[RFI] Power Line Radiated Interference Limits

[Charles Plunk]

My situation is different. In over 20 years of power pole rfi (gets 
fixed, good for months, another crops up), all of my "harmful" ones have 
been within 2-3 city blocks, usually less. An old 7.2kv 3 phase line 
runs right by my yard and up the street where most of the issues arise. 
The worst have been at the corners of my yard. Yea I know, dumb decision 
to buy near a 3 phase line but I was young and stupid, lol. It also 
limits tower height I can put up.

Last visit the power co lineman told me there maybe plans to re route 
the 3 phase. Sounded like Christmas to me but I am not holding my breath.

Currently, I am hearing maybe 3 sources that are likely over 1/2 mile (I 
say this because there are no 7.2kv lines within 1/2 mile in those 
directions) but they are weak and very intermittent thus not worth 
chasing for me. NB on lowest setting takes care of them. On HF they are 
almost always unnoticeable without NB. On 6m I can hear them at times 
with the yagi a bit better. Now that summer and high humidity has kicked 
in, rarely hear them even on 6.

Looking at the OP's QTH, a bicycle would maybe be a good idea for him. I 
have looked at the marine df unit. Would have bought one if I had not 
found the poles easily, once I acquired a technique to identify the 
correct noise :-)

73

Chuck
W4NBO



On 6/7/22 08:24, AA5CT wrote:
> re: "I have been most successful (without spending high dollar on rfi 
> gear)
> retransmitting the noise from my station receiver to a HT"
>
> I did that early on - used a local UHF repeater to relay the audio from
> the HF radio ... I've gotten good enough with the marine DF receiver
> (which I didn't have back when) that it isn't necessary any more!
>
> The KICKER is, when these 'sources' are found that are 1.74 miles
> away, they WILL be quite strong just feet away ... that's a 2nd
> good indicator! As you mention, a good number of poles produce
> low-level noise that isn't heard a couple hundred feet away nor
> at the home station QTH.
>
> On poles I can get within 12 inches of the 'ground'/earth wire, I
> make mental note of the signal strength/RF gain control setting
> on the marine DF receiver I use for each pole near the strong
> 'noise' maker ... correlating this later with which pole makes
> 'noise' at UHF using a UHF Yagi and my success level on finding
> these poles is 100%. Using a bicycle as transport really cuts
> down the time walking between poles to do this too, b/c, part
> of my learning/training process is to repeat this exercise
> over several different days, just to satisfy MY curiosity and
> desire to know I got the right pole.
>
> de AA5CT Jim
>
>