[ARC5] RF ammeter

[Mike Everette via ARC5]

The ARC-5 meter has an external thermocouple.  The ART-13 meter has an external pickup loop (current transformer), which keeps the high RF voltage out of the meter itself.  And, the ARC-5 meter has a current transformer to feed the thermocouple.

It's been a while since I looked at the TCS schematic to see how those meters are configured; but if I remember right the RF goes directly through them.  Are they mounted directly to a metal panel, or to some kind of insulating material?  I used two in a home brew balanced line antenna tuner back in the 1970s, and mounted them on a piece of plexiglas behind an aluminum panel with over-size holes for the meter case flanges.

73

Mike
WA4DLF

--------------------------------------------
On Thu, 8/7/14, D. Platt <jeepp at comcast.net> wrote:

 Subject: Re: [ARC5] RF ammeter
 To: arc5 at mailman.qth.net
 Date: Thursday, August 7, 2014, 5:01 PM
 
 Gents,
 
 Are not the RF ammeters on TCS
 stuff panel mounted?  How 'bout the 
 ART-13 or the '275N?  Or... am I not
 seeing things correctly?  Of course 
 we're not talking high power with these
 units, either.
 
 Jeep -
 K3HVG
 
 On 8/7/2014 4:22 PM,
 Kenneth G. Gordon wrote:
 > On 7 Aug 2014
 at 12:50, Mike Everette wrote:
 >
 >> I'd be wary of mounting one of
 these meters in a steel panel or box because its
 >> calibration would be adversely
 affected.
 > As a matter of fact, ANY RF
 ammeter is supposed to never be mounted on a
 > steel panel, and I would avoid aluminum
 for the reasons you state: possibly
 >
 arcing.
 >
 > Ken
 W7EKB
 >
 
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