Cen-Tech P37772 DMM... - Page 1
Forum section: electronics / testgear

author: knockbill
author_rank: Regular Contributor
timestamp: October 26, 2016, 11:30:34 pm
content: This is the last of the four DMMs I picked up a couple weeks ago,,, Its a Cen-Tech, but seems to be much better than the usual HF freebys,,, This one has a lot more ranges in each mode... Modemhead pointed out how sort out the really cheap DMMs, so I thought I'd add this one to the mix... Its got a few scratches on the display, but is very accurate in all the ranges I've tried so far,,, Doesn't have the Temp probe, but its not a big deal... It has a frequency mode I'm not sure how to use, but there is probably a manual available online...All in all, when I sort the Fluke out, I should be good on DMMs for a while!!!

author: ModemHead
author_rank: Frequent Contributor
timestamp: October 27, 2016, 01:38:19 am
content: Cen-tech P37772 ManualLooks like a rebranded Mastech M9508. 90s vintage. It probably also has a 7106 clone chip, but has better support circuitry with better AC functionality than the real cheapies. From what I read about these, you can probably expect problems with the flip-up display, eventually.I like your Wavetek better.

author: knockbill
author_rank: Regular Contributor
timestamp: October 27, 2016, 11:24:56 am
content: Well, got it with the Wavetek actually, buck a piece... I'm pretty sure HF sells this one also,,, I like using this one better than the Wavetek, as its simpler and has less stuff flashing on the screen, and the big display is handyl!!I'll have to Google "flip up display" and learn about the problems... Found a manual online last night and didn't realize it had a Cap value tester on it,,, doesn't bring them up to working voltage, but seems very accurate measuring value...Its a MUCH better deal than the GB!!!!

author: rsjsouza
author_rank: Super Contributor
timestamp: October 27, 2016, 08:15:12 pm
content: knockbill, you may be interested in looking at joqsmith's test of this meter at:

author: knockbill
author_rank: Regular Contributor
timestamp: October 27, 2016, 09:42:42 pm
content: Yep its pretty accurate,, suits my use well,,, looks like it popped where he "fixed" the jacks... they usually give up when they're pushed to the limit... I had a HF freeby connected to an RCA theater amp, with apparently bad caps,,, the DMM popped and jumped of the bench in a ball of flames,, It hit 1100V...I use my Triplett 850 for over 500VDC,,, Its good to 1500V...

author: joeqsmith
author_rank: Super Contributor
timestamp: October 30, 2016, 04:11:16 pm
content: I bought a few of these meters and gave them away. One went to a friend who uses it in a garage. I saw it a year or so after and it was pretty well trashed. I used one for my own car/bike troubleshooting for several years. The solder joints for the banana connectors cracked at one point, which I "fixed". I used the meter up until the display started to fail.The second one I had ended up with the same problem. I repaired it and gave it away but I think the person who has it now is seeing the same problem.That ribbon cable setup is not the best.Quote from: knockbill on October 27, 2016, 09:42:42 pmIt's not uncommon for me to run more tests on these meters before they are recycled and I don't always make videos of the results. In the case of this meter, I actually had changed the meter to see if I could improve it.ag0: Shows where I had reflowed the two connectors and added some solder. This picture was taken after the video was made. Note there are no signs of a breakdown near the rework.ag1/2: Showing some of the damaged area. Note that the creepage from the input to the common was not near enough.This was the cause of the breakdown. You can see where I had removed the copper and cut the shunt. After this the meter did not breakdown however even with this area changed, I doubt it would have faired very well in the tests.It's a crap meter but that's not to say it didn't serve me well. I replaced it with another low end Mastech from HF that I still use today.