You can also make the vert longer than 1/4 WL and that will raise the R but introduce Xl. Fortunately a series cap fixes the Xl. I believe that higher natural R **may** offset a bit the effect of t
Step by step: Draw a square on a page of paper. Draw a line from one corner on one side, to the opposite corner on the other side. You should end up with what looks like two mirrored triangles. Tha
Bob, My 2 cents here. There is a practical answer and an ideal answer to the "which direction do my radials point." My answer is that you space them so that they are not overlapping and share the ma
Steve is right on the short stack. I run a set of the JK402T here - which is the Moxon-like thing JK makes - at 70 & 140'. Works pretty good and has nice BW & good F/B compared to what you would exp
I agree with Mac. Fred is THE MAN for this kind of stuff. Even here, where the local zoning regulations specifically ALLOW ham radio towers, the amount of governmental nonsense and various other pla
Kirk, Almost all the chokes I've used in the last 10 years have been built loosely around the K9YC cookbook. Those are generally speaking a couple of type 31 ferrites with a few turns of coax runnin
I guess I'm missing what's the "very bad idea" part of this. We are talking RF here, not lightning. Right? Antenna in the middle of this field, right? If I'm following the explanation, the guy is
Jim, if what you are saying is the case, then yes, I agree. I would add that I am pretty sure that a lower band parasitic vertical array (an inverted L is a top loaded vert in reality) needs a VERY E
Got two. Love em. 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com [X] Dale M. Schwartz SCHWARTZ | POSEL Immigration Law Group Suite 450 RiverEdge One 5500 Interstate North Pkwy., NW Atlanta, GA
Further to Grant's comment, the N6LF info is available, free, at the N6LF web site. That series of QEX articles really should be the first stop for guys wondering about their ground system effectiven
Give the GH guys a call about your concern. I've got a trio of those controllers here and they have served yeoman's duty. Jeff @ GH is usually the guy who replies and for sure, he's seen it, done i
Picking the "right" 40m beam is hard. So I appreciate the struggles the OP is going through. I went through this same process when putting up a 40m tower a couple of years back. 40m seemed the toug
Ah, but it can be, just not in the way guys generally think about... A 2 element beam gain increases with coupling. And that in turn drives the feedpoint Z downward. In fact this characteristic can
Redwings. Expensive but after a day on the tower, your feet will be very very very happy!!! 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com Ditto for Redwings. Non-steel toed for climbing. Vi
Without doing any actual engineering statics work, is there a rule of thumb for truss height for helping to offload boom sag? I've got a LJ205 that's been recycled to a 10m OWA. The back end of that
Thanks for the many comments on this. Great feedback!!! 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com Seems to me, this the heavier duty truss I suggested and installed at your place. Glad it
Back in the attic antenna days, I used a trap 160/80 at the house. Was running CW & RTTY then and kept frying coax type traps. As they heated up the SWR would move around and you could see it on ke
Pete, The common mode choke - that's how many turns and what material? For 160 something around 8+ turns & type-31 are the "right" rule of thumb answers. Fewer turns or using (example) a type 43 mat
These guys are right about the radial count, in the absolute sense. But it's a matter of perspective. The difference between 8 short radials and 64 long ones is about 3 dB per N6LF. That's half an
Both good here. 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com Sent from my iPhone I've written a Windows program that calculates ground permittivity, conductivity, and skin depth using impedan