Topband: radial wire alternative
This had worked well for radials in the desert of New Mexico both on the ground and elevated American FarmWorks Poly Wire, 1320 ft. at Tractor Supply Co. The conductors are stainless steel and havr about the same ohmic resistance as galvanized wire _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Radial Wire
Joel W5ZN wrote: ... low cost radial wire options got me thinking about WD1A. Anyone have any experience with it as radial wire?? There are two wires that should pull apart easily ... I use WD1A wire mostly for (single direction) Beverages, but also as radials at the ends of those antennas. In my experience it is excellent for both applications BUT only if the two wires remain joined. If they are pulled apart they seem to be self tangling! I think that the wire is actually a very clever design - the two wires appear to have opposite twists - so it lays very flat and straight. (I know this is not the subject of the posts, but I would emphasise that WD1A is horrible for bi-directional Beverages as the loss is excessive in the transmission line mode.) 73 Roger VE3ZI _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: OT - disconnecting coax and rotor/control cable
Don't know where best to post this and I respect the knowledge base here so I'll ask with the OT in the subject line. I'm getting to the point I want to do less effort and still do things right. I had lightning damage to a K3 and don't want to do that again. What enters the house are: - RX antenna controller cables One with 5 wires, one with 6. - Antenna rotor cable 6 wires. - The remote coax switch 7 wires. - Two coax going to the amplifiers. - Two RG-6 coax going to the Rx antennas. I would also like to separate the 120 V strips at the same time What I would like to do... is have one or two switches to flip that will allow disconnect of all of this. As it is now, I have to unscrew each coax each time I close the shack and re-attach the next time I'm in the shack. I made molex connectors for the Rx controller cables, have not yet done that with the rotor cable nor the remote coax cable. I unplug the power to the terminal strips I was thinking of perhaps using relays (I have a lot of SS relays but don't think they would be usable in this endeavor. Maybe relays like in the old SB-220 where there were many individual relays activated at the same time, would work for control/rotor cables. But I wonder if the air gap in such a relay would be sufficient to be a barrier come another lightning issue. I have several vacuum & heavy contact air gap relays that could do the job for the coax. I also have some substantial relays I could use for the power cords involved. If I were to have all this in one enclosure, it would be nice to get up, flip a few switches and walk away knowing my station is truly disconnected. At this point I have time to do anything, and I like making things, but only if it's worth the time. Thoughts? 73, Gary KA1J _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Radial wire
I have maybe 45 radials, some of them WD-1A. I bought over a mile of CAT cable and used it for antennas and radials, silver-soldering the wires together & attaching them to the plate or coax with ring terminals. They worked fine for radials, show no wear after around 8 years. I used WD-1A for a couple bi-directional Beverages and found the salt marsh with tall phragmites dry & blowing in the wind set up so much static that it was noisier than my then INV-L. At that time I went to HI-Z antennas and never looked back. I used the WD-1A for new radials, cutting it into 130' sections & silver-soldering this as well. The WD-1A is only 5 or so years old as radials but I see zero issues in an acidic salt marsh thus far. However... As to splitting the WD-1A, don't try it, it's a waste of time. You have to carefully get the wire split so as to not expose the stainless inside and then once you finally do get the two halves apart and pull them apart, you have a pair of snake-like helixes. The abrupt bend as they separate makes the helix and it will not lay flat. If you were to bury it, it'd probably be OK. I use WD-1A for antenna wire now, bought about 2 miles of it for the future & will likely use it in its natural paired state for radials when I relocate. My 2 pence. 73, Gary KA1J > I like to buy copper wire when I find a good deal surplus or otherwise > and horde it up whenever I need it. > > In following this thread and seeing some folks seeking low cost radial > wire options got me thinking about WD1A. Anyone have any experience > with it as radial wire?? There are two wires that should pull apart > easily and give you a "2 for 1" deal. > > Anywho, just curious if anyone has any experience using it for > radials? > > 73 Joel W5ZN > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Radial wire
Rob, Not barbed wire, but electric fence wire. This wire stays good for decades. Look at the horse and cattle farms around you. It has the same conductivity as your galvanized steel tower. Nor does anyone consider making a tower out of copper or copper clad steel.☺ A radial system of 60 1/4 wave of #10 copper cost 50 times what the electric fence wire costs. Herb, KV4FZ On Thu, Sep 6, 2018 at 1:21 PM Rob Atkinson wrote: > Oh man, any time this topic comes up anywhere the guys come out with > all kinds of suggestions for wire that won't last like galvanized > steel and electric fence wire. Nix nix nix...if you want a permanent > ground system go with copper, insulated or not. Stranded doesn't lie > down as well; you want soft drawn copper sold. Stranded wants to > spring up and stay coiled, especially if it is hard drawn antenna > wire. Use that for antennas. Copper clad steel can be hard to work > with too unless you have a spool on a radial plow and are laying it > into a slit a few inches deep with a tractor. > > But if the installation only has to last a few months then use the > barb wire, etc. > > 73 > Rob > K5UJ > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Radial wire
Well, electric fence wire comes in various levels of galvanizing. The cheap stuff such as RedBrand is class 1 and is galvanized to 0.28 oz of zinc per square foot. Bekaert Wire 17ga which is 0.80 oz per sq. ft. and is also available from Tractor Supply. I've never seen any electric fence wire that was better than that. It goes for the same price as RedBrand, but typically has to be ordered...at least that's the story from my Tractor Supply. So, $29.99 for 1/2 mile. RedBrand is made in the USA and Bekaert is made in Belgium. That exhausts my info on electric fence wire! 8*) 73, Ken - K4XL On Thu, Sep 6, 2018 at 1:47 PM, Mike Waters wrote: > I don't know which brand is best, but I think the thickness of the > galvanizing varies. (W8JI said that most "galvanized" steel electric fence > wire is actually cadmium plated, and not zinc). > > I have a Beverage made from 17 gauge plated steel electric fence wire > that's been up roughly 8 years. The plating is gone from much of it, and > signal levels are really down now because of that due to paramagnetic > losses. In contact with moist soil, I would not expect it to last as long. > > Where is plated steel electric fence wire available with a good thick > plating? > > 73, Mike > www.w0btu.com > > > On Wed, Sep 5, 2018, 1:22 PM Kenneth Grimm wrote: > >> If you have a Tractor Supply store near you, the price for 1/4 mile of 17 >> ga. galvanized electric fence wire is $14.99. You can get 1/2 mile roll >> for $29.99. Just how long it will last will vary depending on your soil. >> However, at that price it is worth a try. >> >> 73, >> Ken - K4XL >> > -- Ken - K4XL BoatAnchor Manual Archive BAMA - http://bama.edebris.com _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Radial wire
I don't know which brand is best, but I think the thickness of the galvanizing varies. (W8JI said that most "galvanized" steel electric fence wire is actually cadmium plated, and not zinc). I have a Beverage made from 17 gauge plated steel electric fence wire that's been up roughly 8 years. The plating is gone from much of it, and signal levels are really down now because of that due to paramagnetic losses. In contact with moist soil, I would not expect it to last as long. Where is plated steel electric fence wire available with a good thick plating? 73, Mike www.w0btu.com On Wed, Sep 5, 2018, 1:22 PM Kenneth Grimm wrote: > If you have a Tractor Supply store near you, the price for 1/4 mile of 17 > ga. galvanized electric fence wire is $14.99. You can get 1/2 mile roll > for $29.99. Just how long it will last will vary depending on your soil. > However, at that price it is worth a try. > > 73, > Ken - K4XL > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Private thanks to you on your posting
Sat Sep 1 21:21:26 EDT 2018 Bryon Paul Veal NØAH bryonveal at msn.com wrote: > I think the problem is due to limited high Q antennas on top band, every one > is > more concerned about 30Khz of usable DX bandwidth. > I find a lot of topband and is fully underutilized, much like 80M. We must remember that not all Top Band operators are weak-signal CW DXer enthusiasts or contesters, or FT8 operators. Some of us enjoy operating between 1800 and 1815 or so, and 1840-2000. We ragchew and participate in other types of operating activities with foreign and domestic stations using AM, SSB, CW and all other authorised modes. I recall starting a thread a few years ago when the FCC was proposing to upgrade amateur status on 1900-2000 from secondary/ Radiolocation primary, to full amateur primary from 1800 to 2000, urging everyone to submit comments to the FCC in support of this proposal. I was surprised at the lack of interest and support. Fortunately, the FCC proceeded with the proposed change and we now enjoy primary status across the entire band. Even those interested solely in DXing in the so-called "window" should have enthusiastically supported this proposal, since if Radiolocation had remained primary in the top half of the band, eventually someone might have developed some kind of technology that qualified to the FCC as "radiolocation" and possibly crowded amateurs out of the top end of the band. That would have meant more congestion in what we had left, including the frequencies used for weak-signal DX work. Don k4kyv _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Edge-wound inductors vs round stock (was Air Wound Coil)
Sat Sep 1 21:21:26 EDT 2018 Mike www.w0btu.com wrote: > It may very well be true that tank coils made from round copper have some > slight advantages over edge-wound. But after all is said and done, does > this really make a great deal of difference? :-) > I have an edge-wound roller inductor in my homebrew amplifier. > http://www.w0btu.com/833C_linear_amplifier.html > It's reliable, doesn't arc, and doesn't get warm. Isn't that what's really > important? I recently ran across this discussion on another radio forum, claiming that edge wound is inferior in terms of Q to round wire. It was said that on a flat strip, the current tends to crowd to the two edges for the same reasons that cause skin effect, thereby wasting much of the copper. Round wires would be less prone to this "crowding effect" because they have no edges. I checked out a few on-line sites, but they quickly get bogged down in long series of long, tedious mathematical equations, and I was not able to come to any clear conclusions. Some suggest that the subject is not well understood, even suggesting Terman's textbook is wrong, or that the effect is negligible if the radius of curvature at the edges of the strip is much greater than the skin depth. The skin-effect proposition makes some sense, although I had never thought of this. The closest I could come to a conclusion from the texts is in regard to the "proximity effect" of closely spaced parallel round conductors, in which the rf current density in each conductor crowds in the direction away from the adjacent conductor. The rectangular conductor could be thought of as approximating a large number of closely-spaced round conductors, so the current density would tend to crowd towards the edges of the conductor. I would like to see/hear some opinions on the subject. I can understand that primary advantage of edge-wound would be for mechanical reasons, for example for a rotary inductor where an effective sliding contact is more difficult with round wire. Slip-on coil clips like the ones EF Johnson used to make are designed to work with edge-wound coils. I would add that the spacing between turns with edge-wound can be decrease compared to the same amount of copper in round stock, thus increasing the number of turns per inch with edge-wound, resulting in more rigidity for a given thickness of conductor. Most broadcast transmitters, phasors and ATU units use edge-wound stock, so there must be a good reason. I threw together a prototype for the matching unit for my 160m vertical, using some badly corroded round-wire coil stock from the junkbox, with deteriorated plastic supporting strips. Once the final design of the coils was determined by trial-and-error, I built a permanent version, using like-new silver-plated edgewound coil stock, with the same coil diameter and turns spacing. I had anticipated slightly better efficiency with the final version, but as it turned out, the prototype and final version performed equally well, neither one any better or any worse than the other. With the same DC input to the final, the rf ammeter reading at the base of the vertical was exactly the same with either set of matching coils. Don k4kyv _ Topband Reflector Archives - http://www.contesting.com/_topband
