[Boatanchors] Voltage Calibrator

[Phil]

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
>