Radio Society of Greater Bixby

Mark KJ5JVV brought his five hundred dollar Fluke model 177 meter and verified our previous readings on a 100 Ah LifePo made with our seven dollar Harbor Freight digital meters, having found our place between the arches in the center of town and the Bixby Police antenna (see pic above) and then went across the street to Scott’s hamburgers on the North side of Dawes St, verifying that the LifePo was down to 13.15 Volts as a result of being hooked up to a Yaesu 991 for a day and a half trying to see how long the 100Ah would last (13.15 suggests it’s down to under 30%).

Note: Sentence above will not be entered in the Bulwer – Lytton contest for run on introductory sentences. It’s just practice.

Excluding a 57 yr old analog and a faded red Harbor Freight digital with visibly changing readings, all the meters we had (a Fluke and several Hbr/Frts) had voltage readings spanning just a 0.7 % range with the Fluke reading centered in that range (so we can expect a reading of 14.4 on a fully charged LifePo to be accurate). The 11 mA current measurements ranged 3% with Mark JVV’s Fluke 177 way off, nearly 30% low at 9.21 mA. We surmised the cause was a previous owner greatly exceeding the 400 mA stated max range which damaged the internal shunt (and likely the reason Mark got the great bargain. Hey Mark, when measuring mA with that meter, figure it’s 30% low).

The other measurements, a fifty year old 1k resistor with a gold band (that’d aged up to 1090) and the 122 Volt AC line voltage, all came out within a percent – great considering Harbor Freight says they’re only accurate to 1 pt 2 percent. The Hbr/Frts jumped around on the 120 AC while the Fluke seemed to show an ‘average’ reading that didn’t jump around so much.

ADDENDUM: Kenny KJ5EKW offered his Fluke 117 (which he uses professionally measuring black, white, and green wires) and it verified the 11mA current reading that our used $500 Fluke model 177 had erroneously suggested was 9.21 mA.