If you have some 75 ohm coax available you can build up a series matching section: 153 degrees 50 ohm coax connected to the feedpoint followed by 146.5 degrees of 75 ohm coax. You can also make a stu
Terry, I like your numbers better as they use less coax. My series match program has a flaw that I never noticed in all the years using it: inputting 79 +j.01 gives my numbers and inputting 79-j.01 g
Phil, there is an additional answer to this that you may prefer: Since the antenna is already connected with 50 ohm coax, you can determine the R+j at the end of the coax and apply a series match the
In general, windload is referring to the force in pounds caused by the wind blowing on an antenna or other structure(s). For this to be meaningful the associated wind speed has to be given as well. I
Bill, the Rohn TB3 is designed to fit their 25AG4 top section as well as the BAS25G and BPL25G top plates. The top section and plates have a large hole to also allow use of the TB4 3 inch bearing. Th
Phillystran grips are VERY different from EHS grips: They are made of galvanized steel and this makes the appearance quite similar. The much lower manufacturing volume, increased amount of material a
Phillystran does not offer the end sleeves for locking the grip ends. They are made for steel grips but rarely used. It is possible, total conjecture on my part, that one of the larger steel end slee
Pete, please keep in mind that the hairpin will add some inductance across the feed point. This means the d.e. length will need to be slightly reduced compared to a tee match arrangement. This has no
One added thought that will help reconcile K1TTT's experience with others on this subject: 3dB coverage of about 3200 miles in width. From this part of the world, that path would be about 1500 miles
Noel, 3.6 uH has a series reactance of about 40 ohms; a Q of 289 equates to a series loss resistance of about 40/289 or about .14 ohms. At 1500w there could be about 6.5 amps of current flowing throu
Don't forget to polish the elements so there won't be a hazard to birds! 73, George T. Daughters, K6GT _______________________________________________ _______________________________________________
Larry, the Farmtek anchors do appear to be very similar to the Rohn Anchors. They are not hot dip galvanized so that is one difference. What we are seeing here is the cost impact of a value added pro
Also, you could purchase about 100 permanent magic markers and open them up, pour in a container and soak your aluminum in the solution. Just kidding, just kidding. 73, Gerald K5GW In a message dated
No help with the hardline but there are four different 8 conductor rotor cables at _www.texastowers.com_ (http://www.texastowers.com) . On the first page do a search for R81 or R82 or R83 or R84 to f
First hand feedback: a full sized 80m 3-el yagi (1200 #) will windmill a large prop pitch with about 45 mph wind. This is for a very well balanced design with equal element spacing. You can't imagine
After five years of not selling a PR25G, we gave up carrying them. The Glen Martin roof towers have basically killed the PR25G as they are self supporting and roof mounted 25G is not. 73, Gerald K5GW
Clay, if you can find an old (maybe 20 years ago) Rohn catalog, they listed the section wind loads in pounds per lineal foot, based on 70mph wind. You can convert those numbers into equivalent sq ft
Ron, you are caught up in the Shackle working load vs guy cable breaking strength quandary. Typical breaking strength (actual number undocumented) is four to five times the working rating. If you acc
John, I would not even think about guying a tower with 1200 pound guy material. In my opinion the material you have is exactly what is needed for that job. The 1200 pound size is used primarily for g
I can help with this question: Glen Martin no longer offers a thrust bearing. They are suggesting use of a Yaesu GS065 as a substitute. The 45AG4 and BPL45G both have a 3" i.d. hole where the bearing