Actually, I think I was a bit skewed in my reply to Larry. Although I personally have no problem with connecting a rebar cage to ground outside of the concrete, Larry didn't actually suggest that the
This whole thread illustrates the dangers of making generalizations. There are so many factors that affect antenna performance, even well constructed ones, that in my opinion it's not very objective
Sorry ... I missed that. I even searched through the archives to check, but apparently I overlooked Bill's post. 73, Dave AB7E _______________________________________________ ________________________
I'm not sure that the LMR400 would need it, but I've done the exact same thing for other cables (rotator control, etc). I wouldn't use thin wall PVC, though ... it generally has horrible UV performan
Any chance that individual is willing to post said engineering analysis to his company's web site? It might be amusing to read. 73, Dave AB7E _______________________________________________ _________
In response to N3OX's posting on cage dipoles, I searched around to find more information on them and happened to find the website of a manufacturer who also claimed better performance than a standar
Andy, I don't know how you arrived at that conclusion. It simply isn't true. Dbd "could" be referenced to a dipole in free space if so noted, but there is no convention that says it always is, or tha
That statement hasn't been accurate for about three decades. Mechanical engineers now understand and can model exactly how bumblebees and hummingbirds fly. The only reason the myth lives on is becaus
N3OX just corrected my flawed memory ... it was K4SAV who originally wrote that description of a half-sloper. My deepest apologies for the misquote. 73, Dave AB7E ____________________________________
I agree. When I wanted to paint my heavily galvanized AN Wireless tower with a dark color for stealth reasons, KK3AN (the owner of the tower company) recommended I simply use a good exterior grade la
For what it may be worth, the picture at the link below was taken roughly 300 feet distant from my tower. The tower is 70 feet tall, four feet across at the base tapering to about 20 inches across at
I assume those modeling programs are the same as EZNEC since all three use the same NEC-2 engine, and EZNEC does not allow stepped diameter correction if you have loaded elements unless the load is a
I think that depends heavily on the type of soil involved, and how the soil is compacted. When I backfilled under the slab of my house (behind the six foot high retaining wall) I removed all rocks, l
It's better to search on the pieces instead of the whole ... Wikipedia says that wooden utility poles are typically made from Douglas Fir or Jack Pine, among others. A Google search on <douglas fir d
That's like saying a 2 inch air gap is going to break down at the same voltage as a 1 inch air gap because the first inch will break down and then the second. And no, the voltage is a maximum at the
No it doesn't. The end is the end, and there isn't any current flow at the end of a wire ... unless you have arcing out into the air or something obscure like that.. Besides, he was clearly referring
I give up ... Dave AB7E _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mai
I did a quick model of your proposed antenna with EZNEC assuming #14 wire and it said that you'd need about 52 uh to make the system resonate at 1.83 MHz. The resulting feedpoint impedance would be a
I also I got 45 uH if I assumed a 3 inch vertical element .... 73, Dave AB7E _______________________________________________ _______________________________________________ TowerTalk mailing list Tow
That's a very flawed comment. Reception is a function of signal-to-noise ratio, not absolute gain. People can hear great with all sorts of receiving antennas (small loops, beverages, etc) that make h