[time-nuts] GPS Antenna Voltage-Dropping

Brucekareen at aol.com Brucekareen at aol.com
Thu Sep 3 01:04:28 UTC 2009

I bought a 3.6-V Trimble Bullet GPS antenna on ePay and wish to use it with 
 my T-bolt.  Rather than try to internally modify the T-bolt to provide a  
3.6-V antenna feed, I decided to try to build an in-line dropping adapter.   
I seriesed two Si diodes inside a 100 pf tubular ceramic capacitor and 
installed  the shrink-wrapped assembly inside a salvaged BNC-M to BNC-F coaxial  
assembly.  Unfortunately the completed assembly exhibits about a 4-to-1  
VSWR when terminated in a 50 ohm load.  Has anyone else tackled this  
The 3.6-V Trimble antenna has less gain than the 5-V version which  makes 
my planned antenna rcable run on the edge even without the high  VSWR..
Bruce Hunter 

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