On Sun, Dec 23, 2012 at 8:42 AM, Patrick Greenlee <patric...@windstream.net>wrote:
> Would anyone recommend any changes? > Yes. > > I have a Flex 5000A with twin RCV and ATU sitting adjacent to my tower > computer with Astron switching supply sitting on top of the tower. The > coax runs from the operating position through my wood shop to an outside > wall where it goes outside into a plastic J-box in which there is a static > arrestor with replaceable cartridge wired to a ground rod. From there the > coax goes underground in a PVC conduit to my barn where it is run inside to > a one input -five output remote controlled coax switch and thence up to and > through the peak of the roof to a 1:1 BALUN with coax in and wingnut/studs > out where one side is attached to the metal roof and the other side to the > base of the Hy-Gain Hy-tower 5 band vertical with no radials (metal bld is > counterpoise.) A friend recommended I drive a ground rod to ground the > metal building and I will do that soon. > You should do that to provide a lightning ground. The building probably has sufficient capacitive coupling to ground to make the ground rod unnecessary. > > The Flex is connected to the computer via the Flex provided Firewire cable > (came with ferrites at both ends) but the computer and Flex are not bonded > together and neither is grounded other than their AC plugs having a ground > connection (U-ground) and they are plugged into the same GFCI outlet. The > Cat 5 telephone wire I used for remote control of the 5 position coax > switch runs in the conduit with the coax. > Bond radio to computer. Use ferrites on the 1394 cable. Add a coax current choke at the ground rod and also in the shack. Add a common-mode choke on the CAT-5 switching cable both where it comes out of the ground and where it enters your shack. > We have a 10 station intercom/radio that experiences very mild RFI in some > instances. The satellite TV RCVR and all the TV's distributed around the > house experience no noticeable RFI. We have 12 cordless telephones plus the > two base station phones (two systems) and experience no RFI. > Add common mode chokes to the wiring entering the intercom. > > Any recommended changes. additions,. or deletions? What about adding > another replaceable gas tube cartridge arrestor thingy at the base of the > antenna on the coax side of the BALUN? That is where it should be anyway. > What about shorting one of the unused coax outputs on the 5 position coax > switch shield to center conductor and bonding that to the building so > hopefully a static discharge would not propagate toward the radio > installation via the coax when the coax switch was switched to that > position. This would require the operator to switch the coax switch to that > "Grounding" position when not operating. My thought on this is that it is > better to blow up a 5 position coax switch than a nice Flex 5000A! > All good ideas. Most good coax switches do ground the center conductor when the coax is not selected. This improves isolation as well as providing better static discharge and lightning protection. A good remote switch should do the same thing using the NC contacts on the relays. I bet yours probably does. > > 73 from Patrick AF5CK, standing by for comments and suggestions. > You seem to be well on the right track to me. -- Brian Lloyd, WB6RQN/J79BPL 3191 Western Dr. Cameron Park, CA 95682 br...@lloyd.com +1.767.617.1365 (Dominica) +1.916.877.5067 (USA) _______________________________________________ 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/
