If you're putting filters between the device under test and the analyzer and need a correct impedance measurement, don't forget to account for the transfer function of the filter. I had W3NQN build a
Does anyone have experience with Jefa Tech coax cable? Their equivalent to LMR400 is less than $0.50/ft on a 500ft reel, quite a bit cheaper than Times Microwavave product. Their customer list includ
I recently purchased a used tower, complete with a full set of EHS guy wires, from a ham some ten miles from the US East coast. While the tower itself and the guy wires are in excellent shape, the u-
David, I don't see any connection to the shield of the coax used in the driven element or the reflector (see drawing, "Center Conductor only is attached to feedline on both ends!"). It looks to me as
To the tower knowledgeable: Rohn's mechanical drawing of concrete bases for guyed towers shows a "bearing plate" on top of the concrete base, apparently concentric with the pier pin. I can't find suc
I need some help from the more structurally-oriented members of our fraternity. I need to know if it is practical to erect a 75-foot vertical element from aluminum tubing that has the following dimen
Mention was made of simulating with NEC to see what one would get from a particular stack. Assuming the results are not what one wants right out of the gate, how can one optimize the antennas to get
I am putting up 80 ft of Rohn 25. I am using the steel guys that are part of the extension to the AB577 system. The benefit is they are one-piece, adjustable in length and available to me since I'm t
That's WHOA, fellas, I'm only talking about using the '577 guys as temporary guys - one should NEVER think of using anything substandard for a permanent installation. That would, indeed, be asking f
I purchased eight sections of used Rohn 25G last summer and it's finally going up. While test fitting the sections, I find that I have one "stubborn" section - it will not go onto nor will it accept
I want to thank everyone for all the helpful and practical suggestions. I will first determine if the leg diameters are the same, then check alignments and do what I can with "gentle persuasion" to m
FYI: the jack in my 2004 VW Golf is perfect for separating Rohn 25 sections. The "tongue" has a piece of channel that engages the Z bar securely. I place a plank across the "opposing" Z bar to ensure
I was surprised to get a competent-sounding person on the phone when I called BoltDepot.com to find out what grade of steel is used for their hot-dip galvanized bolts. Having vastly exceeded my expec
No sooner did I decide to use grade 5 / zinc plated bolts, than I found a company called GME Supply with a limited range of 3/8" galvanized grade 5 steel bolts and overtapped nuts in exactly the leng
I have obtained several aged yagis that I intend to rebuild. The elements and booms have various amounts of "gunk" on them - ranging from atmospheric crud to left over tape adhesive to oxidation wher
I'm trying to clear up a point of my own confusion and/or ignorance w.r.t. "thrust bearings." I used to think that the "thrust" taken up by the bearing, e.g. when supporting an antenna mast, was a ve
Paul, I inquired directly to Rohn for a definitive answer to this pesky question. Contrary to the definition of "thrust bearing" that appears in other sources, Rohn says their TB series are meant onl