[RFI] Power Line Noise

K9MA k9ma at sdellington.us
Thu Apr 16 18:55:27 EDT 2020


That's basically right.  A horizontal antenna in free space has no 
vertically polarized component at all in the plane of the elements. 
However, slightly above or below that plane, there is a vertical 
component, which is maximum off the ends of the elements.

73,
Scott K9MA

On 4/16/2020 17:22, Joe wrote:
> Maybe thinking like this?
>
> OK the noise is vertical. and since close by it is higher above the 
> horizon?
> so then when the hf yagi is not pointing to the noise, it is more 
> closely matching the linear polarity of the elements?
>
> Joe WB9SBD
> Sig
> The Original Rolling Ball Clock
> Idle Tyme
> Idle-Tyme.com
> http://www.idle-tyme.com
> On 4/16/2020 5:16 PM, K9MA wrote:
>> On 4/16/2020 17:02, AA5CT wrote:
>>> re: "I went out today to track down a noise source, which on the
>>> HF bands appears to be coming from the east. "
>>>
>>>
>>> Scott, I give you even money odds that you found ANOTHER noise
>>> source on VHF, and not the one that was affecting you on HF (unless
>>> you already got it fixed, and that was it, in which case I lose hi hi).
>>
>> I doubt it. This source is just too incredibly loud at 135 MHz and 
>> close (maybe 300 feet from the antenna) that it can't possibly NOT be 
>> causing HF interference. I agree with your point, though. When 
>> tracking at VHF, I always hear lots of sources that are not the one 
>> causing the HF problem. I deal with that by relaying the noise from 
>> the HF receiver at home so that I can hear it while I'm out tracking. 
>> There is always a pattern to the fluctuations. When I find that they 
>> match, I know I've got the right source. This is the same principle 
>> as taking the "noise signature", without the expensive equipment. It 
>> has served me well.
>>
>> I didn't bother this time because the source is so ridiculously 
>> strong on VHF right out my front door.
>>
>> 73,
>>
>> Scott K9MA
>>
>

-- 
Scott  K9MA

k9ma at sdellington.us



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