But I keep coming back to this: almost every device connected to the power supply has V- connected to ground internally. So if you have, say, a keyer and a transceiver running off the same supply, won’t some of the transceiver’s current flow through the V- line to the keyer, to the case of the keyer via the internal connection, to the station bonding, to the transceiver case and thence to the transceiver V- input?
In short, don’t the accessories fed from the same PS as the transceiver do exactly the same thing as the notorious black wire in the Astron? Vic 4X6GP > On 16 Apr 2018, at 23:50, Jim Brown <j...@audiosystemsgroup.com> wrote: > > Joe is right and George is WRONG. V- is NOT GROUND, it is the return for DC > power. Bonding V- to ground is a BAD idea -- that's why virtually all > pro-grade power supplies are built either without the bond or so that the > bond can easily be removed. > > As to those who were confused by my advice -- I thought it was pretty plain. > > Quite a few posts back, I posted a link to a detailed discussion of this on > my website. I published this around 2010-12. I urge those who are confused to > study it. > > http://k9yc.com/PowerSupplyBondingAndAudioDistortion.pdf > > My detailed advice on station grounding and bonding is the link below. Much > of it has been incorporated in Ward Silver's recent ARRL book on the topic, > and is referenced in the book. You can buy the book from ARRL, while the pdf > on my website is free. :) Joe and Don are right on in their understanding of > the NEC, the fundamentals of which I have been paid to teach to audio/video > professionals in workshops at conventions. > > http://k9yc.com/GroundingAndAudio.pdf > > 73, Jim K9YC > >> On 4/16/2018 7:06 AM, Joe Subich, W4TV wrote: >> >> On 2018-04-16 9:28 AM, George Danner wrote: >> > Re-Connect it! >> >> DON'T CONNECT THAT WIRE BETWEEN V- AND CHASSIS CASE! >> >> Unless you have a substantial *EXTERNAL GROUND CONNECTION* >> between your station ground and the electrical system ground >> rod, that connection between V- and chassis will bridge the >> power system "safety" ground and the station grounding and >> put your delicate and expensive equipment between two "grounds" >> that can separate by many hundreds of volts in a lightning >> event (or equipment failure). >> >> > We even used ring grounds around studio & transmitter building with >> > ground rods every 10' all cad-welded. >> >> That is proper grounding and bonds all entry points together *OUTSIDE* >> the building to prevent grounds from separating. It creates a common >> "island" for everything inside the building. However, for the majority >> of amateur stations which fail to properly bond the shields of all of >> the coaxial cables entering the shack to the electrical system ground >> *at the meter*, there is no "island" ... more like an isthmus across >> the equipment. >> >> 73, >> >> ... Joe, W4TV >> >> >>> On 2018-04-16 9:28 AM, George Danner wrote: >>> Re-Connect it! >>> >>>> From a broadcaster (AM,FM & TV) was in South Florida (lightning capital of >>> North America). >>> >>> The more massive the common (ground, bonding, whatever term you use) for >>> the connection between equipment and the power company ground connection >>> the better. >>> We even used ring grounds around studio & transmitter building with ground >>> rods every 10' all cad-welded. This is probably over kill for a ham >>> station; but think as massive as you can. >>> Towers at 500' or above had 2 ring grounds and lots of ground rods. >>> >>> The common for equipment interconnection is for safety first and the >>> reduction of voltage drops on the common lines that can transfer from one >>> piece of equipment to another (us old timers use the term ground loop - not >>> PC any more). >>> >>> 73 George AI4VZ >>> >>> -----Original Message----- From: Charlie T >>> >>> "This greatly increases the chances for damages to station equipment and >>> all other electronic equipment in the household in event of a lightning >>> event." >>> >>> What is, disconnecting the wire or leaving it in place? >>> Your comment can be taken both ways. >>> >>> 73, Charlie k3ICH >>> >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to li...@subich.com >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to j...@audiosystemsgroup.com >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k2vco....@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
