In order to illustrate an article on temporary tower-raising, I put together a simple sum-of-forces diagram. Being a "milliamp and solder" guy, I don't trust my ability to recall college-days Statics
As one of the report authors, I thought I should jump in here. The antennas were working models, borrowed from their owners for the tests, and assembled following the manufacturer directions to the l
That is what we observed on 10 meters, Peter. On 20 and 15 meters the antenna seemed more or less OK, if unspectacular. The reference antenna was a full-size dipole on each band mounted at the same h
A clarification - there are two basic mechanisms in play regarding the effect of the feed line's outer surface. Each influences the antenna pattern and SWR but in different ways, sometimes creating t
My post should have read "...and restricts current flow TO BE from the inside of the shield to..." Sorry about that. Too many edits :-) The point of the choke balun is to block the current trying to
This is a common precursor to trips to the Emergency Room for older adults, usually male. The most usual situation is working on a ladder - like cleaning gutters or putting up lights or something. P
I am *so* glad to see this pointed out...thank you. That which turns is the rotor. That which causes the rotor to rotate is the rotator. But ham jargon is what it is. 73, Ward N0AX Just a thought....
In the application of turning antennas, yes. I don't think Norm's Rotor Service is going to change their name, though :-) Hams also use the terms duplexer and diplexer improperly most of the time, to
I spent the weekend putting in about a mile of radial wire in rocky soil, so I have missed most of the fun here on the reflector, apparently... Anyway, some of the poor performance by the Mosley PRO
and the fact that someone was excited about ham radio and field day is a *great* thing. Amen. Bring on the Baofengs... Some will wind up in the junk drawer, but some others will wind up doing cool st
Here's another off-topic opinion piece - My equipment is homemade, some at the component level, some at the board level, and some at the module level. I have finished the receive side, and am working
Stu K6TU has put together a very nice web service for obtaining the data - see the Antenna Book's supplemental web page: http://www.arrl.org/arrl-antenna-book-reference. The instructions for HFTA poi
Use a proper clamp designed to connect copper wire to galvanized tower legs. For Rohn 25, the clamp is part number R/CPC-1.25 and I'm sure there is a larger one for Rohn 55. A local electrical supp
and have had multiple direct lightning strikes. The mechanical forces on a conductor carrying kilo-amp currents from a lightning strike can be extreme - many pounds per foot of conductor. (This is d
A quick reply - yes, the stainless steel shim clamps can be used *in some circumstances* but my understanding from Polyphaser folks was these are not to be used as primary grounding clamps for heavy
This is one of those "what problem are you trying to solve" issues - ac safety, lightning, or RF management? Towers should have an ac safety connection between the tower and the station/house ground.
radio. My approach, when discussing baluns, is to present the "balun" as a "function," not necessarily a "thing." The balun "function" is to transfer power between balanced and unbalanced systems wh