
This next one also came in kit form and cost $69.95, a for real DMM - from the mid 70’s
Sabtronics Model 2000

Back in the 60’s, $39.95 was a LOT of money! It is because of that, I am happy to use a cheap Harbor Freight meter and not complain. Relatively speaking, a bargain, and more accurate than either of these 2. That is also why I can’t help buying meters, they all seem so inexpensive.

EDIT: I plan on restoring these 2 and get them up and running.
Speaking of calibration, in the directions for the EICO VTVM, the calibration procedure was to plug the probes into a US AC outlet and adjust for 117V. The DC calibration was connect to a fresh Carbon-Zinc D cell and adjust to 1.65V!
And that was it!
The ohms adjust was just under the meter face, you can see it in the pic, and had to be constantly adjusted as the Vacuum Tubes heated up.
God I feel old!

I used to have an old US Army analog meter. My dad brought me home a couple years ago as a teenager and I kept the best one (well last I knew I left it at my parents house). No idea how old it was. It was in a big heavy case where the front unlatched and came off. Very large case with just a small analog meter in the center. Here is an ebay listing for one that looks like I remember. I'll have to see if my parents still have it and if I can get it (just to keep it).

Pics from that Ebay listing:

Glad I'm not using that thing anymore!!

I have a Mastech MS8229. Reads very comparable to my 87V. Seems to be a very good low cost meter.
The only thing I could complain about is it will not work outside in the sun. The screen will completely black out, if left in the sun more than a few minutes. Temperatures outside where in the 70’s incase your wondering. Once it cools back down the screen will start to come back. The 87V had no problem dealing with the outside sun, had to go fetch it once the Mastech blacked out. I would not recommend the MS8229 to anyone who intends to use it outside. :frowning:
I do think the Mastech is definitely a step up from what you had.

My "Mastech" is the Harbor Freight "Centech" branded one found here. Seems to be a Mastech MS8229. I'm not sure if I've ever used it outside to be honest. (Also not sure if I've ever used a DMM outside at all.) So I've not experienced any screen issues, but it could just be that I've not used it outside.

-Garry

Garry, another thing some do not realize, is that an old, analog mechanical meter like yours had such a low internal impedance that they could “load” a circuit and thereby not give accurate readings. That’s why a VTVM (vacuum tube volt meter” was an “elite” piece of test equipment. Another reason I appreciate so much the newer meters. Even the cheap, cheap ones.

One more thing, any meter, no matter the cost is only as good as it’s calibration.

I would not have thought, I would have ever used mine outside either. My air conditioner quit this spring, so I went out to check the capacitance of the run capacitor in the outside unit. That’s when she blacked out while I was removing a panel to gain access. No more than a few minutes had went by. Had to go get the fluke. Sure enough the capacitor was bad. Saved myself a expensive visit from a AC man I’am sure. Run capacitor cost me 15 bucks and has been working fine ever since. :bigsmile:

Now that's something that would NEVER happen around here! :) (i.e. running an air conditioner in the spring). We only have two seasons here, winter and winter is coming.

-Garry

If you lived where I do and had a significant other. You would have a air condition or no significant other. :bigsmile:

Thanks Garry! The MS8268 came in from Amazon and it seems to be accurate…even with stock leads. ~2.77A for a Nanjg 2.8A driver…now we’re cookin’!!

Good! Glad it was a good one. How are those jacks? Mine are a little loose.

-Garry