[Elecraft] Amplifier

[Jim Brown]

Problems like what Dennis is describing are often caused by failure to 
properly bond together all equipment in the shack, to bond that 
equipment to building ground, and to bond all building grounds together.

That said, the original KIO3 board fails to follow the good engineering 
practice of connecting cable shields to the shielding enclosure at the 
point of entry. This failure is, sadly, widespread in ham radio, 
computers, and consumer gear of all sorts. It is a MAJOR cause of hum, 
buzz, and RFI. It was brought to the attention of the world of pro audio 
by Neil Muncy, W3WJE (SK) in a landmark AES paper in 1994.

Problems caused by this design failure are greatly reduced by the proper 
bonding outlined above, and by the use of ferrite common mode chokes on 
wiring connected to the defective equipment. Proper bonding is described 
in the slides for a talk I've given to several ham conventions. The 
concepts have been incorporated into a new ARRL book on power and 
grounding by N0AX.

http://k9yc.com/GroundingAndAudio.pdf

73, Jim K9YC

On Fri,4/7/2017 12:42 AM, Vic Rosenthal wrote:
> Hmm, I am running 1.2+ kW to a dipole on the roof about 20 feet above my K3, which has no RF problems though other devices in my shack do!
>
> Vic 4X6GP
>
>> On 6 Apr 2017, at 19:28, Dennis Watkins <andromeda at nwi.net> wrote:
>>
>> I would suggest that a redesign on the K2/K3s would be a starting point.  The cheesy connectors on the back of the k3 will not stand up to a strong field  from a 1.5kw amp with the tower  mounted to the house. To much leakage for me.