Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
-- Listen to Alternative News and Conversation You Won't Hear On Commercial Radio. Visit http://live365.com/stations/pascoradio YOU HAVE BEEN WARNED! First Time Users May Be asked To Do A 1 Time Setup. "Jack Painter" wrote in message news:r4_Rc.12079$Yf6.1279@lakeread03... "Harry Conover" wrote (Private) wrote in message . com... Hello, I am looking for some advice on if the ground system featured below is sufficent or should be upgraded. It consists of: - 3 ground rods 10' each around the tower (bonded together) - 2 ground plates (one outside, one in the shack, also bonded together) - lightning arrestors and/or feedthrough adapters - tower to mast ground - interior coax switch (not shown) I provided some pictures below: http://www.telusplanet.net/~homac/exteriorground01.JPG http://www.telusplanet.net/~homac/exteriorground02.JPG http://www.telusplanet.net/~homac/exteriorground02a.JPG http://www.telusplanet.net/~homac/exteriorground03.JPG http://www.telusplanet.net/~homac/exteriorground04.JPG http://www.telusplanet.net/~homac/interiorground01.JPG http://www.telusplanet.net/~homac/interiorground02.JPG I am looking for constructive feedback..... Thank-you.... Lloyd Hi Lloyd, Looks like a nice installation, although your grounding rods might be placed farther apart, or augmented by some heavy gauge radial wires (depending on your local ground condictivity). What I did note missing was the mention of 'lightning chokes' wound in the coax lines decending from the tower. These are basic to lightning protection for broadcasting towers, but I've rarely seen them implemented by hams. The idea of a lightning choke is to add a small amount of inductance to the coax so that if a direct lighting strike happens, the instantaneous current flowing though the outer jacked of the coax into your lightning arresters will at least have some amount of impedance limiting the current magnitude, thus reducing the probability of destruction of both the coax and the the arrester itself. These chokes are more often than not implemented by winding a dozen or more turns of coax around a form (say a 4" diameter phenolic tube) prior to the arrester or spark gap. Harry C. Harry, that winding of coax may be useful as an RF choke, but it is most certainly not a lightning choke, and will act more like an air-wound transformer than anything else. Not only is this not specified for any lightning protection systems, it is specifically warned against in many. Jack Painter Virginia Beach VA Hello All. First let me comment that the lightning mitigation techniques used are better than many ham installations. That being said, I would increase the conductor size between the tower legs and the ground rods. When I saw these, I thought a "fast acting fuse." The amount of current that the tower can handle cannot be safely terminated to ground with smaller conductors. Also, the screw terminals need to be checked periodically because they will loosen themselve due to "cold flow." Why not repace them with crimp types and then solder the crimp with a torch as a back up? I am asuming that this device is covered by something to protect it from rain, etc? John-WA4JM, Dade City, FL, home to some of the most ferocious lightning activity in the western hemisphere. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
30ft Tower uprooting | Antenna | |||
Advice Needed for Super J-Pole Design: Inductive Loops Overheating | Antenna | |||
EZ Way tower sheared hinge pin conclusion(?) | Antenna | |||
EZ Way tower sheared hinge pin | Antenna |