Bud, The "end of the cable" is not significant. Lightning does not respect any particular "end of the cable".
The situation extends well beyond the RS-232 connection to the K3. It includes everything in your hamshack. The real answer is that in the event of a surge, everything in the shack should always be at the same potential - even if that potential is many kilovolts above normal ground potential (I do not exaggerate) - but achieving that requires providing some protective measures. If you have done nothing in your hamshack installation to handle lightning surges. AND you in a high lightning incidence area, the best protection is to disconnect everything when not in use - do that until you have a good surge protection scheme installed.. Of course, that is really not always practical - so if you wish to protect your K3 correctly (along with all the other equipment in your hamshack), install some good lightning protection - single ground point entry point for ALL lines coming into the hamshack - NO exceptions - ethernet, telco, antennas, rotator, control lines, and yes even the AC mains entry to the hamshack should enter through a single panel employing MOV or other protection devices present at that panel for each and every line - this is the single most important point of lightning protection. Look at all the equipment in your hamshack area, and consider everything within a 4 foot radius from each piece of equipment as something which should be within your "area of protection" - all lines connecting to those pieces of equipment should come through this "grounding window". If you can touch any piece of equipment while at your operating position, it should be included in the protected equipment region. That is a minimum - I would also recommend that you also have a perimeter ground wire around your house, and from each tower or mast (and vertical antenna), you have a good surge dissipating ground system installed consisting of at least 4 ground radials at least 30 feet long. These ground wires should be #6 or larger wire and be connected to DRIVEN ground rods at intervals not exceeding 2 times the length of the ground rods. The principle is to allow the surge to dissipate into "mother earth" as easily as possible. Take a look at the information n the 3 part series on Lightning Protection that was pubilshed in QST in 2002?. Go to the ARRL website and do a site serach on Lightning Protection. The 3 part articles by Ron Block are my personal "bible" for lightning protections. One important note - any grounding system (unless more than 150 feet from the house) must be connected to the house Electrical Utility ground wire - NEC requires it - ignore this fact at your own peril - failure to do that can destroy equipment and place you and your family in danger should a lightning surge occur (consider fire hazards). 73, Don W3FPR Bud Morin wrote: > I hope this isn't true. Which end of the cable? For over a year I've > never disconnected it. I'm too old to reach around, under, or over the > shelves to try disconnecting and all that is involved in that. > > On 7/19/2010 6:08 AM, Pete Smith wrote: > >> Elecraft advised >> me always to disconnect any cable from the RS-232 port on my K3 when not >> in use, from which I inferred fragility. >> > > 73, > Bud, K9ZT > > ______________________________________________________________ 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
