[Boatanchors] Meter for ARC antenna relay... Clarification

[J. Forster]

I phrased this badly:

The meter is a low resistance voltmeter, approximately 20 mV FS. The
voltmeter resistance is such that it draws 750 mA at 20 mV.

.............

I should have said "With 750 mA of RF going through the TC, the voltmeter
will see 20 mV. Offhand, I don't know the FS voltage for the meter.

Google Images has a schemat of the BC-442. I'm pretty sure the meter
markings are just a logging scale, not actual Amps RF.

-John

================


Several things:

In the ARC-5 or BC-442 there is an RF current transformer between the
antenna circuit and the thermocouple. It may or may not be 1:1

No RF is applied to the meter. The meter current "19.5 +/- 1.5 mv, 750 ma"
is produced by heating of the thermocouple. It is DC.

The meter is a low resistance voltmeter, approximately 20 mV FS. The
voltmeter resistance is such that it draws 750 mA at 20 mV.

-John

==================




> Does anyone happen to know what meters go with the thermocouples used
with the command sets?  Fair has the thermocouples but not the meters
and they'd
> probably work for some of my lower power projects.  According to the
data plate, they're rated at "19.5 +/- 1.5 mv, 750 ma" but is that RF,
whatever to the meter or something else?  For full output on CW (40w
into a roughly 16 ohm capacitive load for the AN/ARC-5 transmitters),
the RF current should
> be around 2 amps with a little rounding and some wiggle room which makes
things slightly confusing.
>
>
>
> Any thoughts or advice?
>
>
>
> Best regards,
>
>
>
> Michael, WH7HG, A&P 1803851 Ph: 1-866-733-0218
>
> I live with a maniac at home... my other me.
>
>  <http://www.nationalmssociety.org/chapters/NTH/index.aspx>
> http://www.nationalmssociety.org/chapters/NTH/index.aspx
>
>  <http://wh7hg.blogspot.com/> http://wh7hg.blogspot.com/
>
>  <http://kludges-other-blog.blogspot.com/>
> http://kludges-other-blog.blogspot.com
>
> Hiki Nô!
>
>
>
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