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Title: Clamp on AC ampmeters? Post by: N8ETQ on October 23, 2012, 10:58:39 PM Yo'
Clamp on AC ampmeters? Anyone know if these things read pretty high if there near the Iron. Mine is reading 31A next to the steel cased xfmr with the bleed I at about 200 ma. and a 3X1 making 800 W at 4Kv. Ip is reading around .4A. Do I need to move this thing further down the line? 110 Primary. I can "clamp" on one of the primary feed lines but right next to the xfmr but the math dose'nt work out. go figure.... I finger the thing is around 17:1. Maybe it's bad. TIA. /Dan Title: Re: Clamp on AC ampmeters? Post by: W7TFO on October 23, 2012, 11:02:27 PM If it is in the magnetic field of the transformer, it will read off. Flip it over and see if it reads really low.
Measuring somewhere else in the unit might be best. 73DG Title: Re: Clamp on AC ampmeters? Post by: N8ETQ on October 23, 2012, 11:23:30 PM Hey D
Interesting concept. I suspect Not, but will have to try it now that it has come up. One would think they would make one side of the "Clamp" thing RED. I'll have to get back to you on that. And you known I will! /Dan Flip it over and see if it reads really low. Measuring somewhere else in the unit might be best. 73DG Title: Re: Clamp on AC ampmeters? Post by: N8ETQ on October 25, 2012, 09:14:17 PM Yo'
I think it was RF. Moved it down the line and getting around 10A either way.(up right or the other way that you cant see the display) It now indicates around 12 A with a 600 watt cw signal into my poor "Cantenna". Surprised They never put a "Dipstick" on those things! It's a Cheapie Farbor Haiegt Job. Comes in handy none the less. As long as your aware of It's "Vulnrabilites". My Wife says the same of me! /Dan Title: Re: Clamp on AC ampmeters? Post by: Opcom on October 26, 2012, 12:25:29 AM It's hard to mess up making a clamp-on AC ammeter, the old kind anyway. Now that you have seen why it misbehaves, at least you will be sure how to get the accurate readings from it going forward.
Title: Re: Clamp on AC ampmeters? Post by: W1RKW on October 26, 2012, 05:50:18 PM I bought a clamp on type a few weeks ago and tested against 2 DMMs that were in circuit. The clamp-on read about an amp higher than both DMMs. Also compared it to another clamp on. The other clamp-on read higher by the same amount also.
Title: Re: Clamp on AC ampmeters? Post by: kb3ouk on October 26, 2012, 08:50:44 PM You know, it would be neat if somebody made a clamp on meter that measured RF current in coax. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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