Metrawatt M248B Post Summary (finding a blown fuse detection circuit) - Page 1
Forum section: electronics / general

author: Cliff Matthews
author_rank: Unknown
timestamp: May 13, 2017, 12:24:37 am
content: My take so far: No bar-graph and just because it's from Nürnberg doesn't mean we should bow down, kiss the dirt and hand over our wallets (err sorry, maybe purses too..)(if you're my age, you'll need to buy new eye-glasses too)Priced for the ISShttps://www.amazon.com/gp/product/B01283LU8M/ref=s9_acsd_hps_bw_c_x_5_w

author: joeqsmith
author_rank: Super Contributor
timestamp: May 13, 2017, 12:55:48 am
content: Hold on there... We are just getting started with this review. There is plenty more to come!

author: Cliff Matthews
author_rank: Unknown
timestamp: May 16, 2017, 08:14:29 pm
content: And the beat goes on...Screwdrivers still waiting to see action. You must have a ton of patience for H.O. to even cough a little (für das Produkt). Funny to see those DMM's moving along without any sub-titles or voice-over, but in the end I figured out what I was watching. It was nice to see an RF chamber.

author: Cliff Matthews
author_rank: Unknown
timestamp: May 19, 2017, 03:46:15 pm
content: Part 3- We see it sucks more juice than a Cadillac (and it's comparatively priced).

author: Cliff Matthews
author_rank: Unknown
timestamp: May 21, 2017, 08:31:15 pm
content: Gossen still not responding.. great service? It'd be better if they told him to hang-on while they talk to the dumb-cuff's in engineering.

author: Cliff Matthews
author_rank: Unknown
timestamp: May 22, 2017, 06:34:40 pm
content: Testing with arb-gen waveforms...

author: Cliff Matthews
author_rank: Unknown
timestamp: May 24, 2017, 11:03:49 am
content: Round 5 on the killer Metrahit. Now latching relays can trip into states where high AC voltages measure as safe, giving operator a false reading of safety. Admittedly, a tape eraser emits a very strong field, but one wonders if this could be a killer meter after a side impact with enough G's to trip it the same way?Edit: Those mixed-up terminals remind me of older idiot-style Volkswagen side mirror controls... while industry had accepted a joystick-style standard since the 70's, these guys used a dumb slide/rotary switch perpendicular mounted on the door (if you've used one, you'd remember it).Another posted with a simple magnet..An even smaller magnet (with proximity shown) what a piece of junk!

author: Cliff Matthews
author_rank: Unknown
timestamp: May 28, 2017, 10:00:32 pm
content: Take it apart!!1st part of what many have waited for. The big transients are still to come..

author: Cliff Matthews
author_rank: Unknown
timestamp: June 05, 2017, 02:32:43 am
content: Gossen's Metra finally takes some hits.Something in that HIT name, with all those MOV's and GDT's, it better not have failed!I love this guys channel. I'm not sure who has more fun, him or us? Here, Fungus want's to throw it. OK..

author: Cliff Matthews
author_rank: Unknown
timestamp: June 07, 2017, 12:54:13 am
content: Joe, as I understand after hitting 100 users, you can update your channel with a custom URL.If it's Ok with Dave, I'd like to suggest the channel photo: The old transient gen along-side the EEVblog DMM

author: joeqsmith
author_rank: Super Contributor
timestamp: June 07, 2017, 03:59:16 am
content: If you actually watched part 7, I ran that EEVBLOG meter again on the transient generator.I could pull a real URL and point to the YT channel or run one of the free domain servers but consider that the vast majority of the traffic comes from search engines. YT is by far the largest. EEVBLOG, even though this is pretty much the only place I post about the testing accounts for maybe 7% of the traffic. Once the 121GW is released we will have a look at it. My guess is that meter has a larger fan base than any meter I have looked at and you can't even buy it!Growing the channel it is not something I have been concerned with.Many very generous people have asked about donating but really I don't see that happening any time soon. I hate to say how much time I have wasted on this GMC meter. Three different distributors have asked about supplying me with products which I find very strange. I can only assume they don't actually watch the videos or they would know better. If a company sent me a meter to review, they would have to be VERY confident in their product. You saw how bad it went for that GMC meter.

author: Cliff Matthews
author_rank: Unknown
timestamp: June 07, 2017, 11:51:43 am
content: Yes, I watched part 7, but since someone else seemed intent on getting a good look at that cute decal..Just thought a still shot of the two (like bad meets good) would frame-up the channel nicely.Those distributors could be willing to gamble on getting good results, so they can link to the test and clear out overhead on dead stock (like theGarageMechanic'sCompanion you bought). Reminds me of 35-years ago I was a manager at Radio Shack, and they gave sales guys an incentive called SPIFF's to clear out lazy-dog inventory.

author: Cliff Matthews
author_rank: Unknown
timestamp: June 09, 2017, 11:00:56 am
content: So this is (I take it), the last focus on the Metrahit 248b for a while. Will you run tests with the new shield?That's good news on the 121GW!! I've had my wallet itching me on that one for a while.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 09, 2017, 05:11:37 pm
content: Another follower asked about running the tests with the shield as well. I did try the BT interface and that seems to work just fine from an easy 20' away but I am guessing you are concerned with the HV. Keep in mind that the shield is downstream from the primary clamp. What I will do is repeat the last test I ran and maybe use the ESD gun. No need to ramp things up.

author: joeqsmith
author_rank: Super Contributor
timestamp: June 10, 2017, 12:57:44 pm
content: Covers a few other questions people had about the meter, including if the meter will still survive the transient tests.

author: Cliff Matthews
author_rank: Unknown
timestamp: June 12, 2017, 10:36:37 am
content: And another "final reassembly" to clean up contacts etc. (some ohms readings were a bit low).I thought poor contacts typically equal higher resistance..

author: The Soulman
author_rank: Super Contributor
timestamp: June 12, 2017, 12:05:17 pm
content: Quote from: Cliff Matthews on June 12, 2017, 10:36:37 amIts not contact resistance that was the issue here, but a parallel resistance due to contamination on the pcb (fingerprints, spit, etc.).A parallel resistance of 3,7941 G Ohm would have caused the difference between reading 9,9761 and 10,0024 M OhmBTW. the "official" thread is here:https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/1305/

author: joeqsmith
author_rank: Super Contributor
timestamp: June 12, 2017, 04:25:45 pm
content: Quote from: The Soulman on June 12, 2017, 12:05:17 pmSoulman is correct. It does not take much to screw things up.