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THE AM BULLETIN BOARD => Technical Forum => Topic started by: Opcom on November 12, 2010, 11:41:10 PM



Title: Weston 633 clamp on ammeter - how many variants?
Post by: Opcom on November 12, 2010, 11:41:10 PM
Recently this showed up. It is the most dignified and manly clamp-on ammeter I've ever seen. This meter is 14" in length and can acommodate about a 2" cable. It's heavy.
This one is the 633-60, type VA-1, Weston, and also has AC voltage as the 6th switch position and note the inputs via ports in the side up to 600V. Apparently, the engineer is to connect some rather scary clip leads to them, and thereto the AC mains. It was given to me because there was a crack on the case but some black epoxy fixed that. It had not ruined anything. I can see this hanging on a 000 conductor with a couple of clip-lead clamps, one to ground and one from that 600VAC port to the conductor.

633-60 type VA-1 (the one shown, and as above) Amps 10-25-100-250-1000 and volts position with 3 ports to 600VAC "made in USA" inscribed on meter face.

633 type SVA-1, which is a Daystrom Incorporated Weston product otherwise apparently like the VA-1. Not inscribed 'made in the USA' on meter face. No "-60" suffix

633-85 type A-3, - does not have a voltage scale, has six AC amps scales apparently top is 2000A. Meter face inscribed WN/A&M on lower left. These seem to have a slightly different movement. Newer-looking, Not inscribed 'made in the USA' on meter face.

633-60 type A-2, made in USA on the meter face, with the "Weston" writing in a different spot on the meter face (lower left instead of along the top of the face) and does not have a voltage scale. It has 10-25-100-250-500-1000 ranges. - so instead of AC volts, it has inserted a 500A scale. "made in USA" inscribed on meter face.

That's 4 types. I wonder how many variations of the venerable 633 there are?

Are some foreign-made? None I saw pictures of, that did not say "made in USA" indicated another country of origin.

Various internet prices from $35 to $100 seem common on them. Some up to $300. They must have cost a lot new.


Title: Re: Weston 633 clamp on ammeter - how many variants?
Post by: W7TFO on November 13, 2010, 01:01:42 AM
Hi Pat,

I have several of these in my tool kits.  Some have the voltmeter option.  One is good to 500A, the others to 1KA.

I offed all my Amprobe units after my first one of these.  There is no finer AC ammeter.

Uncle Sam bought a lot of these in generator test kits.  So did virtually every utility company in America.

73DG
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands