[Milsurplus] RF Ammeter Puzzle

[Bruce MacMillan]

Hi John,

In the art13 manual, T.O. 12R2-2ART13-2 dated 30 March 1956, the rf 
ammeter (M101) is a GE 8DW52AAR84. It is an internal thermocouple type, 
0-0.25 amperes with a 20X expanded scale. Freq range is 0-20 Mc. It is 
coupled to the output of the antenna vacuum relay by xfmr T102 which is 
used as rf meter coupling. No specs on the coil other than iron core, 
single turn primary, single turn secondary.

Bruce   ve7mt

J Forster wrote:

>I have come across a puzzle on RF Ammeters.
>
>The ART-13 uses a TC meter with 5 A FS and the ARC-5 uses a TC meter
>with 10 A FS, yet the ART-13 is a higher power Tx. There is a current
>transformer in the ARC-5's BC-442, but it seems to be a 1:1 ratio.
>
>Is the RF Ammeter in the ART-13 somehow not in the antenna line (but at
>some higher impedance point in the circuit) ? I don't have ART-13 prints
>to hand
>
>Best,
>-John
>