I have had good luck with this site. U bolts-- http://www.jschmidtstainless.com/Products/ublt.htm They specialize in stainless steel hardware but only have a limited supply of U-bolts. I have purchas
Tim-- The only problem I see is that Kopr-Shield is recommended for copper to copper connections ONLY. Whereas Penetrox is designed for aluminum to aluminum or aluminum to copper use. --John W0UN Kop
The velocity factor in foam coax is the most difficult thing to control, since it is a function of the percentage of air bubbles in the dielectric. Some manufacturers specify it for a range of values
I am spoiled ROTTEN! In the old days I used an HP-8405A Vector Voltmeter. But now I use an HP-4195 Spectrum/Network Analyzer. I can cut a tenth inch off and watch the null shift by a few KHz. It make
Coaxial cable delay lines for phasing HF antennas are really not all that critical, at least for peaking the signal, but if you are trying to precisely position a null then better accuracy is require
This was best demonstrated by OH8OS in his paper about phasing his 2 x 3 array of 6L 20M KLMs -- 2 wide by 3 high, for a total of 36 elements on 20M. He had the capability of rapidly phasing the arra
When I was at the University of Missouri a group of us lived in an old, 2-story house, with a HIGH attic. I bolted my Ham-M rotator to the floor of the attic, directly under the peak of the roof, and
Waterproof??? This was a rental house! ;-) Actually it WAS a rental house owned by the University and scheduled to be torn down and turned into a parking lot once our lease ran out. Actually I offset
Actually the venerable 204BA was on a 26 ft boom. Not the best in times of computer optimization but still a pretty good antenna. You don't need to drive two elements to get better bandwidth-- check
Rick-- It is all in the tuning. I like to think of Yagis as band pass filters and the more elements you have the more "poles" you have that you can play with to broaden out the bandwidth. There are l
I once put up an ionospheric sounding antenna in Puerto Rico that was a complex wire array to cover 2- 30 MHz and it was strung between two 100 ft towers that I had installed in a flooded field. The
My concern with weep holes at the level of the concrete is that you have just traded one problem for another. With no weep hole the water can rise above the top of the concrete and when it freezes i
That IS the problem! You just can't tell for sure. And I hate to risk my life and limb not knowing. There just isn't any sort of CHEAP non-destructive testing that I know of. You might make a coil ar
Nothing beats a chunk of UHMW for a bearing. Been running them for MANY years and I know that W7RM used them long before I did. A one inch thick block has been holding an 8L 15M Yagi in the CO winds
There are types of UHMW that are specifically resistant to UV, but white has held up well in the CO sunshine (300 days per year of sun and high altitudes). BUT a PROPERLY designed bearing would not e
Rohn used to supply a wood bearing for ham use. Don't recall if it was OAK or something else but it was adequate for many ham uses. But I went with the UHMW just to see how long it would last. Rush D
Lots of questions and little time. Most ham rotators will take the vertical load just fine. In fact it is hard to have two bearings share this load. But you are correct in that most people mean the h
Gary-- Preloading IS just taking out the SLACK. Taking out the slack in a precise manner. As soon as you pull the guy wire off the ground there is tension in it. The proper slack removal, balanced wi
I have a Loos gauge somewhere, plus a Dillon series dynamometer. I always wanted to put some wire rope in series with some 1x7 EHS so the tensions were equal by definition and compare the readings. O
W2RU Bud--my email directly to you bounced, so I will send this through the reflector. Actual message at the bottom. --John Bud-- Well, I bought the Loos just to do the tests that are in question. Bu