<< My preference for antenna wire is Alum-O-Weld >> Interesting. We tried #12 alum-o-weld for long wire antennas (over 300' on a leg) and found the DC reistance too high. Maybe its okay for shorter a
What is a QSO Party? Tom, KN5RRC -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: o
<< let's remember what aluminum does when it oxidizes. bare aluminum in moist air will form a grayish, NON-CONDUCTIVE oxide. if we want two pieces of aluminum which are mechanically coupled to be hav
<< Or, how do you get bandwidth on a dipole? >> 1. Use a 1:1 ferrite choke at the feed point (Aztec preferred) or a coax choke. 2. Use 12 gage wire (14 minimum) 3. Make it horizontal and get it at le
Actually, in the early seventies, we mounted a 20 meter ground plane on the candelabra of a 1200' tower near Houston and put the rig in the transmitter house (at the same height). In the short time w
Half wave slopers generally model better than low dipoles and much better than inverted vee's (for low angle). I've had very good success with half wave slopers from a 60' tower. Tom, K5RC/7 -- FAQ o
You should have done some research before you started. In the seventies, Dr. Bill Schrader, K2TNO, did similar research on a stealth antenna and published his findings in the Armadillo Press. His ane
The effects are very dramatic. First, the choke tells the RF where the antenna ends and the feeline begins. Second, it minimizes the effect of RF propagating down the coax and back in to your shack.
<< Actually, what it really demonstrates is how important a dB or 2 can be, and that the cheapest, quickest way to a better signal is to go QRO (no flames please!) There is an axiom in ham radio that
<< >80-meter dipole. Sez he feeds it with 50-ohm line, cut by formula for I have done the same thing and have had the exact same experience using a quarter wave of RG6. I also wind it into a coax cho
<< I happened to remove the 8X jumper that goes between my antenna switch and swr meter, so now the antenna coax was hooked up directly to the meter, and noticed that my swr and bandwidth changed on
When did we rescind the laws of physics? How can transmit and receive gain of the same antenna be different? Tom, K5RC -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertal
<< Okay, another person with a low dipole is venturing into the tower arena. I'm looking at a US Tower 40 or 48 foot free-standing tower, and then either a tribander and a separate 40 beam, or a 10-4
<< Let me conclude that, if you were to perform the calculations yourself, you would be amazed at how much of a safety factor that Rohn uses. You wouldn't believe at how much more windloading you can
<< Very confusing. I never heard of anything but 5 element HyGains. K4VUD >> In the 1960's Hy-gain did make a series of "Long John" arrays that were very heavy duty. If I remember what the Hy-gain re
On chrome moly, once the surface rust coat forms, the rust process slows down dramatically. The question becomes do you want it to last 50 years or 55 years? If the mast is not capped, any rain or co
<< Not necessarily. Some alloys are designed to be self-healing. That is, their surface rust prevents the oxidation from progressing further. If the coating of rust is scratched, the scratch rusts an
<< Rohn 25 is good for more than vhf/uhf.... Follow the mfg's installation guidelines, guy it properly, and if you are swinging big beams use a bridle on the top set of guys... My 150 footer has a 4
<< Animal chewing on wires! And, the anger of trees not yet fully covered! I >> My first antenna farm was shared with several horses who liked to chew. I was told that when we handle the coax, rotor
I fear that we are making this thread more complex than it has to be. A "Balun" (Balanced) (Unbalanced) is a device to adapt a balanced feedpoint (tee match, omega match, dipole, etc) to an unbalance