Re: Topband: Soldering in the wild!
Thanks to everyone who offered a suggestion about soldering in the wild! I managed to run an extension cord out to one failed section of 450 ohm ladder line and fixed it with my trusty old weller gun. However, I discovered two additional sections on the same antenna that are well beyond the length of all my extension cords combined. I think I'll see what one of the Weller or Ultratorches will do for me. I may also pick up a few split bolts for quick and easy repairs if I can find a reasonably priced source. Locally, they are pretty expensive. Ebay may provide better hunting. Once again, thanks for all the suggestions. 73, -- Ken - K4XL BoatAnchor Manual Archive BAMA - http://bama.edebris.com ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Soldering in the wild
Hello All Most of my 'soldering in the wild' has used a small gas-fired torch (a BIC lighter works well) but I have often used nothing more than a strike-anywhere match. Try it - you will be pleasantly surprised ! I wrap the knife-scraped-clean-wires together and then wind a length of solder into the spiral-gap between each turn and apply the heat. Solders every time when there is no wind. I have also used a candle to provide the 'heat'. Years ago at the Slate Peak fire-lookout in WA-State I repaired the light-meter on an old Super-8 camera that suddenly quit working. I had to dis-assemble the camera with my pocket-knife to expose the light-meter cell and found the broken wire. My 'field' soldering iron was a short piece of solid copper bus-wire from the lightening grounding system I found laying on the ground. I heated and tinned it using the propane fired stove in the LO and pressed it on the cell/wire interface. I always kept a short piece of solder rolled-up in my wallet for such situations. The fire-LO lady was very impressed. 73 Dick/w7wkr CN98pi ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Soldering in the wild!
Small C-taps are available that can be used as splices. Even the small ones are usually for large(ish) (by antenna standards) wire, generally 8+ gauge. There may be smaller ones available. Common manufacturers are T&B, Burndy, and Panduit. The smaller C-taps can be installed with a mechanical (non-hydraulic) crimp tool that is around $100. The tool I have appears to be the T&B "ERG2008" now (although mine is not that exact model). These tools are commonly used in the telcom industry to install compression lugs on 6-4 gauge DC power conductors, but they can handle the small-size C taps too. Burndy makes some taps that have the no-ox pre-applied, although I've only ever seen those for 4 gauge and larger conductors (they are used primarily for ground systems in places where cadweld can't be used). -Bill > That said, split bolts are NOT in common use for load carrying connections > and haven't been for some 40+ years. Most all connections, tension and > non-tension, are done with compression splices where the conductor > grooves/holes are prefilled with oxide inhibitor. Hand operated hydraulic > or compressed air/gas driven compression tools, with the correct die for > the > type/size of connector, are utilized for making splices which will > withstand > mechanical and electrical loads at their rated values for the life of the > conductor. The compression tools are quite expensive, but the connectors > themselves are relatively inexpensive. > > Mis dos centavos. > > Milt, N5IA > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Soldering in the wild!
-Original Message- From: kaz Sent: Monday, August 06, 2012 9:20 AM To: topband@contesting.com Subject: Topband: Soldering in the wild! ---SNIP--- Split bolts can also be found in stainless varieties in case the materials being joined might not like touching copper. Not a great selection of sizes though. ---SNIP--- 73 de w4kaz - Milt, N5IA, commented: Within the electric power distribution industry, where conductors of two different metals (typically copper and aluminum) are to be connected together with a "split-bolt" device, the connector is made of plated copper AND the two conductors are separated in the split by a similar plated divider. All copper split-bolt connectors are still obtainable, but are NOT the norm. Personally, I have never seen a stainless variety. I know of no reason why stainless would be required. That said, split bolts are NOT in common use for load carrying connections and haven't been for some 40+ years. Most all connections, tension and non-tension, are done with compression splices where the conductor grooves/holes are prefilled with oxide inhibitor. Hand operated hydraulic or compressed air/gas driven compression tools, with the correct die for the type/size of connector, are utilized for making splices which will withstand mechanical and electrical loads at their rated values for the life of the conductor. The compression tools are quite expensive, but the connectors themselves are relatively inexpensive. Mis dos centavos. Milt, N5IA ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Soldering in the wild!
FWIW, in a pinch I have used an ordinary butane cig lighter to solder small joints. Not ideal, but possible[if its not too windy], and often there will be one in someone's pocket or car. The term 'field expedient' applies. Split bolts can also be found in stainless varieties in case the materials being joined might not like touching copper. Not a great selection of sizes though. Not that anyone uses anything but 99.999% pure "oxygen-free" copper. ;) e.g., > https://www.kencove.com/fence/Split+Bolt+Line+Taps_detail_CBTPSS.php 73 de w4kaz ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Lazy question concerning toroidal inductors
Not enough information. How many turns? How much current through inductor? What core size? What material? Do you already have a particular core you want to design around? What Q do you need from the standpoint of antenna efficiency? Is Q only a thermal issue? As a VERY general rule, Q is somewhat higher with more turns, so you would want to just use smaller wire and increase the number of turns. Books will not tell you this fact. It's a second order effect having to do with leakage inductance. You should confirm it in your case by making comparative Q measurements. Rick N6RK On 8/6/2012 7:29 AM, Tod Olson wrote: > I am sure [or at least I hope] I could sort through the information > available in books and on the web for the answer to this question, but > maybe someone reading this reflector can give me an 'instant' answer > [preferably correct]. > > I intend to use a powdered iron core toroid as the form for an inductor > which will be used in a matching network at the base of a vertical. The > wire size is #16. Since I have already fabricated and measured a couple of > these inductors, I know the number of turns needed to get 5.5 uH. I need > 11 uH so I put two in series and the expected 11 uH was measured at the > frequency of interest. > > The question I pose is: > > Is it preferably to use two of these inductors in series or use two > stacked cores and the requisite number of turns to get 11 uH? The expected > current through the 11 uH is about 3 amps if the Q is about 100. Will the > Q be different if there are two inductors or one inductor made using two > cores? [same size wire]. > > All comments are welcome. Even suggestions about where to search the web > for an answer or where to look in a book for the equations that will > resolve this matter. Or suggestions on where this has already been > discussed. Or suggestions on the steps to use to quickly get the answer. > > I suspect that this is part of the 'lore' that has been developed which is > why I am asking the question rather than trying re-invent the solution > using first principles. > > Tod, K0TO > >> > > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Lazy question concerning toroidal inductors
I am sure [or at least I hope] I could sort through the information available in books and on the web for the answer to this question, but maybe someone reading this reflector can give me an 'instant' answer [preferably correct]. I intend to use a powdered iron core toroid as the form for an inductor which will be used in a matching network at the base of a vertical. The wire size is #16. Since I have already fabricated and measured a couple of these inductors, I know the number of turns needed to get 5.5 uH. I need 11 uH so I put two in series and the expected 11 uH was measured at the frequency of interest. The question I pose is: Is it preferably to use two of these inductors in series or use two stacked cores and the requisite number of turns to get 11 uH? The expected current through the 11 uH is about 3 amps if the Q is about 100. Will the Q be different if there are two inductors or one inductor made using two cores? [same size wire]. All comments are welcome. Even suggestions about where to search the web for an answer or where to look in a book for the equations that will resolve this matter. Or suggestions on where this has already been discussed. Or suggestions on the steps to use to quickly get the answer. I suspect that this is part of the 'lore' that has been developed which is why I am asking the question rather than trying re-invent the solution using first principles. Tod, K0TO > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: 160 Meter Tuning Question
> How much series C will it take to resonate a set of three guy wires 120 > degrees apart that are 145 feet long each. > > They are fed at the 60 foot level of a Rohn 25 tower, and slope down to 10 > feet at the ends. They are guy wires that cannot be changed. > > I want them to resonate on 1.830 khz. They are to be the elevated radials > for my vertical. Why do you want to resonate them? The shield voltage is what drives common mode onto the coax. With the radials slightly off-tune, the only problem is the shield connection voltage is a bit higher. Voltage driving the shield is never near zero anyway unless the ground system is very large. If it were my system, I'd be using a reasonable isolation on the coax shield anyway. Maybe something like 500 ohms or more, with the shield grounded on the house side of the isolation. Then I'd just tie the radials together and series or shunt tune the radiating element with a single capacitor to compensate any reactance. Series tuning would not modify resistive part of feed impedance, shunt tuning would change it to a higher value. Say it was (just guessing) 35 +j30 at the feedpoint. A series 30 ohm reactance capacitor would make it 35 j0. The parallel equivalent impedance would 60.7 +70.8. So if we parallel tune the reactance out with a -j70 shunt capacitor it would be 60.7 j0 ohms. With two caps, one series and one shunt, we could make it 50 j0. I'm not sure what the impedance would be. This is just to illustrate if shield voltage is made a non-issue with an isolator on the shield, the radials can connect to the shield without any care in tuning and it won't change a thing except reactance of feed impedance. That error can be corrected equally on either side of the coax, because we all know a feedpoint always has the same current on each side if the coax is not radiating. Of course some people write entire articles about Kirchhoff not applying to RF, but we know that isn't true if we understand displacement current (stray capacitance). :-) 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Soldering in the wild!
I believe the whole idea of the split bolt is that, properly tightened, it exerts enough pressure to crush through any existing corrosion and make a joint that is too tight for corrosion to intervene. 73, Pete N4ZR The World Contest Station Database, at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 and arcluster.reversebeacon.net, port 7000 On 8/5/2012 6:38 PM, Guy Olinger K2AV wrote: > Then pressure has been enough to keep corrosion from between the > clamped items...Thanks, Guy. > > On Sun, Aug 5, 2012 at 4:16 PM, Jim Brown wrote: >> So far I have not done so. >> >> Jim >> >> On 8/5/2012 11:21 AM, Guy Olinger K2AV wrote: >>> Do you treat the connections with anything for corrosion protection, >>> e.g. silicone grease? 73, Guy >>> >>> On Sun, Aug 5, 2012 at 2:31 AM, Jim Brown >>> wrote: > I use copper split bolt connectors, both forelectrical and mechanical > connections. >> ___ >> UR RST IS ... ... ..9 QSB QSB - hw? BK > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
