[TenTec] Your semi-annual Astron tip...

[Stuart Rohre]

The problem you could have with the ground looping of the Astron negative to 
its cabinet, and thus to AC ground, is that in case of a lightning surge, 
you have another path to earth which could attract a side streamer of the 
main hit.

This is exactly what happened at our club station.  Our "Mr. Ground It" had 
copper straps on all the chassis and negatives.  The lightning came in a 
coax shield, went to an Astron chassis, and back out the negative lead and 
fried a 2m radio connected to the Astron.  The PC board ground trace was 
vaporized.  However, the radio still worked as long as you had a coax 
connected to its antenna jack, to provide a negative path for the DC supply! 
The regulator chip in the Astron was also fried as was a resistor and a cap.

I prefer to block the RF path on the Astron power leads by use of twisted DC 
cables, and Bead chokes as needed.  Use of balanced antennas is done with 
any Astron powered rigs I have, as well.

Stuart
K5KVH

Stuart
K5KVH