Hi TT'ers, A few years ago I bought a used Butternut HF-6V vertical to use as a secondary antenna. it came with the 160 meter kit, which is a large coil and ceramic caps that mounts at the base. I'd
Yeah, it'll work better as an inverted L than a base loaded vertical at that height... but you'll get a fair bit of high angle horizontally polarized radiation from the "top loading wire" ... not ne
Hi Steve.. Take a look towards the bottom of this page.. http://www.iol.ie/~bravo/80&40mVertic.htm 73 John EI7BA _______________________________________________ ______________________________________
My understanding is that use of the 160m loading coil for the HF-6V limits the power to 500w on 160m. Q: What if the 160m coil is left off, and 4 slolping top hat wires were attached to the top of th
I'd believe that. The voltage across the coil will tend to be pretty fierce. 500W seems to give about 7600V across the coil. Full legal limit would be 13kV. Commonly done and generally a decent way t
Straight out gives the highest radiation resistance, but you still get an overall radiation resistance benefit from sloping top-hat wires on a short radiator. I've had good luck with 20 foot long top
"Somewhere I have the modeling data which shows a modest improvement in radiation resistance when the top-hat wire is horizontal (as compared to sloping), but it's not a make or break difference. " I
Yes, I get similar results, Dan. The 60ft top hat wires sloping down at 30 degrees (relative to horizontal) are only about 1dB better than the base loaded 34' vertical assuming that Q=200 and a groun
4nec2 can probably do the optimization. If you can write algebraic equations for the parameters in a NEC description in terms of a few symbols, it can optimize.. For instance, I've done a bunch of mo
If the top loading wires have to slope down due to a lack of tall supports, it makes sense to use as many wires as possible, so that each one can be shorter (for the same resonant frequency) and thus
Yeah, that sound like what is needed. Start the optimizer, go have lunch, and then come back to see where to saw the aluminum tubing :-) 73, Mike W4EF................ ________________________________
I agree, Terry. If aesthetics aren't a big issue, I'd put as much surface area of metal up there as I could. In that vein, larger diameter wire is helpful as well. For what it may be worth, I have fo
...there is a company in Canada that produces a 50ft helical center loaded antenna for use on ships and for Public Safety AM LP stations. Arlington County OEM, VA installed one of this self-supportin
Something along those lines... I thought about this a bit yesterday. 4nec2 can alter physical parameters (including the value of the loading inductor), but I'm not sure how to set it up to get what y
I think you'll also want to optimize for minimum feedpoint reactance in order to force the loading inductor to a realistic value. Otherwise, depending on how sensitive your excitation source is to mi
4nec2 can do this without too much trouble. One of the options is to optimize for minimum mag(X) (i.e. drive to resonance, irrespective of mag(Z)) OK if the inductor is modeled as a fixed physical le
I haven't seen any more follow-up regarding optimization of this configuration, but I'll throw in the results of my modeling in EZNEC (NEC-2 engine). I used the parameters discussed, and varied the l