It will also make a pooling place for water if the conduit does not run downhill away from the house. Not everybody can use conduit. The bend also makes it real hard to add content to it later on, be
In general these problems are very complex, requiring the kind of solutions below, on a very individual basis. Modeling everything, including tower, guys, etc in a vicinity, will allow you do an effe
Sure, you are compensating for a distance in the open with a piece of coax with that has the same velocity factor on the bands in question. It does assume that you are not using 1/4 wave matching sec
If the phase length of the free space horizontal offset (FSHO) is xdeg on 20 then it is 21/14 * xdeg (or 3/2 * xdeg ) on 15, and 28/14 * x (or 2 * xdeg) on 28. If the coax is .66 VF, then the length
See below: That's what I've heard they say. HOWEVER, if you model a pair of C31XR's in EZNEC, to allow element interaction, rather than the abbreviated method used in TA... then... ONLY the 20 meter
To continue on this business of C31XR stacking, I would like to thank Natan Huffman for forwarding some literature, wherein lies the genesis of the 37-40 foot spacing. I have determined much smaller
Would not be 1500 watts into the blocking filter. That would mean that no energy was radiated and all your transmitted power was being channeled (somehow) into the other band's elements. You would ha
Wouldn't it be easier to put a large cap between the bottom of the unun and ground, for DC blocking purposes? One of these 1400 pf, 15 amp caps? --. .-.. 73, Guy Guy Olinger, K2AV k2av@contesting.com
We used Dunestars at N4AF for the CQWW CW. They were between the exciters and the amps, never subjected to the 1.5 kW levels. Some antenna/band combos were on different towers, some combos in use wer
Probably nothing changed on the tower or the feedline from the shack. (How long ago did he measure the first swr readings?) Either the lengths changed a lot in the shack when he added the linear, or
This is the rule I am used to seeing. - - . . . . . . - - . . . . - - . . - . . 73, Guy k2av@contesting.com Apex, NC, USA -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towe
You will need to add some kind of electrical bonding for RF to the design, top and bottom of the tube. Otherwise two metal parts touching one another and subject to rubbing, formation of a diodic con
NOT a good idea to use water pipe as an elevated ground. What you have done with the water pipe is spread the RF through the house. It probably radiates a good deal. Sink a ground rod(s) outside as c
-- "BUZZ SAWS" ABOUND ON HF "The HF buzz saw is dead; long live the HF buzz saw!" That might be the cry from the crowd these days as various buzzing intruders have been showing up with some regulari
A while back I was interested in the same antenna, and inquired among PVRC brethren. I was told to forget it by some number of them, which included one top op who was replacing his Mosley stuff. I wa
A 30% tuner loss is huge and would be dissipating 500W of a 1500 watt input in a closed space. That wouldn't take long to set it on fire internally, and would quickly make it too hot to touch. On the
It will be further helped by a ground screen underneath, if it's 2 feet over dirt. See much discussion on ground screens in the last couple of months. - - . . . . . . - - . . . . - - . . - . . 73, Gu
This seems to be one of those degree of effect things. Model ling of plain (no traps, no bends, no loading, no 4 inch element separations, just aluminum tubing, etc) elements and their combinations h
You HAVE a 34A. Put it up with your dipoles. DON'T use old coax. Pay attention to numerous articles about how to deal with cleaning/preparing old beams, weather-proofing, burying, routing, lightning
Author: Guy Olinger, K2AV" <k2av@contesting.com (Guy Olinger, K2AV)
Date: Fri, 8 Oct 1999 17:31:25 -0400
The values vary considerably. You will have to experiment. When I used an L network in New York for this kind of antenna, the L varied from band to band, and from CW to SSB on 80. I could walk 20 ft