[Top] [All Lists]

Re: [Amps] Measuring fil V

Subject: Re: [Amps] Measuring fil V
From: "jim.thom" <>
Date: Tue, 7 Jun 2022 15:26:59 -0700
List-post: <>
Date: Tue, 7 Jun 2022 23:08:02 +0100
From: Steve <>
Subject: Re: [Amps] Measuring fil V

<Good points, Jim. I stick with resistors as it avoids embarrassment
<if/when the meter wires get shorted. Been there, done that..... :-)

<Steve G8GSQ

##  Points well taken.  I thought of that too. My..'fix' was a small  value
resistor in series with one or both metering legs.   These days, I install
a single fast fuse, in just one meter leg.   The fluke dvm's have fuse
protection built in, but a small, low value fuse  will also work.   Trying
to stuff large amounts of fil current through 22 ga hook up wire to the
metering test jacks results in instant melt down.

## beware though small value, fast fuses, like the  3agc  250-350-500 ma
types, are not zero ohms across the fuse.   They are typ 5-6-7-8 ohms on a
new good fuse. Non issue if using a high Z  dvm.   But it could affect an
iron vane type of panel meter.

##  The 0-15 vac panel meter is installed on the front of the HB amp..with
the pair of  DVM  banana jacks right below it.  The  3agc fuse holder
beside/ below the jacks.

## I said  10kw resistors.   Was supposed to be 10 k ohm resistors.

Later.... Jim   VE7RF
Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>