You've got to look at the material to find out if the inductance or resistance at the frequency of interest will dominate. You also might want to figure out how much power is being dissipated in the
Wire rope (aka cable) isn't all that exotic a material. What's the diameter and number of strands? There's several places in L.A. that sell rigging stuff of various kinds. What are the ends like (thi
In the classic phrase: it depends... For yes... it does depend on the physical dimensions of the objects as well as the frequency. Throw in traps and it gets even more exciting.. This is why antenna
At 10:42 AM 12/17/2003 -0600, FireBrick wrote: I'm not affiliated but have had great success, help, and advice from: http://versales.com They will supply cables, thimbles, press fittings, and assembl
At 04:49 PM 12/17/2003 +0000, kb9cry@comcast.net wrote: I would agree 5 radials just won't cut it and your theory of impedance changing during rain is probably right on. Also your planned number of r
At 10:40 PM 12/17/2003 +0000, Rob Atkinson, K5UJ wrote: Y Fresh water (rain) does not have anywhere near the conductivity of salt water. It alone on your radial field should not make a drastic differ
Hard to do, in a practical sense... You'd need a measurement receiver in an airplane, helicopter, balloon etc, because the field strength at "ground level" isn't really what you're interested. Perhap
Someone probably has made this kind of measurement, but, it was probably for ground wave and for 1MHz (i.e. AM Broadcast) and the measurement was made at ground level. There has been a fair amount of
At 05:09 PM 12/18/2003 +0100, Jan Erik Holm wrote: You need no helicopter. In practical sense just measure the ground wave. We are not trying to confirm loobes in the vertcal plane, then you need hel
Interesting point you raise... In the near field, the radials are mostly there to provide a "return path" or image for the current in the vertical. The question would be whether that "image" gets ben
I did some experimenting with NEC on a radial field that is uneven. A radial every 15 degrees (24 in a circle) on one side, and every 30 degrees on the other. Not a fancy model, in free space, just t
Sounds about right... they'd be measuring ground wave (since that's what's of interest for AM broadcast) -- Original Message -- From: "Paul Playford" <w8aef@worldnet.att.net> To: "Jim Lux" <jimlux@ea
Is this actual LMR400 (from Times Microwave, http://www.timesmicrowave.com/) or some knockoff? It's hard to tell, but it's kind of telling that they say "meets LMR400 specifications"... One might won
toss heard RG-8 is a published specification in the public domain. Anyone can make something, call it RG-8, and as long as it meets the published specification, they're perfectly ok to do so. If the
Indeed, I AM quite the cynic, when it comes to the wireless industry, or importers of off-shore illegal knockoffs. I'd be even worse if you were talking about the entertainment industry. Actually, I'
I agree with Joe here... I don't mean to impugn Jefatech.. just their webpage (the single page linked..by the way) seems to imply that they are selling LMR400, but not quite.. And, practically speaki
Outstanding.. and they even responding over the weekend.. I am impressed.. I would caution on a few issues, not that they're relevant to Jefetech. ISO9001 doesn't mean that a product is of good quali
If you're just looking for ballpark (i.e. not suitable for filing with the regulatory officials), recall that aerodynamic loads go as the square of the wind speed. Load is proportional to ( area * sp
This is what surveying is all about. A reasonably competent surveyor could come out and stake out everything you need fairly quickly. You could probably do it yourself, if you had a friend to help ho
At 02:40 PM 12/22/2003 -0600, hasan schiers wrote: In QST sometime in the last 3 or 4 months there was an EXCELLENT article that showed how to put down the most efficient radial system for any given