Re: [Amps] plate voltage meter shunt

["Carl" <km1h@jeremy.mv.com>]

I wouldnt measure HV that way either. As caps age and leakage increases it 
distorts the voltage reading. If carbon comp resistors are used for 
equalizers they drift high.
Configuring  a meter in the string to monitor leakage current would be 
beneficial in the long run with new high quality caps and in the short run 
with used bargains.
For the few extra dollars dedicate an independent string of 1% HV resistors.

Carl
KM1H



























































































































































































































































































































































































































































































----- Original Message ----- 
From: "Jim W7RY" <w7ry@centurytel.net>
To: "Bill Turner" <dezrat1242@yahoo.com>; "Amps" <amps@contesting.com>
Sent: Sunday, November 04, 2012 12:51 AM
Subject: Re: [Amps] plate voltage meter shunt


> As I remember... Henry (I know the Viewstar/B&W works this way) does that 
> in some of their amps. I've had mixed results. As the bleeders heat up and 
> the caps do too, the plate voltage meter drifts. And the voltage is not 
> the same across each cap. The one with the metering circuit has lower 
> voltage across it.
> 73
> Jim W7RY
>
>
> -----Original Message----- 
> From: Bill Turner
> Sent: Saturday, November 03, 2012 7:22 PM
> To: Amps
> Subject: Re: [Amps] plate voltage meter shunt
>
> ORIGINAL MESSAGE:
> On Sat, 3 Nov 2012 14:15:44 -0700 (PDT), W9IIX wrote:
>
> > I am installing a meter to measure plate voltage 1-5000v@ 1a dc,
> > the meter has a 1ma fs rating.  the serial resistance I have
> > made up in the past has been 3 watt metal film resistors in
> > series. since they can only rated for 200v per resistor it takes
> > many to do the job. Can some other resistor type with a
> > higher rating be used in a safe manner for this purpose?
> > ...tnx, Doug,w9iix
> REPLY:
> Does your power supply have a string of electrolytic capacitor with 
> equalizing
> resistors across each one? Install the meter in series with the bottom 
> (negative
> end) resistor and shunt it with a potentiometer or fixed resistor for
> calibration. A few minutes with Ohm's law will give you the values.
>
> Hint: do the calculations based on the full scale reading of the meter, 
> not the
> actual HV reading.
>
> 73, Bill W6WRT
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