> Once that's done, if you needed more isolation, I'd replace the box with > a metal one. If the sleeve-type choke works well enough, use the plastic > box you have.
I have been continuing my tests with the CAT5 balanced line. The BNC connector, 1.4:1 toroid transformer, and RJ45 were put in a Hammond 1590G cast aluminum box. Then I connected the box to the truck radio. Tuned through the whole AM band and didn't hear any signal, not even a het with the R30CC in USB mode. Nothing. Next I connected the 150' run of CAT5 to the box and terminated the other end in a 100 ohm resistor on a RJ45 jack, no shielding. Very short leads, however. In tuning through the band, much of it was below the noise floor of the R30CC. Locals were down a significant amount from the whip antenna. Semi-locals like some Boston stations and all NYC clears were non-existent. So, the box did help. Kudos to Rick Kunath for the suggestion. I need to order some more BNC jacks and some of the Hammond boxes to make up some more adapter boxes, and cut another length of CAT5. Next trick is to put the RPA-1 preamp at the antenna end to further swamp out the remaining leakage. I'll just run the preamp off a 12V 7AH lead-acid battery such as is used in a computer UPS. That way no wiring needs to go there to supply the power for the preamp. Looks like progress! Once the DX Engineering phaser comes back next month, I'll try again to phase the two loops. However, I will set them up away from any metallic objects. I think the tower in the yard is warping the loop patterns. One other thing I want to try is to roll out some chicken wire over the CAT5 to see if it shields the wire from pickup. The capacitance to ground, plus the inherent loss may just help. Maybe just the 50' closest to the truck. It will be very easy to do an A/B test. Set out the CAT5, do a bandscan with it terminated. Then roll out 50' of chicken wire over the nearest 50' and do another bandscan. Compare notes. If it helps, then do another 50'. It may function just as a series of chokes on the wire itself, using the lossy ground for attenuation. Chicken wire is cheap, so.. Craig Healy Providence, RI _______________________________________________ IRCA mailing list IRCA@hard-core-dx.com 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: irca@hard-core-dx.com