> > "Dallas Lankford uses ordinary AC twin lead or speaker wire. He says it > > works better than coax. With a balun, of course." > > I use a coax with a 100' run NE of the ewe balun. Would using AC twin > lead or speaker wire affect the directional pickup of the ewe? Would > noise level increase The above method would be less expensive than > buying coax and the connectors. Much easier to replace when my lab > chews on a the coax cable.
I suppose the best way to test it is to disconnect the far end. Either short the center to the shield, or (better) terminate it on a shielded 50 ohm dunny antenna. In my tests, both Radio Shack RG-58 and good quality RG6 TV lead in had a significant amount of undesired signal. For example, with 150 feet of RG-58 rolled out in my yard and terminated in a shielded dummy load, I still could hear all of my normal locals at good level. WSKO-790 was at S9+20 for example. No type of grounding made the least bit of change. If you have significant signal, then it's worth a shot to try replacing it with a balanced line. Coincidentally, I just finished testing a 150' run of CAT5 ethernet cable this afternoon. I made a 100 ohm termination for the far end, and a 100 ohm to 50 ohm balun. Leakage signals dropped a significant amount. I could hear the strongest locals, but not much else. A real improvement. I took one of my 30" copper tube loop antennas and wound a second pickup on the toroid. I used six turns connected to a standard RJ-45 jack. Plugged in the ethernet, and had nice signal levels on the radio. Turning the loop did show significant nulling, unlike when I tried to use it with the RG-58 coax. It's only a short test, but results are encouraging. Parts: Home Depot CAT5 indoor/outdoor cable bought in a 500' carton size. Used a 150' run with nornmal RJ-45 ethernet connectors on the ends. Homemade balun: BNC connector to 8 turns on a FT-87-J toroid core. 12 turns punched down to an RJ-45 ethernet jack. I will experiment with different turns eventually. That ratio was just a guess pulled out of thin air. Antenna end is the six turns through the FT-240-75 toroid which is on the 30" copper tube loop. I only used the blue/blue-white pair in the cable. The other three pairs were left unconnected. Further tests will involve grounding one or more pairs and seeing if grounds at either end make any reduction in the input leakage signal. Craig Healy Providence, RI _______________________________________________ IRCA mailing list [email protected] http://montreal.kotalampi.com/mailman/listinfo/irca Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers For more information: http://www.ircaonline.org To Post a message: [email protected]
