[Amps] The Pin One Problem

[Jim Brown]

On 6/6/2013 2:22 PM, Peter Voelpel wrote:
> There is not much ham gear on the market with a pin 1.
> And in consumer audio equipment it is rather RCA then XLR.

The Pin One Problem applies to ALL equipment with a cable shield, and to 
both balanced and unbalanced wiring. See the tutorials.  It is simply 
CALLED The Pin One Problem because a guy working in pro audio (Neil 
Muncy, ex-W3WJE, now SK) figured it out, and that's what he chose to 
call it.

Power supplies can have Pin One-like problems -- many Astrons do. The 
green wire is required by law to go to the chassis. In reality, it goes 
to the mounting lug of a 4-wire terminal strip, which, in all three of 
the big Astron linear's I owned, was insulated from the chassis by 
paint.  It's been a while, but as I recall, another connection to that 
lug went to circuit common. In at least one of those units, the two 
major pieces of the chassis were also insulated from each other by 
paint.  I've heard more than one anecdotal report of Astron's having RFI 
issues.

73, Jim K9YC