Perhaps a less error prone way to measure loss is to use your transmitter, dummy load, and SWR/power meter. I put the power meter at the transmitter and set the power level on the SWR meter. Then mov
agree, McMaster has awesome choices, much inventory (I can't recall a backordered item), and also better prices than Fastenal. They ship from NY, LA, and Chicago. If you order regularly, they frequen
Agreeing with Roger, having just completed building for a friend a new cage for a Tri-Ex LM354, I welded the main #8 rods to the tower mounting flanges (3x3/8x20" HRS). This is the way it comes from
"Shorty forty" is a term subject to much interpretation. The biggest challenge with the W6NL Moxon is more likely getting it on the tower with the Moxon tips. Even more so with the smallest 2L 40m, a
I melted the commercial "HD QRO" bead type choke off my GOTA G5RV feedline junction and since then only use the FT-240-31 cores stacked 3 or 4 at QRO with TFE coax (RG142 double silver) turns or the
Certainly there is enough clearance on a diagonal brace. Make a clamp from SS shim stock and a couple of SS bolts. A single 8x12" sheet will do a half dozen clamps for $10. http://www.mcmaster.com/#s
I also think Al's math is incorrect. My frequency counters measure intervals to nanoseconds, better ones can to picosecond resolution, these are standard features on better frequency counters. So one
Your engineer can design a spread base that handles the load. More concrete, wider, but about 3' deep as a guess. It is an alternative I considered for elevated guy anchors. Grant KZ1W The concrete g
Thanks to Dan AC6LA, who recently posted the Cebik article link that explains a good way to model fan dipoles. Cebik article on using "zero" length transmission lines to connect fan elements: http://
It's worth a look at N7NV's FEA analysis of guyed towers to gain some understanding of what is going on. http://k7nv.com/notebook/towerstudy/towerstudy1.html If the tower is bending under load (and I
It "has always been that way" means somebody thought it a good idea. I think the joint is not "slip-critical" that is the bolts tight enough that the friction between the two sections is taking the l
here are the Portland Bolt torque specs for grade 5 bolts which I found is the grade Rohn supplies for R25 size-tpi proof load tw tg tp 1/4-20 2700 2025 4 11 8 5/16-18 4450 3338 9 22 17 where load is
I'm trying out some of these in a QRO remote antenna switching application SPST, so far so good. What is different in the (clever) design is the coil isolation is 5KV. The contacts are rated for enou
Or use SDR35 drain/sanitary pipe, available at commercial suppliers. The strength is much higher than HD perf pipe but less than SCH40. Available 4" and up with glued or gasketed joints (used for san
The basic control/indicate design is the same in all, as far as I can tell. A 500 ohm pot inside the rotator and a servo in the controller that nulls an inside pot to match (not sure the value). The
I did get the 2800SDX controller working properly with a G1000 rotator, interesting that the 2800 controller has the ramp down speed to stop logic/ckts in it and they work ok also. However, somewhere
Well, you might notice a couple of db F/B with that one radial you selected. That would be a big win with the overall antenna maybe 5 to 10 db down from a decent radial system. Verticals at salt wate
Done this on my controllers. The Jones Series 300 6 pin part numbers are chassis socket 38330-0506 fits Yaesu hole and screws cable plug 38331-5606 cable socket 38331-8006 in case you want to make an
White Cap has a decent selection and free shipping this month. Had my Guardian 12111173 full harness on today. 2 side D rings, 2 chest small D and the rear D. wide belt. $94. Don't think I need more
With Field Day coming, I need to build some line filters for a multi station setup. The goal is two-fold, reduce hash from the Honda inverter-generator and reduce conducted noise from other stations.