[RFI] Line noise vs Frequency

[K9MA]

I've been doing just that for years, and agree completely with Chuck 
that it's a key. You otherwise will waste your time tracking the wrong 
sources.

Put the station HF receiver in AM mode, turn the AGC off, reduce RF gain 
so it doesn't overload, and adjust AF gain so that it doesn't overload 
the HT.

73,
Scott K9MA


On 8/10/2021 12:54 PM, Charles Plunk wrote:
>
> Sounds like my neighborhood. In locating my last source (a horrible 
> 20-30 over S9 on 75m), the most significant break through for me was 
> matching the noise pattern to what I was hearing in my hf receiver. I 
> accomplished this be retransmitting the hf receivers audio to one ht, 
> while I df'ed on another ht on 2m AM and a portable 4 element yagi. 
> With the 2 HT's in tow, when the 2 synced in noise pattern I knew I 
> was at the correct pole. Next time I may try stereo headphones with 
> one ht on one ear and the other on the other ear to reduce traffic 
> noise etc.
>
> Prior, I made the big mistake of df'ing for just max noise at the 
> poles. These 7.2kv lines radiate a strong signal on 2m near almost 
> every pole (corona?) but that was not what I was hearing on hf. To my 
> surprise the target source was almost obscured by this noise with the 
> portable 2m AM. Also, I waited to hunt until the target source had a 
> distinctive pattern as it tended to vary and even go away with 
> variances in weather primarily humidity.
>
> I also have a FT-817 (actually 2) to df in lower or higher frequencies 
> as needed. And adding to my portable yagis/  portable loops as I get 
> time to build them.
>
> Chuck
>
> W4NBO
>
> On 8/10/21 9:54 AM, Pete Smith N4ZR wrote:
>> Thanks, guys - I went out with my HF DF rig, and the one thing I'm 
>> pretty sure of is that the point source is not nearby.  Anywhere 
>> along the neighborhood-level feed that runs along the West side of my 
>> property I get a similarly high level, with no discernable local peak 
>> at a particular pole, so my suspicion is that the source is further 
>> down the line in someplace where I don't have access.  I have sent a 
>> recording and a request for help to my local power company guy, who 
>> tries very hard and has good gear but relatively little knowledge.  
>> The line is probably 60 years old, dating to this subdivision's 
>> beginnings, and has required a lot of hardware replacement recently.
>>
>> 73, Pete N4ZR
>> Check out the new Reverse Beacon Network
>> web server at <http://beta.reversebeacon.net>.
>> For spots, please use your favorite
>> "retail" DX cluster.
>>
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi


-- 
Scott  K9MA

k9ma at sdellington.us