Looking at the MECC map, I’m pretty sure the 500 KV line is +- 500 KV DC so that would by itself make it pretty quiet.
Sent from my iPad > On Jun 15, 2019, at 7:34 PM, Fred Jensen <[email protected]> wrote: > > I have never found a noise blanker to be of particular value, if any at all, > on general power line hash [the "grass" along the baseline of a panadapter. > At our prior home in Auburn CA, I had a 3-phase ~70 KV transmission line on > running across the lower end of the property that connected a series of > hydroelectric plants above and below us, and two 3-phase 112 KV transmission > lines on towers about 1/4 mile away. The 70 KV line was essentially quiet. > The 112 KV lines was perhaps S3-4 on 80 and had a fairly high frequency sound > ... I guess from the 3-separate phases with peaks occuring at 360 Hz. The K3 > NB was ineffective against it. With the level set high enough to affect the > noise level in the headphones, SSB was highly distorted and CW was chopped up. > > Here in NV, we are about 1/2 mile from a 500 KV 3-phase transmission line > connecting a power plant in Patrick NV to someplace up in OR, probably along > the Columbia. It is fairly quiet, S2-3 on 80, and again seems to be high > frequency enough that the K3 NB is ineffective. I've concluded that, while > technically it all is impulsive [arcs on voltage peaks], the peaks must > overlap enough and/or are of a high enough frequency that the NB either can't > find them or punches too many too big holes in the signal. It might be more > effective on noise from a single phase line, don't know. > > I rarely hear ignition noise from spark plugs anymore, however the landscape > maintenance crew showed up earlier this spring to aerate and de-thatch the > grass. Their aerator gizmo had an old 7 HP engine with strong ignition > noise. The NB took all of it out just fine at very low settings. > > 73, > Fred ["Skip"] K6DGW > Sparks NV DM09dn > Washoe County > >> On 6/14/2019 11:33 AM, Bob McGraw K4TAX wrote: >> David et al; >> >> My statement is almost word for word from the Elecraft K3 manual. And some >> from work done by Art Collins and company at Collins Radio. They prescribed >> the function of a Noise Blanker as follows: >> >> "The following operational requirements were kept in mind: >> >> 1. Reduction of ignition noise from vehicles. >> 2. Reduction of power line corona noise occurring at 120 CPS repetition >> rates. >> 3. Reduction of local thunderstorm disturbances. >> 4. And, in genera ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
