Bob:
Without going into all the details: 1. The wall plate (aluminum) is attached to a #4 copper wire that is connected to a ground rod just outside the shack. This wire then extends underground to and circles the tower and continues underground to a vertical antenna. There are five additional ground rods (all mechanically bonded to the #4 wire) around the tower with three of them attaching directly to the tower legs and additional ground rod (also mechanically bonded to the #4 wire) at the base of the vertical antenna. 2. No. 3. Ground Floor. 4. Short, a few feet. See #1. From: k8...@aol.com [mailto:k8...@aol.com] Sent: Thursday, December 27, 2012 5:08 PM To: ke5...@tx.rr.com; kb6...@yahoo.com; flexradio@flex-radio.biz; flexe...@flex-radio.biz Subject: Re: [Flexradio] [FlexEdge] Product Decision Everett, Below you stated; "5. Star grounded (with 1" wide braided cables) my 5000A, computer case, amplifier and tuner to the wall plate which itself is an extension of the entire systems grounding system." Questions: 1. What kind of grounding is system is your wall plate connected to? 2. Is this "wall plate" your electrical duplex outlet "wall plat"e? 3. Is your ham shack in the basement, ground floor or second floor? 4. How long is the connection from your "wall plate" to the earth ground? The house hold electrical system ground is not an effective RF ground system. Depending on the location of your ham shack and size of your house your house hold ground (cold water pipe or a ground rod at the electrical power input to the house) may be 60 or so feet away from ground. If that's the case it may be resonate 1/2 wave length at 40 meters and would put your rig at the worst possible place for RF ingress. If the above is the case, a set of 1/4 wave counterpoise wires for each band you want to operate, connected to the star ground point and end of the wire connected to nothing. If this is not possible, recommend an artificial ground system. Bob K8MLM In a message dated 12/27/2012 12:32:31 P.M. Eastern Standard Time, ke5...@tx.rr.com writes: Robert: I have two baluns from Balun Designs one of which is the 1115DU. Both are very well made, heavy duty items. I have not used or seen the MFJ device, so I have no comment on it. My operating location is fairly close to my antennas which caused a number of RFI issues. The steps I took were: 1. Installed ferrite beads on most of the interconnecting cables in the shack. 2. Installation of current baluns at the bases of the antennas. 3. Replaced a "stock" (read cheap) firewire cable with a Granite firewire cable. 4. Replaced my (largely) plastic computer case with a metal one. 5. Star grounded (with 1" wide braided cables) my 5000A, computer case, amplifier and tuner to the wall plate which itself is an extension of the entire systems grounding system. Hope this helps. Everett KE5MMT -----Original Message----- From: Flexedge [mailto:flexedge-boun...@flex-radio.biz] On Behalf Of Robert Costa Sent: Thursday, December 27, 2012 10:46 AM To: Flex Radio List; Flexedge Subject: [FlexEdge] Product Decision All, As many of you have read and are probably tired of hearing, I am chasing down my RF ingress issues into my Flex 5000a, which seem to be even acting up on 40 meters and above now. As part of my potential solution, I will be purchasing a isolation choke. I had decided on a product, when a friend of mine pointed to another product that is almost 1/3 the cost. Now I do believe in the old adage that you get what you pay for. I was on the phone with Bob from Balun Designs. He suggested a dual core 1115DU. The cost is $79.00 plus shipping. The item has great characteristics as far as SWR, line loss and choking impedance from 160-10 meters. My friend in a QSO last night suggested the MFJ-915. This item is only 29.99. It consists of a bunch of ferrite beads. As it is MFJ, I do not expect them to publish any specifications or sweeps from a spectrum analyzer. Hs anyone dealt with either one of these products or both? Can you give me your honest opinion on the performance versus cost analysis? Thank you and 73 Robert KB6QXM _______________________________________________ Flexedge mailing list flexe...@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software innovation and other technical SDR topics. _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/ _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
