Greetings all.
We are considering moving to a location that is more friendly to ham radio and especially the performance of my K3. Here in our crowded neighborhood, I have regular S7 noise levels on all the lower HF bands. One home we found (and like) sits fairly close to high tension wires (ie like one lot away) however its in a much more rural area and likely to be more quite w.r.t. the usual man-made RF hash. Does anyone have any experience with living very close to high tension wires (not tool close, plenty of room for wire antennas without any danger.) Assuming nothing is "broken" is it likely to produce RF noise in the receiver? Is this something I should be concerned about? Thanks, and replies off list are appreciated to avoid the wrath of the list moderator <grin> Regards, Chris K1AY -- Life is like Linux - it never stands still. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
They are all different, one good way to find out is tune around on your car AM radio it will give you a good idea of rf noise level.JackW4GRJ
Sent via the Samsung Galaxy S®6 active, an AT&T 4G LTE smartphone-------- Original message --------From: Chris Hallinan <[hidden email]> Date: 3/15/2016 15:17 (GMT-05:00) To: "<[hidden email]>" <[hidden email]> Subject: [Elecraft] OT: K3 and High Tension Wires Greetings all. We are considering moving to a location that is more friendly to ham radio and especially the performance of my K3. Here in our crowded neighborhood, I have regular S7 noise levels on all the lower HF bands. One home we found (and like) sits fairly close to high tension wires (ie like one lot away) however its in a much more rural area and likely to be more quite w.r.t. the usual man-made RF hash. Does anyone have any experience with living very close to high tension wires (not tool close, plenty of room for wire antennas without any danger.) Assuming nothing is "broken" is it likely to produce RF noise in the receiver? Is this something I should be concerned about? Thanks, and replies off list are appreciated to avoid the wrath of the list moderator <grin> Regards, Chris K1AY -- Life is like Linux - it never stands still. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Chris Hallinan
Hi Chris!
It sounds like you're speaking of a distribution line. Do you have any idea that the voltage is? Is there more than one pole at each cross arm? It could be almost anything up to 240 KV ... or more. In my semi-rural area the voltage for distribution is 14.4 KV, which is pretty usual these days. Do you have any contact with other hams in the area? If so, what are their experiences with noise and dealing with the local power company? Some companies are very good about dealing with noise matters ...others are abysmal. Odds are that there are hams working for the power company's communications department if they do their own maintenance work. You might call your Public Service Commission and ask if they have any observations. Drive around the prospective neighborhood with your can radio tuned to the very top end of the BC band and see what you hear. I'm a retired power company communications technician and one of my jobs was to travel the state (Montana) as the line noise technician, so I feel like I'm qualified to comment. 73! Ken Kopp - K0PP 406-560-1555 On Tue, Mar 15, 2016 at 1:17 PM, Chris Hallinan <[hidden email]> wrote: > Greetings all. > > We are considering moving to a location that is more friendly to ham radio > and especially the performance of my K3. Here in our crowded neighborhood, > I have regular S7 noise levels on all the lower HF bands. One home we > found (and like) sits fairly close to high tension wires (ie like one lot > away) however its in a much more rural area and likely to be more quite > w.r.t. the usual man-made RF hash. > > Does anyone have any experience with living very close to high tension > wires (not tool close, plenty of room for wire antennas without any > danger.) Assuming nothing is "broken" is it likely to produce RF noise in > the receiver? Is this something I should be concerned about? > > Thanks, and replies off list are appreciated to avoid the wrath of the list > moderator <grin> > > Regards, > > Chris > K1AY > > -- > Life is like Linux - it never stands still. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Chris Hallinan
Others might be interested ...
We moved here to Sparks NV last Aug. Prior, we lived on 5 rural ac outside of Auburn CA for 38 years. Distribution lines were 12 KV, we had our own pole pig. There was a 69 KV tie line on wood poles between two hydro plants that cut across the south corner. There was two-circuit 112 KV line on metal towers about 1/4 mi to the east that had a tap across the south end of the property again about 1/4 mi. Never got any noise attributable to any of them. Now, the CalTrans sodium vapor street lamp at the Interstate off-ramp a mile away was a whole different story. It began to fail about 4 years ago, and I never could get them to replace the lamp and ballast. Over the years, the ambient noise rose slowly, almost all from the ubiquitous SMPS, most probably ours and our nearest neighbor. Growing up [a long time ago], a two circuit 230 KV line from Hoover Dam to Los Angeles ran a block away. Never any noise from them. We drove through the little town a couple of years ago, it is now a 500 KV line and no noise on my mobile driving on the road right beside it. My experience is that the HV lines [60 KV and up] get good maintenance and are almost universally quiet. Distribution lines not so much. Count the "fins" on the insulators to estimate the voltage. 69-70 KV are often on large umbrella type or short hanging ones. The 112 KV were hanging from ones with about 6 sections. 230 KV usually have 12-14 sections. 500 KV [and DC interties] have too many to count. On 3/15/2016 12:17 PM, Chris Hallinan wrote: > We are considering moving to a location that is more friendly to ham radio > and especially the performance of my K3. Here in our crowded neighborhood, > I have regular S7 noise levels on all the lower HF bands. One home we > found (and like) sits fairly close to high tension wires (ie like one lot > away) however its in a much more rural area and likely to be more quite > w.r.t. the usual man-made RF hash. > > Does anyone have any experience with living very close to high tension > wires (not tool close, plenty of room for wire antennas without any > danger.) Assuming nothing is "broken" is it likely to produce RF noise in > the receiver? Is this something I should be concerned about? ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Rose
On Tue,3/15/2016 12:56 PM, Rose wrote:
> It sounds like you're speaking of a distribution line. Do you have > any idea that the voltage is? Is there more than one pole at each > cross arm? It could be almost anything up to 240 KV ... or more. > In my semi-rural area the voltage for distribution is 14.4 KV, which > is pretty usual these days. I have a high voltage distribution line running along my property line that has not been a problem in the 10 years I've lived here, but there's been other power line noise around that's radiated from other poles. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
The 6 meter moonbouncer who lives up the hill from me told me he has no
problem from the high-tension line that runs right by his place but has experienced noise from the lower-voltage lines farther down the hill. I suspect that HT lines are probably less likely to have arcing than lower-voltage lines, simply because it would be a much bigger problem for the power company if they did. Alan N1AL On 03/15/2016 02:27 PM, Jim Brown wrote: > On Tue,3/15/2016 12:56 PM, Rose wrote: >> It sounds like you're speaking of a distribution line. Do you have >> any idea that the voltage is? Is there more than one pole at each >> cross arm? It could be almost anything up to 240 KV ... or more. >> In my semi-rural area the voltage for distribution is 14.4 KV, which >> is pretty usual these days. > > I have a high voltage distribution line running along my property line > that has not been a problem in the 10 years I've lived here, but there's > been other power line noise around that's radiated from other poles. > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Drawing from a decade of experience working as head of the PR department for a major electric utility (a long time ago), I’d like to suggest that arcing per se should not be a problem at any time with any power line if it is functioning properly. The individual transmission wires are spaced far enough apart that arcing shouldn’t be possible. Many utilities regularly wash down the insulators of high voltage transmission lines using specialized equipment that cleans condensed salt water fog off the insulators with deionized water (necessary to keep from zapping the guy running the spray nozzle). This is to prevent arcing between phases, which can otherwise occur in high humidity situations. If there’s noise coming from lower-voltage distribution lines down “down the hill” I would name the prime suspect as cable TV equipment that’s hung on the same utility poles as the power line. If the RF interference is caused by power line arcing, it’s going to get detected and fixed pretty quickly by the utility. If it’s there all the time, it very likely isn’t the power company at fault. (This discussion doesn’t include any consideration of Power Line Communication technologies, which are an identifiably different kind of interference.)
See: http://tdworld.com/overhead-distribution/insulator-washing-helps-maintain-reliability Lew N6LEW > On Mar 15, 2016, at 3:17 PM, Alan <[hidden email]> wrote: > > The 6 meter moonbouncer who lives up the hill from me told me he has no problem from the high-tension line that runs right by his place but has experienced noise from the lower-voltage lines farther down the hill. > > I suspect that HT lines are probably less likely to have arcing than lower-voltage lines, simply because it would be a much bigger problem for the power company if they did. > > Alan N1AL > > > On 03/15/2016 02:27 PM, Jim Brown wrote: >> On Tue,3/15/2016 12:56 PM, Rose wrote: >>> It sounds like you're speaking of a distribution line. Do you have >>> any idea that the voltage is? Is there more than one pole at each >>> cross arm? It could be almost anything up to 240 KV ... or more. >>> In my semi-rural area the voltage for distribution is 14.4 KV, which >>> is pretty usual these days. >> >> I have a high voltage distribution line running along my property line >> that has not been a problem in the 10 years I've lived here, but there's >> been other power line noise around that's radiated from other poles. >> >> 73, Jim K9YC >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] <mailto:[hidden email]> >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft <http://mailman.qth.net/mailman/listinfo/elecraft> > Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> > Post: mailto:[hidden email] <mailto:[hidden email]> > > This list hosted by: http://www.qsl.net <http://www.qsl.net/> > Please help support this email list: http://www.qsl.net/donate.html <http://www.qsl.net/donate.html> > Message delivered to [hidden email] <mailto:[hidden email]> Pasadena, CA DM04wd Elecraft K3-10 / KXV144 / XV432 Yaesu FT-7800 [hidden email] www.n6lew.us Generalized Law of Entropy: Sooner or later, everything that has been put together will fall apart. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Lew,
That's in direct conflict with everything I've seen from RFI engineers. Over the years, I've seen plenty of reports of hardware in the power system failing in a mode that causes it to arc. See http://www.arrl.org/power-line-noise for a great discussion of all sorts of RF noise, including power line noise. At least 10 years ago, I bought and read "AC Power Interference Handbook" by Marv Loftness, a field engineer who specialized in that work. He said that virtually all power line noise is caused by SOMETHING arcing. 73, Jim K9YC On Tue,3/15/2016 3:35 PM, Lewis Phelps wrote: > Drawing from a decade of experience working as head of the PR department for a major electric utility (a long time ago), I’d like to suggest that arcing per se should not be a problem at any time with any power line if it is functioning properly. The individual transmission wires are spaced far enough apart that arcing shouldn’t be possible. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
The Loftness book is the "go to" text on power line noise.
EVERY metal-to-metal junction is suspect. Lazy linemen hammer lag bolts straight in when installing cross arm braces. Metal steeples holding ground wire running down a pole arc and set poles on fire. The list is endless. 73 K0PP Retired power company noise chaser ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Jim Brown-10
Please reread the first sentence of my prior post, in which I qualified what I said with the phrase “…if it’s functioning properly.” What I said is NOT in conflict with your points. Power line noise is, de facto, the result of some sort of equipment failure. We agree on that. If something is arcing in a power distribution system, it’s because something is broken.
I suggest that we take go offline with any further discussion on the issue, since it is OT. Lew > On Mar 15, 2016, at 8:58 PM, Jim Brown <[hidden email]> wrote: > > Lew, > > That's in direct conflict with everything I've seen from RFI engineers. Over the years, I've seen plenty of reports of hardware in the power system failing in a mode that causes it to arc. See http://www.arrl.org/power-line-noise for a great discussion of all sorts of RF noise, including power line noise. At least 10 years ago, I bought and read "AC Power Interference Handbook" by Marv Loftness, a field engineer who specialized in that work. He said that virtually all power line noise is caused by SOMETHING arcing. > > 73, Jim K9YC > > On Tue,3/15/2016 3:35 PM, Lewis Phelps wrote: >> Drawing from a decade of experience working as head of the PR department for a major electric utility (a long time ago), I’d like to suggest that arcing per se should not be a problem at any time with any power line if it is functioning properly. The individual transmission wires are spaced far enough apart that arcing shouldn’t be possible. > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Lew Phelps N6LEW Pasadena, CA DM04wd Elecraft K3-10 / KXV144 / XV432 Yaesu FT-7800 [hidden email] www.n6lew.us Generalized Law of Entropy: Sooner or later, everything that has been put together will fall apart. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Jim Brown-10
He did say that he was head of the PR department.
On 3/15/2016 8:58 PM, Jim Brown wrote: > Lew, > > That's in direct conflict with everything I've seen from RFI engineers. Over > the years, I've seen plenty of reports of hardware in the power system failing > in a mode that causes it to arc. See http://www.arrl.org/power-line-noise for > a great discussion of all sorts of RF noise, including power line noise. At > least 10 years ago, I bought and read "AC Power Interference Handbook" by Marv > Loftness, a field engineer who specialized in that work. He said that > virtually all power line noise is caused by SOMETHING arcing. > > 73, Jim K9YC > > On Tue,3/15/2016 3:35 PM, Lewis Phelps wrote: >> Drawing from a decade of experience working as head of the PR department for >> a major electric utility (a long time ago), I’d like to suggest that arcing >> per se should not be a problem at any time with any power line if it is >> functioning properly. The individual transmission wires are spaced far enough >> apart that arcing shouldn’t be possible. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
The arcing that causes RFI is usually not from the power lines
themselves, but various pieces of poorly bonded hardware NEAR the power lines. 73, Scott K9MA On 3/16/2016 09:18, Wes (N7WS) wrote: > He did say that he was head of the PR department. > > On 3/15/2016 8:58 PM, Jim Brown wrote: >> Lew, >> >> That's in direct conflict with everything I've seen from RFI >> engineers. Over the years, I've seen plenty of reports of hardware in >> the power system failing in a mode that causes it to arc. See >> http://www.arrl.org/power-line-noise for a great discussion of all >> sorts of RF noise, including power line noise. At least 10 years ago, >> I bought and read "AC Power Interference Handbook" by Marv Loftness, >> a field engineer who specialized in that work. He said that virtually >> all power line noise is caused by SOMETHING arcing. >> >> 73, Jim K9YC >> >> On Tue,3/15/2016 3:35 PM, Lewis Phelps wrote: >>> Drawing from a decade of experience working as head of the PR >>> department for a major electric utility (a long time ago), I’d like >>> to suggest that arcing per se should not be a problem at any time >>> with any power line if it is functioning properly. The individual >>> transmission wires are spaced far enough apart that arcing shouldn’t >>> be possible. >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] -- Scott Ellington K9MA Madison, Wisconsin, USA [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Lewis Phelps
On Wed,3/16/2016 6:27 AM, Dave Olean wrote:
> If the RF interference is caused by power line arcing, it’s going to > get detected and fixed pretty quickly by the utility. If it’s there > all the time, it very likely isn’t the power company at fault. Here in Northern California where PG&E is our power utility, it is usually possible to get them to send a crew out to investigate and document an issue, but nearly impossible to get it fixed. NI6T, an EE with considerable experience in the matter, managed to get cozy with at least one PG&E investigator, and learned that managers of the department that FIXES these problems is rewarded in proportion to their annual budget that is NOT spent. In other words, they are incentivized to NOT fix problems. Another local ham who is an attorney found that contacting the state agency regulating PGE got his problems fixed when PG&E had previously failed to do so. Since the experience of both of these hams is directly related to business practices and the profit motive, one might reasonably suspect that they are at least somewhat universal throughout the industry. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Always be ready to play the "public utilities commission" card.
On 3/16/2016 9:11 AM, Jim Brown wrote: > Another local ham who is an attorney found that contacting the state > agency regulating PGE got his problems fixed when PG&E had previously > failed to do so. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Alan Bloom
Actually, there have been some problems from those high voltage lines. I
believe these are on the order of 300kV. Official word from PG&E is that they will not make any repairs solely for RFI because it's too expensive to do it. 73, Josh W6XU On 3/15/2016 3:17 PM, Alan wrote: > The 6 meter moonbouncer who lives up the hill from me told me he has > no problem from the high-tension line that runs right by his place but > has experienced noise from the lower-voltage lines farther down the hill. > > I suspect that HT lines are probably less likely to have arcing than > lower-voltage lines, simply because it would be a much bigger problem > for the power company if they did. > > Alan N1AL ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
You should copy this to the RFI mail list, so the ARRL folks are made
aware that has become policy for a power company... -- 73's, and thanks, Dave (NK7Z) For software/hardware reviews see: http://www.nk7z.net For MixW support see: https://groups.yahoo.com/neo/groups/mixw/info For SSTV help see: http://groups.yahoo.com/neo/groups/MM-SSTV/info On Wed, 2016-03-16 at 11:18 -0700, Josh Fiden wrote: > Actually, there have been some problems from those high voltage > lines. I > believe these are on the order of 300kV. Official word from PG&E is > that > they will not make any repairs solely for RFI because it's too > expensive > to do it. > > 73, > Josh W6XU > > On 3/15/2016 3:17 PM, Alan wrote: > > > > The 6 meter moonbouncer who lives up the hill from me told me he > > has > > no problem from the high-tension line that runs right by his place > > but > > has experienced noise from the lower-voltage lines farther down the > > hill. > > > > I suspect that HT lines are probably less likely to have arcing > > than > > lower-voltage lines, simply because it would be a much bigger > > problem > > for the power company if they did. > > > > Alan N1AL > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by K9MA
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. :) 73, Jim ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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. :) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
I have a 300KV distribution line about 0.5 miles from my QTH, and have not had any significant issues. About every month or two I walk along two miles of the power line with my KX3 checking for increased noise on various bands that I normally use. Only once in eight years did I hear anything and it was only about 3 to 4dB above my normal noise levels. A week later I checked and didn’t hear it. Could have been the power line or could have been something else.
73, Bob Nobis - N7RJN [hidden email] > On Mar 16, 2016, at 16:51, Fred Jensen <[hidden email]> wrote: > > 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. :) > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
In reply to this post by Alan Bloom
On 3/15/2016 3:17 PM, Alan wrote:
> I suspect that HT lines are probably less likely to have arcing than > lower-voltage lines, simply because it would be a much bigger problem > for the power company if they did. Arcing represents a loss of energy, which for most power utilities means loss of revenue. For a while, a member of the extended family dated a power line tech whose job it was to "sniff" the insulators along a 240KV transmission line for the local utility on a regular basis. It takes strange people do that job. :) -- -- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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