[Elecraft] Elecraft: RFI Problems

[Stephen W. Kercel]

Vic:

Certainly it is the case that the remedy that solves one emi problem might 
make another one worse. That is what makes emi so difficult.

73,

Steve
AA4AK
Brunswick ME


At 04:33 PM 1/29/2005 -0800, you wrote:
>Stephen W. Kercel wrote:
>
>>If radiation from the exterior surface of the antenna feedline were the 
>>only mechanism that causes emi, then you would be right, choking it off 
>>would solve the emi problem. The energy in the transmission line would be 
>>radiated by the antenna or turned into heat by either the line losses or 
>>by the losses in the materials used to make up the choke. However, emi 
>>can be caused by many other mechanisms, and as one other poster to the 
>>reflector has reported, improving his RF ground substantially mitigated 
>>his problem.
>
>I understand that there are other paths, such as pickup on the 
>power/phone/speaker lines directly from the antenna, etc.  This is why I 
>suggested that the fellow use ferrites on the power leads to his stereo 
>and modem.  My point about choking off RF on the feedline was just that an 
>RF-free feedline is easier to achieve (unless you are using a random wire 
>antenna) than an RF ground.
>
>I have to say that the guy who reported an improvement may have gotten an 
>improvement -- but not from the fact that his rig had a better ground, 
>rather from the change in the RF environment that his ground system 
>caused.  In other words, it might make it better, but it also could make 
>it worse.
>
>--
>73,
>Vic, K2VCO
>Fresno CA
>http://www.qsl.net/k2vco
>