[TenTec] Station power supply??

[Jim Brown]

On 9/5/2012 8:31 AM, Don Allen wrote:
> I'm sure the discussion will continue, as it has lasted ever since 
> Astron made the running production change to their supplies. 

I'm sure every engineer who has investigated the issue will agree that 
the thing that Astron has done wrong is to build products where PAINT 
interferes with proper bonding of the Green Wire to the chassis (as 
required by LAW, for safety), and of the connections of one part of the 
chassis to another.

What they have done RIGHT is to build power supplies that do NOT REQUIRE 
that V- be bonded to the chassis to work properly, but make it easy for 
a user to make that bond if he wants to.  Note also that this issue with 
modulation of V- by an AM or SSB signal is only one reason for NOT bonding.

Another VERY good reason is that if V- is NOT bonded, a rather simple 
common mode choke can be used on the two-conductor cable to kill any RFI 
either into or out of the box. But if V- is bonded to the chassis, 
return current will divide by Ohm's Law between all other ground paths 
in the shack, so a choke on the two conductors is likely to saturate.

73, Jim K9YC