Adding guys to a self supporting tower generally raises the allowable wind load and donīt make it fail. If the force of wind blows across guys would be transferred as downward force through the tower
If the two verticals are separated a quarter wave length apart you will feed them in phase for broadside. For endfire you need to insert a 90-105° phasing line into one feed line. I did that on 80m a
Yes, I have a three stack of 5L KLM yagis. The lower two are hard wired phased and fixed direction U.S. If I add the highest yagi to the stack I almost always get 10db higher differences reported fro
Hi Dan, Yes, itīs all dependend on the skip angle and the nulls. The addition of the highest antenna resembles an amp at the very low angles only. I use 13m spacing and EZNEC predicts the following o
Hi Clay, Exactly! My answer to Dan overlapped with yours 73 Peter When comparing antennas, you can't just look at the maximum gain, you also have to consider take-off angle. When you add the highest
I found 40 seconds for one rotation real nice for contesting after I built my own rotator. I turned a christmas tree of 5 element yagis 20-10m + 3L FS on 40m without problems, but the stress on the d
Hi Jim, My drive motors usually are 3-phase 400V, so I have no problem to use automated ramping with a cycle inverter now. But first I need to add an additional position indicator to supply informati
The better is the enemy of the good. Think about it... Rick, You must have a bad hair day!! If I get great reports and I'm happy with my antenna, are you telling me I shouldn't be? Think about it...
I donīt think so. And 3.5MHz x 3 = 10.5MHz. 73 Peter, DJ7WW The harmonic relationship between 40 & 15 has always been a problem if the antennas are too close. The ratio between 40/15 (7mhz X 3 = 21mh
Yes, that should work. You could also detune the boom by connecting a capacitor across part of the boom. I built a new 40m FS yagi (12m boom) at 38m, about 50m apart is my shorty-forty at 18m height.
You must have been a lucky man not to carry the tower with the multiple beams ;-)) 73 Peter, DJ7WW I actually participated in carrying a 70 foot tower with multiple beams from one location to another
I donīt agree. The stack match is a more complicated and expensive way to do the matching. The easiest, less expensivest and imho best methode is series matching. http://www.seed-solutions.com/gregor
Hi Tom, If you put a vertical with just one elevated radial on your rotator it is nothing more then a bend dipol. A dipol in theory might have 3db gain against a quarter wave as you doubled the numbe
All sucessful antenna developments are done by EZNEC or similar NEC based software nowadays, I also use it extensively and the results always do work as expected from the beginning when converted int
You will not need just the equipment and the test range, the adjustable distant tower or building to reach into the center of main lobe is important as well, especially for measurements on horizontal
Many contest and VHF stations do that. Long boom yagis need a lot of turning radius and spacing. I am going to built one for 10m if the band improves. 5/8 wave length stacking distance is imho the mi
My modelling for the planned 4x104CA stack is done by EZNEC and HFTA. I did not write that the vertical stack of 4 yagis cannot provide a desired 10° vertical lobe. Of course it can by proper combina
If you donīt need active noise cancellation I like to suggest the Sennheiser HMD46 which I use. http://www.sennheiser-aviation.com/air-traffic-control_500466 As I am wearing glasses and having a rela
Hi Tonno, Check the technical data page of the HMD 46-3-6. The mic capsule is a dynamic one with a 200 ohms transducer. I use it on all my radios, Icom transceivers IC-751A, 765, IC-740 and Flex SDR-
Hi Tonno, All HME version are electret, you have to look up the HMD 46-3-6. http://www.sennheiser-aviation.com/air-traffic-control_500466 73 Peter That is strange, I just checked the page: http://www