[Boatanchors] Voltage Calibrator

[J. Forster]

Good idea.

You can buy a new 3 1/2 digit DMM for <$20. That should be good to better
than 1%, certainly good enough for a VTVM cal, DC, AC, and Ohms.

And, you might find you like the DMM better than the VTVM, except for
tuning to peaks or dips.

Best,

-John

===========




> How about a variable power supply, then put a DVM (digital Voltmeter)
> whose accuracy you trust, in parallel with your VTVM across the power
> supply.  Even a cheaper idea, depending on how high you want the
> Voltage, if you're talking Voltages in the hundreds, snag the B+ from a
> receiver, put a high value pot across it, then your parallel VTVM/DVM
> across that.  MOST VTVM calibrations that I remember only had one
> adjustment that affected all ranges, depending on the 1% resistors in
> the divider to set the rest.  From what I remember, typically they
> (Heathkit etc) used a NEW 1.5VDC D cell for calibration purposes and had
> a mark on the meter for the "calibration point". Now with DVMs we have
> much more affordable 'accurate' ways, and the usual DVM can be read much
> closer than the analog dial of a meter.  So, it makes sense to use the
> DVM as a "standard".
>
> Hope this helps you.
>
> 73 de Phil,  KO6BB
> http://ko6bb1.multiply.com/ (OTR Blog)
> http://www.qsl.net/ko6bb/  (Web Page)
>
> RADIOS:
> Grundigs: Satellit 750 (2011), S-350 (2006)&   G6 (2011).
> Kenwood: TS130S Transceiver (circa 1980).
> Radio Shack: DX-380 digital portable (circa 1990).
> Yaesu: Two FT-8800 Mobiles, VX8R Quad-Band (circa 2010).
> Zenith: Royal-7000 Transoceanic (circa 1969).
>
> ACCESSORIES: MFJ 1040C Pre-Selector, W9GR Audio DSP.
> ANTENNA: 88' Long Ladder-line fed dipole, Apex at 35 feet.
>
> Central California
>
>
> On 12/29/2011 4:27 PM, David C. Hallam wrote:
>> What is a good DC voltage source that doesn't cost big bucks to use to
>> calibrate a VTVM?  I can't afford several hundred dollars for a piece of
>> test equipment with such limited use as a voltage calibration source.
>>
>> David
>> KW4DH
>>
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