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Michael Coslo wrote:
bb wrote: Mike Coslo wrote: bb wrote: Mike Coslo wrote: Now lets talk about antennas. It isn't likely that we will have single antennas at any station, save for the resurrection of the old general purpose dipole fed with ladder line, run through a tuner. Or a random wire fed against ground. That's one that olde tyme hammes will recognize! I suppose the Steppir antennas could work if you have enough coin. The method proposed by Jim will not accommodate the tricks we use now to provide an acceptable match as the major HF bands will not be harmonically related. ??? There are solutions to both the rig and antenna problems. But they aren't as easy as some would have us believe. More important, unless a considerable number of hams equip themselves to use the new bands, they aren't much help. And does propagation varies that much between most of the bands we have now? I don't think so. It was argued that the difference in propagation between 80 and 40 could be great enough that access to a band near 60 was needed. And we almost got a full band there, except that NTIA reversed its support after 9/11. But the jump from 80 to 40 is a doubling of frequency. From 40 to 20 is a doubling also, but we have 30 meters in between. Would a band at, say, 8.5 MHz be that much different from 7 and 10 MHz? Or would we be better off with more worldwide-exclusive-amateur-kHz on 40 and 30? Trap dipoles don't have to be on bands that are harmonically related. I've built and used trap dipoles. The more bands you add, the more complex the adjustment procedure becomes. Does anyone else here have experience building trap dipoles from scratch? Perhaps we should go back to what Jim posted with his original question: Jim's quote * Right now we have 9 HF/MF bands, plus some spot frequencies in * the "60 meter" region. * * Suppose that at some point we hams had the choice of either: * * 1) New, very narrow bands elsewhere in the HF/MF spectrum (say, 2.5 to * 2.6 MHz, 6.0 to 6.1 MHz, etc.. * * or * * 2) Widening of existing bands and/or change to worldwide amateur. Such * as 7.0-7.4 becomes worldwide exclusive amateur, 10.1 to 10.2 does the * same, 14.0 to 14.4 (which the band used to be), etc. * * Which would be preferable, if we wound up with the same number of kHz * overall? End Jim's quote. Under Jim's scenario, we would be adding several bands. Under one of my scenarios, anyway. That trap dipole would be interesting indeed! Likely mostly traps. Maybe I'll try to design one. Jim will have to give me the specific frequencies that will be added in his scenario. Let's say the following additions/changes were made: A new band 50 kHz wide at 2.7 MHz A new band 50 kHz wide at 8.6 MHz A new band 50 kHz wide at 11.9 MHz A new band 50 kHz wide at 16.0 MHz A new band 50 kHz wide at 19.6 MHz A new band 50 kHz wide at 23.2 MHz A new band 50 kHz wide at 26.4 MHz or 5.1 to 5.2 MHz instead of 5 channels 7.0 to 7.3 worldwide exclusive amatuer 10.1 to 10.2 worldwide exclusive amateur 18.05 to 18.2 worldwide exclusive amateur And trsp dipoles are not a very universal answer. In my situation I would have to make a loaded trapped dipole for 80 meters and to cover other bands. Now *that* would be a hoot! And quite heavy. Some folks can't even get a random wire up and radiating HF RF.... 73 de Jim, N2EY |
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