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Title: O.B. McCLINTOCK 3-Scale Milliamp Meter Shunting Post by: W9ZSL on July 12, 2014, 06:44:15 PM So I bought this meter awhile back and now I'm wondering what to do with it. It is identical in appearance to a Simpson model 27 including the art-decco housing. The scale says "Made by O.B. McClintock Co Minneapolis, Minn, U.S.A."
The scale is 15, 150 and 300 MA. I measured the resistance at 6.7 Ohms. I assume that "as is" it is good for 15 MA and I'll have to provide shunts for 150 and 300 MA? I'm thinking of using it with a single 813 to measure plate, screen and grid currents. I'll be running close to 1500 VDC on the plate and bias/screen voltages accordingly. Any thoughts? Title: Re: O.B. McCLINTOCK 3-Scale Milliamp Meter Shunting Post by: Opcom on July 12, 2014, 07:55:42 PM Meters like that sometimes have no relation between the scales and the full scale current. Best to test starting low.
Title: Re: O.B. McCLINTOCK 3-Scale Milliamp Meter Shunting Post by: W9ZSL on July 12, 2014, 10:11:02 PM That's what I thought too. I have a 15 MA meter and shunted it to double the current to 30 because I needed to see 27 MA on an oscillator/buffer. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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