[Elecraft] OT: K3 and High Tension Wires

Fred Jensen k6dgw at foothill.net
Wed Mar 16 19:51:06 EDT 2016


Yes, and buried in there is the reason why it is so hard to get the 
power company's attention for distribution line noise [12-14 KV] ... the 
loss to them is minuscule compared to other costs.

With no disparagement of power linemen intended, distribution is almost 
universally on wood poles if it isn't underground.  They're assembled 
on-site to more or less standard configurations, and the hardware often 
reclines in the back of their trucks exposed to the weather and 
oxidation for weeks [or months].  The standard configurations usually 
require some [or a lot] of on-site "special engineering" to satisfy the 
real-time need at a given pole.

Above distribution voltages the lines are engineered.  Towers are built 
to fairly exacting standards and erected by professional riggers.  If 
something is wrong, they go back to the engineers.  The power company 
*does* have an interest in corona and leakage losses at 100 KV and 
above.  I think that's why most really high voltage lines are quiet.

RFI from distribution circuits is really an FCC [or other national comm 
regulator] responsibility ... they're incidental radiators under Part 15 
in the US.  That said, the K3 NB took out almost all the distribution 
line noise I had when we were in CA ... it failed on the CalTrans street 
lamp, but so did everything else. :-)  I rarely used NR, just couldn't 
find the sweet spot to make it effective.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 3/16/2016 4:16 PM, Jim Brown wrote:
> On Wed,3/16/2016 9:08 AM, Scott Ellington wrote:
>> The arcing that causes RFI is usually not from the power lines
>> themselves, but various pieces of poorly bonded hardware NEAR the
>> power lines.
>
> Right. But most engineers would view the lines and that hardware as a
> "power distribution system," and an attempt to separate the two a game
> of semantics. A chain is only as strong as its weakest link. :)



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