JC caught a great big OOPS! Dimensions for 8' ground rods are: 8' into the ground and 16' apart. Thanks, JC. 73 de Red _______________________________________________ ________________________________
Good point, Don. The ground potential, voltage on the ground wire, for the power company may have risen during the strike because it (and your station ground that was tied to the power company ground
Hi, JC; I had been pondering your earlier post regarding need for a perimeter ground or loop. PolyPhaser made an argument in their earlier book, Grounds for Lightning Protection, for this and I obser
Sri, gang; the Scot, Maxwell, and the Englishman, Heaviside, decree that RF will still concentrate on the outside of a conductor. The distribution of current in depth is an exponential function, but
Lightning may have been incidental to the pinhole leaks. The water in some communities slowly corrodes copper pipes and causes pinhole leaks. I believe it is a result of acidic water, but I don't rem
Hi, Randy; I'm forwarding your text to TT for you, with this response. My response is, "Thank you for the information." If I understood you correctly, most leaks are not caused by lightning, but some
Hi, Gang; I scribbled a few calculations concerning the temperature rise if a copper pipe filled with water conducts a lightning strike. I assumed a 0.5" OD pipe with 0.050" wall thickness and I assu
Hi, Ben and TTs; Aluminum may fare better than copper in acidic ground but alkaline ground will corrode aluminum. Jim Lux raises an interesting suggestion regarding sacrificial electrodes that might
Hi, JC; I will answer you question more directly than in my first response. I apologize for missing your direct question. I recommend branching from the tower legs, to ground each leg independently.
TTrs; JC asked me a question, see following my response. I can answer regarding grounding for lightning protection, but will defer to others who know NEC much better than I do. Hi Red, Just a quick q
Hi, Tony; It would be good to know the pH of the soil where the aluminum was. Will you please report that? 73 de WOØW _______________________________________________ __________________________
Stranded wire or cable is acceptable. Braided cable is not acceptable. As skin effect forces current to concentrate in the outside layer of wire and as the strands in braided cable change position fr
In addition to stacking, feed one through an adjustable phasing network to steer the pattern to the desired vertical angle. 73 de WOØW _______________________________________________ _________
Hi, Ms. Mitchell; The tower provides protection similar to that of a lightning rod on a house or barn. However, the protected volume under a lightning rod a few feet tall is often modeled as a cone,
Hi, Dick; In option 2, only the feedline radiates. The dipole acts as a capacity hat. This is called a TEE antenna; it is usually implemented with open wire feedline. It needs several, like more than
Hi, David; Lightning protection is achieved by minimizing differences among all the conductors associated with the station (or computer or other equipment or person). Start by minimizing ddifferences
The dipole can be protected as effectively as other ungrounded antennas. Of course, the antenna, being at a higher elevation than other station components and utility lines, is certainly a target of
An Ohmmeter should read a fraction of an Ohm from antenna terminal to case through an inductor and many KOhms from rig to case through a static bleed resistor. It should read open from antenna termin
Hi, Jim; If your are working HF, a few 2 watt carbon comp resistors in parallel will work Put them in a can if shielding is required, but derate the dissipation somewhat and consider heat sinking the
How the memory slips! We used to use light bulbs as dummy loads. It requires some experimenting and measuring to find bulbs that present a suitably matched load for a given power, but they work fine