[Elecraft] [PX3] Carrier Null

[Don Wilhelm]

Joel and all,

Use BONDING rather than "Grounding"

You may create more noise problems by attempting to "ground" everything.
"Ground" is not a sink for noise and RFI problems, it is only protection 
for AC mains safety and lightning surges.  Grounding will not carry away 
noise that is picked up on the shields of connecting cables, and in some 
cases may even make it worse.  Yes, you should have a good Mother Earth 
ground in the hamshack, but it will likely not help with noise, hum and 
buzz problems.

Take the advice of Jim Brown K9YC and BOND the equipment enclosures 
together.
In other words, connect the KX3 and PX3 enclosures together with a heavy 
wire or braid.

What you accomplish by bonding is to take a major portion of the noise 
that would appear on the cable shield(s) and conduct it to the outside 
of the enclosure so that it does not get onto the ground plane of the PC 
board.

We did not have that problem years ago when all connectors were mounted 
to a metal enclosure.  The outside of the cable shield braid was 
connected to the outside of the enclosure.
But modern construction techniques connect the shields of cables to the 
ground plane of the PC board and not to the enclosure.  So any noise 
present on the outside of the cable shield is conducted into the 
electronics.  The bonding wire eliminates much of that "pin 1 problem".

73,
Don W3FPR



On 6/3/2016 6:18 AM, Joel Black wrote:
> Someone on this list or the Yahoo reflector posted a picture of a BNC star washer with a ground lug on it. I’m going to order one of those and also put some kind of ground lug on the PX3 and make sure I have a good ground in the shack and *try* to eliminate any ground loop issues between the KX3 and PX3.
>
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