K3 - SignaLink USB
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His website says UK sales ONLY.
On Fri, May 31, 2013 at 3:04 PM, Chris, G5VZ <[hidden email]> wrote: > I don't know exactly what G3TPW is doing these days but M0ZIM is selling a > commercial cobwebb: see http://www.mcr666.com/sales1/** > ham-radio/4-meter-70-meg-base-**vertical-antenna/cobwebb-**antenna/<http://www.mcr666.com/sales1/ham-radio/4-meter-70-meg-base-vertical-antenna/cobwebb-antenna/> > > Usual disclaimers - I do have one of these antennas but otherwise no > interest in the operation. I think Mark will ship worldwide. > > Chris > G5VZ / WG5VZ > > On 31/05/2013 22:44, Bill Blomgren wrote: > >> Exactly - Not sure what is going on with the "commercial" version's >> guy... I suspect that is a side venture, and 'real work' probably has him >> tied up. >> >> It's either that, or he doesn't want to fight with exchange rates, >> shipping out of olde blighty, and all that stuff. >> >> That said.. I'm wondering if there are other baluns that might have >> better performance up as far as say 6 meters... <heh> - allowing a 6th >> band... >> ----- Original Message ----- >> From: [hidden email] >> To: Bill Blomgren >> Cc: [hidden email] >> Sent: Friday, May 31, 2013 6:54 AM >> Subject: Re: [Elecraft] cobweb antenna >> >> >> Hello Bill, >> >> >> >> I have no intent to denigrate the design and functionality of the >> "Cobweb" style antenna but......... >> >> >> >> Several years ago I was inclined to acquire the G3TPW commercial >> version of the "CobWebb" antenna, I found the website ( www.g3tpw.co.u ) >> and sent an email asking how to order, method of payment & shipping >> charges, etc. Got no response......I thought maybe there was some problem >> with the 1st email attempt so I sent another.....still no response. So I >> sent an inquiry via regular mail, including a self addressed (with postage) >> return envelope......no reply whatsoever....... >> >> >> >> So I can't comment on how well the G3TPW version functions......but in >> consideration of my above described experience, maybe you should limit your >> effort to a homebrew version. >> >> >> >> Also, later I had good results with the homebrew version of the >> Buddipole, built from free instructions on W3FF's homepage ( >> https://sites.google.com/site/**w3ffhomepage/<https://sites.google.com/site/w3ffhomepage/>). But back then I was doing more portable ops and since the commercial >> version is more sturdy I decided to get one......saw one being offered on >> ebay so I bid and won the auction. Eventually I lost one small bit and >> needed a replacement part so I contacted W3FF and got very fast >> response....even though I hadn't purchased direct from them. >> >> >> >> So I've decided customer service is just as important as functionality >> when deciding which products to acquire. Just my opinion............... >> >> >> >> Rich K2CPE >> >> K2 #1102 >> >> >> >> >> >> >> >> >> ------------------------------**------------------------------** >> ------------------ >> >> >> From: "Bill Blomgren" <[hidden email]> >> To: [hidden email] >> Sent: Thursday, May 30, 2013 10:27:22 PM >> Subject: [Elecraft] cobweb antenna >> >> >> I'm still in the "pre-purchase" stage.. but I'm sort of thinking that >> the K3 >> is where I'm going to end up.. Possibly with the preamp...and then >> there is >> the big problem: what to make it to the air with..... >> >> The idea of starting off with the buddipole system is out there - and >> very >> possible... >> >> I've also been reading up on the plusses and minuses of many of the >> alternatives that may be possible in an apartment life... >> >> One is the magnetic loop - which is a tad pricey with the vac. >> variable -- >> lots of copper, and the need to tune the thing every time you change >> frequency - and not just antenna tuner stuff - as in changing the cap >> on the >> antenna itself. It is a very high q (and thus voltage and current) >> critter...Rube Golberg figured out how to do that.. motors with long >> screw >> drives into a sealed box with the cap inside..with very high voltages >> there... and thus requiring altitude for safety.. >> >> I came across a nifty square thing called a cobweb, which is more or >> less >> semi-flat over 4-5 bands... is very light..and can be made of pvc pipe >> or >> possibly fiber glass because it just has 5 wires in a big square.. One >> antenna to cover 20 17 15, 12 and 10 meters sounds interesting.. One >> of the >> designs even works on 6, but has higher losses... (That may be the >> baluns >> they use for a 4-1 impedance match and to go unbalanced... >> >> Has anyone tried one of these critters, and if so, is the Elecraft >> happy >> with it? >> >> >> ______________________________**______________________________**__ >> 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].**net <[hidden email]> >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> ______________________________**______________________________**__ >> 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].**net <[hidden email]> >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> > ______________________________**______________________________**__ > 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].**net <[hidden email]> > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > 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 |
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Greg, all,
I see his web site has now been updated and there are options for international shipment - I was sure he'd told me he had sold to USA and Canada in the recent past. Chris G5VZ / WG5VZ On 01/06/2013 03:07, Greg wrote: > His website says UK sales ONLY. > > > On Fri, May 31, 2013 at 3:04 PM, Chris, G5VZ <[hidden email] > <mailto:[hidden email]>> wrote: > > I don't know exactly what G3TPW is doing these days but M0ZIM is > selling a commercial cobwebb: see > http://www.mcr666.com/sales1/ham-radio/4-meter-70-meg-base-vertical-antenna/cobwebb-antenna/ > > Usual disclaimers - I do have one of these antennas but otherwise > no interest in the operation. I think Mark will ship worldwide. > > Chris > G5VZ / WG5VZ > > On 31/05/2013 22:44, Bill Blomgren wrote: > > Exactly - Not sure what is going on with the "commercial" > version's guy... I suspect that is a side venture, and 'real > work' probably has him tied up. > > It's either that, or he doesn't want to fight with exchange > rates, shipping out of olde blighty, and all that stuff. > > That said.. I'm wondering if there are other baluns that might > have better performance up as far as say 6 meters... <heh> - > allowing a 6th band... > ----- Original Message ----- > From: [hidden email] <mailto:[hidden email]> > To: Bill Blomgren > Cc: [hidden email] <mailto:[hidden email]> > Sent: Friday, May 31, 2013 6:54 AM > Subject: Re: [Elecraft] cobweb antenna > > > Hello Bill, > > > > I have no intent to denigrate the design and functionality > of the "Cobweb" style antenna but......... > > > > Several years ago I was inclined to acquire the G3TPW > commercial version of the "CobWebb" antenna, I found the > website ( www.g3tpw.co.u ) and sent an email asking how to > order, method of payment & shipping charges, etc. Got no > response......I thought maybe there was some problem with the > 1st email attempt so I sent another.....still no response. So > I sent an inquiry via regular mail, including a self addressed > (with postage) return envelope......no reply whatsoever....... > > > > So I can't comment on how well the G3TPW version > functions......but in consideration of my above described > experience, maybe you should limit your effort to a homebrew > version. > > > > Also, later I had good results with the homebrew version of > the Buddipole, built from free instructions on W3FF's homepage > ( https://sites.google.com/site/w3ffhomepage/ ). But back then > I was doing more portable ops and since the commercial version > is more sturdy I decided to get one......saw one being offered > on ebay so I bid and won the auction. Eventually I lost one > small bit and needed a replacement part so I contacted W3FF > and got very fast response....even though I hadn't purchased > direct from them. > > > > So I've decided customer service is just as important as > functionality when deciding which products to acquire. Just my > opinion............... > > > > Rich K2CPE > > K2 #1102 > > > > > > > > > ------------------------------------------------------------------------------ > > > From: "Bill Blomgren" <[hidden email] > <mailto:[hidden email]>> > To: [hidden email] <mailto:[hidden email]> > Sent: Thursday, May 30, 2013 10:27:22 PM > Subject: [Elecraft] cobweb antenna > > > I'm still in the "pre-purchase" stage.. but I'm sort of > thinking that the K3 > is where I'm going to end up.. Possibly with the > preamp...and then there is > the big problem: what to make it to the air with..... > > The idea of starting off with the buddipole system is out > there - and very > possible... > > I've also been reading up on the plusses and minuses of > many of the > alternatives that may be possible in an apartment life... > > One is the magnetic loop - which is a tad pricey with the > vac. variable -- > lots of copper, and the need to tune the thing every time > you change > frequency - and not just antenna tuner stuff - as in > changing the cap on the > antenna itself. It is a very high q (and thus voltage and > current) > critter...Rube Golberg figured out how to do that.. motors > with long screw > drives into a sealed box with the cap inside..with very > high voltages > there... and thus requiring altitude for safety.. > > I came across a nifty square thing called a cobweb, which > is more or less > semi-flat over 4-5 bands... is very light..and can be made > of pvc pipe or > possibly fiber glass because it just has 5 wires in a big > square.. One > antenna to cover 20 17 15, 12 and 10 meters sounds > interesting.. One of the > designs even works on 6, but has higher losses... (That may > be the baluns > they use for a 4-1 impedance match and to go unbalanced... > > Has anyone tried one of these critters, and if so, is the > Elecraft happy > with it? > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > <mailto:[hidden email]> > > This list hosted by: http://www.qsl.net > Please help support this email list: > http://www.qsl.net/donate.html > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > <mailto:[hidden email]> > > This list hosted by: http://www.qsl.net > Please help support this email list: > http://www.qsl.net/donate.html > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > <mailto:[hidden email]> > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ 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 |
Twisted Pair RS232 leads, particularly [K2] (was: EARC End Fed 6-40 question)
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In reply to this post by Jim Brown-10
I could understand your suggestion wrt to twisted pair on the K2 serial
cable if it were using RS-423 and therefore balanced receivers with no parallelling of the signal returns. However, how does twisted pair really help if the return in the twisted pair is in parallel with that for the other signal lines and any functional earth bonding strap between the two pieces of equipment? Of course, PCs don't use RS-423, so one could only implement that for data to the K2. Jim Brown wrote: > > Another issue, if you're using a K2, is that the serial cable that was > built from instructions (and the parts provided) used parallel > conductors rather than twisted pair. That was a VERY poor design choice > -- parallel conductors are very susceptible to RF and other noise, and > twisted pair inherently rejects RFI and noise. That's why CAT5/6/7 > cable is twisted pair. -- David Woolley Registered owner K2 06123 ______________________________________________________________ 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 |
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In reply to this post by Joe Subich, W4TV-4
Joe Subich, W4TV wrote:
The near field (basically within the range where it follows an inverse cube law) can be predominantly magnetic or predominantly electric in nature. Whilst the ratio of electric and magnetic fields in the far field is constrained to 377 ohms per square, that is not true in the near field. > > No. If the field is not able to couple to nearby objects, it is not > able to radiate (couple to) distant receivers. The statement flies > completely in the face of physics. > -- David Woolley Registered owner of K2 06123 ______________________________________________________________ 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 |
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In reply to this post by Jim Brown-10
Jim,
Thanks for the links interesting... This is the Elecraft list so yes my KX3 with internal ATU and another without and T1 ATU finds a match easily, same for K1 or K2 with this antenna. You do not have to buy the antenna at all ... you can build your own from a few parts as I did. A stanchion floor plate (so it fits on top of the mast), an Aluminium centre plate, some U bolts, lengths of hose pipe to fit over 4 poles so you do not crush them in the u blots, a couple dozen tie-wraps (for the wires) and some speaker wire (or zip cord) and a 8 turn RG213 choke at the feed point was all that was needed. I am sure the website links have all the homebrew info. You can buy a commercial version obviously as well. If you do not have a lot of horizontal space (or an attic for all those stealth antennas) which is why is was designed, it works fine and it can be put up and brought down pretty quickly especially if you have a restriction on permanent antennas. If you are so inclined you could create pivots on the poles so the antenna would close up on itself a bit like a rotary washing line? I used fishing poles so mine basically came apart easily after use. No mystery about the design either it is basically a set of nested 1/2 wave dipoles in a halo's in a square all fed from a common feedpoint. One side is approximately 1/4 of the size of the lowest frequency you want to use. You got a small apartment, back garden or 'yard' in US and it can mean getting on air. It is a 'balanced antenna' so that means no radials etc.. Oddly enough mine worked fine (20ft TV pole) on 160m and 472KHz/500KHz with a few modifications... first I slid a section of PVC between the pole and the H&K wall brackets so the pole was better insulated, then I jumpered both the upper feed points to the pole from the connector box (just a series of chocolate blocks for the wires) at the top then fed the pole from the bottom against ground. The antenna then acted as a short vertical with a big capacitance hat. 72 Dom M1KTA On 31/05/13 17:55, Jim Brown wrote: > On 5/30/2013 7:27 PM, Bill Blomgren wrote: >> >> Has anyone tried one of these critters, and if so, is the Elecraft >> happy with it? > > Why BUY an antenna when you can very easily build one for a lot less > money that will likely work better? Here are some articles by hams > who have done a lot with only a little bit of space. The first is by > AC0C, who built a complete antenna system in the attic of his apartment! > > http://www.kcdxclub.com/Stealth%20Antennas-r1%20-%20AC0C%20-%202-2009.pdf > > 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 |
Re: Twisted Pair RS232 leads, particularly [K2]
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In reply to this post by David Woolley (E.L)
On 6/1/2013 3:05 AM, David Woolley (E.L) wrote:
> However, how does twisted pair really help if the return in the > twisted pair is in parallel with that for the other signal lines and > any functional earth bonding strap between the two pieces of equipment? Twisting strongly rejects magnetic coupling from an interfering source to the differential circuit. In the near field of a current source, the magnetic field is strongly dominant. Twisting also provides some rejection (at RF) of an electromagnetic field in the differential circuit. Most end-fed antennas have a strong current peak at the feedpoint; if it's end fed wire that ends in the shack, there will be a very strong magnetic field. I encountered this with a K2 feeding an end fed wire on 80 and 160 that shut down my computer at about 10 watts! Changing that cable to unshielded twisted pairs, and terminating the return of each pair to the shell of the DB9 at both ends, allowed me to run my Titan 425 power amp at 1kW. The antenna and the serial cable were within about 1.5 m of each other. As part of my tests of that solution, I ran legal limit into that antenna on all bands up through 10M. No cable shield was required through 17M, but shielding was needed at 15M and above. BTW -- as part of an EMC workshop I led for Audio and Video professionals, I demonstrated that unshielded twisted pair and shielded twisted pair were equivalent in their ability to reject RFI in balanced microphone circuits all the way up to the 900 MHz and 1.6 GHz bands used for cell phones in the US. Neither cable was perfect, both had slight vulnerability, but neither was clearly superior. For the demonstration, I keyed a ham talkie on 2M, 220 MHz, and 440 MHz, a Nextel phone (TMDA 900 MHz) and a borrowed 1.6 GHz phone that also ran TMDA, moving the interference source near the vulnerable equipment and moving it along the cable for several wavelengths. Does bonding help? Absolutely! Sadly, proper bonding of equipment is rare -- hams are fearful of creating "ground loops," an entirely fictional boogie-man. I have long advocated (written and lectured) for short fat copper bonding from chassis to chassis of every piece of gear in the shack, and from chassis to chassis of every piece of gear that has any interconnection between them, and from some common point of all of that to all other grounds in a premises. 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 |
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In reply to this post by David Woolley (E.L)
Whether the field is predominately magnetic or electric, it must still couple to the environment around it or the antenna *will not* radiate. whilst the same folding that is responsible for the low feed impedance and low efficiency will result in more cancellation close to the antenna than at greater distances, the antenna will still have *significant coupling* to any conductive element in its immediate environment (near field). If that were not true, yagi antennas would be impossible and phased arrays would be easy to design because one could ignore mutual impedance. 73, ... Joe, W4TV On 6/1/2013 6:23 AM, David Woolley (E.L) wrote: > Joe Subich, W4TV wrote: > > The near field (basically within the range where it follows an inverse > cube law) can be predominantly magnetic or predominantly electric in > nature. Whilst the ratio of electric and magnetic fields in the far > field is constrained to 377 ohms per square, that is not true in the > near field. > >> >> No. If the field is not able to couple to nearby objects, it is not >> able to radiate (couple to) distant receivers. The statement flies >> completely in the face of physics. >> 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 |
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Joe is right...
Maxwell's equations relate time dependant electrical and magnetic fields. If B is changing with time, E cannot equal zero everywhere in space and if E is changing with time, B cannot be zero everywhere in space (otherwise you can not fulfill the two equations for the "curl" of the fields). So, no B without E and reverse (if there is some time dependance which is the case for hf). If you calculate the field strength for a given current distribution, you can make some simplifications that lead to field components changing with the inverse of the cube of the distance (1/r^3), field components changing with one over the square of the distance (1/r^2) and components changing with 1/r (the far field radiated by the structure). For short distances to the antenna, the 1/r^3 and the 1/r^2 terms are the dominating ones and form the near fields. The difference between an elementary electrical and a magnetic dipole is that, for very short distances to the antenna ("reactive near field", less than about 1/6 wavelength), the leading term (the 1/r^3 term of the field expansion) is a purely electrical field for the electrical antenna and a purely magnetic field for the magnetic antenna. So, the most efficient coupling for the magnetic antenna would be a conducting loop (if properly oriented), but a straight conductor for the electrical antenna. There is some limited control for this coupling to nearby conductors by "switching from electrical to magnetic", but the next important term for rather short distances is the 1/r^2 term of the field expansion, and both the magnetic and the electrical elemetary dipoles show both an electrical and a magnetic field component with this 1/r^2 behaviour. So both antennas can couple to straight conductors or loops via this part of the field in the same manner, only the absolute amount of coupling (coupling constant) might be different. Conclusion: you have some (limited) control on the 1/r^3 part, which is purely magnetic for a magnetic antenna and purely electrical for an electrical antenna, but you will have this "1/r^2 coupling" for both a magnetic and an electrical antenna, meaning you can not generally eliminate the coupling to nearby conductors just by using a "dominantly magnetic antenna" or a "dominantly electrical antenna". Vy 73 Ralf, DL6OAP Am 01.06.2013 um 19:46 schrieb "Joe Subich, W4TV" <[hidden email]>: > > Whether the field is predominately magnetic or electric, it must > still couple to the environment around it or the antenna *will not* radiate. whilst the same folding that is responsible for the low > feed impedance and low efficiency will result in more cancellation > close to the antenna than at greater distances, the antenna will > still have *significant coupling* to any conductive element in its > immediate environment (near field). If that were not true, yagi > antennas would be impossible and phased arrays would be easy to > design because one could ignore mutual impedance. > > 73, > > ... Joe, W4TV > > > On 6/1/2013 6:23 AM, David Woolley (E.L) wrote: >> Joe Subich, W4TV wrote: >> >> The near field (basically within the range where it follows an inverse >> cube law) can be predominantly magnetic or predominantly electric in >> nature. Whilst the ratio of electric and magnetic fields in the far >> field is constrained to 377 ohms per square, that is not true in the >> near field. >> >>> >>> No. If the field is not able to couple to nearby objects, it is not >>> able to radiate (couple to) distant receivers. The statement flies >>> completely in the face of physics. >>> > ______________________________________________________________ > 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 ______________________________________________________________ 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 |
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Actually, you have confirmed my point by showing that, in the near
field, magnetic loops and electric dipoles interact very differently, thus may have rather different EMC behaviour. I was not disputing that the far field component interacts at short distances. I was only saying that the near field component can make the total interaction significantly different. -- David Woolley Registered owner of K2 06123 Ralf Wilhelm wrote: > > Conclusion: you have some (limited) control on the 1/r^3 part, which is purely magnetic for a magnetic antenna and purely electrical for an electrical antenna, but you will have this "1/r^2 coupling" for both a magnetic and an electrical antenna, meaning you can not generally eliminate the coupling to nearby conductors just by using a "dominantly magnetic antenna" or a "dominantly electrical antenna". > ______________________________________________________________ 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 |
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> I was only saying that the near field component can make the total > interaction significantly different. That is not the point here ... whether the antenna is an electric or magnetic radiator, it *will* interact with items in the near field. *Further* the cobweb is an electric radiator just like any other dipole or yagi and will interact with its environment in the same way as any other *reduced size* antenna. Again, the folding may result in some field cancellation in the immediate environment but that is nothing more than a symptom of *reduced efficiency* just like *any other reduced size antenna.* 73, ... Joe, W4TV On 6/1/2013 5:41 PM, David Woolley wrote: > Actually, you have confirmed my point by showing that, in the near > field, magnetic loops and electric dipoles interact very differently, > thus may have rather different EMC behaviour. I was not disputing that > the far field component interacts at short distances. I was only saying > that the near field component can make the total interaction > significantly different. > ______________________________________________________________ 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 |
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