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RF Ammeter.
Finished project.

This rf ammeter will help in determining whether the in-line current is at maximum going "up the stick" or in-line going to ground. The meter was drawn with F5BU's Galva software, available as a free download from the internet.
 
 
RF Ammeter photo
 
 
Inside look.

Here is an inside view. The current transformer was wound with twenty five turns over the centre conductor of an air celled inner conductor of a piece of 75 ohm coax. Teflon tape is used to provide additional material for aligning the core. The transformer provides the reference voltage for the detection & metering circuit. Spot the simple fault - can you see why this circuit won't work and why?
 
 
Inside the RF ammeter
 
 
The answer.....

The first capacitor is across the diode! This will allow the rf current to bypass the diode !! Doh! The capacitor should be placed after the diode and to the return (blue) common lead.
 
       
    2006 - 2009 S.Spirat 
Another SPIRAT initiative