Thanks Don, and all who contributed to help him. Yours has been an interesting story and it was educational to watch it unfold here. I bet the CQ or QST would eat up a story like that if it was well documented and turned out as well as yours.
Regards, Ken Alexander VE3HLS On 23/10/2011 9:13 AM, [email protected] wrote: > First, let me say thank you to everyone on the list who has replied via > the list or directly. The help has been fantastic and has increased my > general knowledge as well as helping me with the problem. > > Althought I have pointed to the start of the problem with the > installation of the Loop and the install of the propane tank and > possible crushed coax, I now believe that I have always had some RF > issues but it was brought to my attention by the Loop being real bad and > then I was highly sensitive to the whole system. > > First I had made a significant error in the basic grounding of my shack. > This error I will call the green wire mistake. What I had done was add > the chassis ground of all my 12v devices and tuner to the green wire > ground of the house electrical system. This is in fact a signficant > error and has been corrected. What I have learned that there is a > difference for a saftey ground for lightening protection and so on and > it has nothing to do with an RF ground. So green wire error fixed, long > term a total revamp of the system for a safety ground. > > Second I did a lot of checking of the coax yesterday. Checked it with > nothing attached, checked it with a dummy load, used functions of my MFJ > 259b that I did not even know existed. Basically the coax checks out > fine, but I still have RF. The coax at this point in time is no longer > buried, I completely unearthed it. > > At this point in time I put a choke at the antenna feed up in the air > with 31 mix ferrites and no improvement. So if the problem is at the > antenna feed this should have fixed it. I remove my lightening arrestor > from the system just to check it out no change. So I pull the choke > down. > > Next I put a choke right at the antenna out the same choke that I had > put on the antenna feed point. Wow big improvement plus I added more > snap on 31 ferrites directly on the coax. So I have a choke in the > shack and now I can go full power. So having the choke at the feed > into the antenna tuner has a dramatic effect. > > Now I am thinking ok I will burry the coax again, easy to do in the soft > grass plus I want to see if the problem turns on again as I have changed > the system with the coax laying on the ground and the outside is dry not > directly coupled to the set ground. After the burry RF is bad real bad. > So coax is now on laying on the ground again unearthed and the system > again functions, points again to bad coax. > > I am now convenced that this is it so I turn on the shack PC to get some > more information and so on. Plus I am talking to some other hams on > what I have found. As the PC boots up the RF is back and it is strong. > Holy Sxxt Batman, now what. So I ponder this for a moment, since I > removed my geen wire error the PC is no longer connected to the K3 than > thru the rs232 so I am assuming Pin1 problem. I make a ground wire from > the chassis of the PC to the center of the grounding point (grounding > star as it is referred to) and fixed. So I take a critical look at the > PC installation and the coax runs right next to the PC. So I disconnect > everything and move the PC to the other side of the desk to get it as > far away from the coax as I can plus this eleminates short jumper cables > for the mouse and so on. So other than a brief instant when the PC > boots up and it is a very specfic part of the boot cycle there is no RF. > > So in a nutshell > > 1) fixed green wire problem > 2) unearthed coax and it is laying on the ground on the top of the grass > 3) build choke with 31 mix at antenna out on the tuner > 4) moved PC > > I am on the air. > > To do when the order shows up from UPS. > > Install new coax, I assume the one I have is not happy anymore and test > the system to see if I can remove the choke at the tuner. > > From my perspective I am on the air, but I do not have a robust > installation being on the 2nd floor. I probally can survive this winter > this way with the simple antenna shield grounding outside as I did last > winter as there is no lightning normally. However, I have to determine > the best way to redo the installation and am considering moving the > shack to the basement where then it will be signficantly eaiser to have > the shack properly grounded for safety and then bonded. > > Again thanks for the help, as I am on the air but not convinced that I > have it fully cured. So there may be more questions in the future when > I find stuff starts to not work again. > > ~73 > Don > KD8NNU > > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
