Couldn't it also be a mast that is not the designed size for the rotator, not properly shimmed, so that it binds in certain positions, particularly when the wind blows? I've never understood the engi
I still don't think it would be close, at least so far as forward gain is concerned. I have a 4-element lazy-vee parasitic array, and have modeled the array fed as a 4-square. ~6 dBi is the best you
You are introducing another variable, and I don't think correctly. I just re-read the ARRL Antenna Book's section on vertical and horizontal antennas over real ground, as well as the section on the e
I think Kelly's got a pretty good point. I have a ~3 square foot short 40m yagi 9 feet above a 25AG2 top section, on 2" mast with a .250" wall. The amount that mast twists and wiggles in the wind is
Amen to that. This is particularly true because Rohn's ratings are for projected area, while most antenna manufacturers persist in quoting a more optimistic "effective area" number which must be mult
Another point worth mentioning -- all of these issues (antenna changes, amp or no, RFI) are tied together by a common unit of measure, the decibel (dB). For example, if you go from 100 watts to 1 KW,
The design of a remote switch with up to 4 positions is easy -- the RF design may be harder. For 3 positions, try +DC, -DC and no power, plus a couple of diodes and two DPDT relays. 73, Pete N4ZR Som
And if he gives you the operating parameters of the station, then you can plug them into the web-based RF exposure calculator (U of TX?) and see how the numbers compare with the FCC's exposure rules.
I believe there are a number of different brand-names -- I ran into one quite by accident at a local paint retailer. Can't recall now what the name was, but my guess is that if you describe how it wo
I've noticed that the portable news-gathering vans seem to use an alternative sort of rotation loop for their antenna masts. It looks like they wrap 6-7 turns of coax around the mast, with the top fi
Well, I dunno... I went through a long and painful process of trying to find a point on my similarly loaded tower that would give 50 ohms when fed with a shunt wire and a series capacitor. Never did.
Hallelujah -- I KNEW there was some reason I kept my Palomar, aside from not being able top sell it to anyone! 73, Pete N4ZR Sometimes a tower is just a tower
This reminds me of an episode when we were putting up my tower -- the backhoe digging for one of the guy anchors hit an unmapped corner of the septic field. This was not going to work ... so I had hi
Harnesses are one of those things that people can debate endlessly. I'm a little confused about what harness you got from GM -- did it not have D-rings at each hip? My Klein full-body harness has the
Some 80m yagi designs use coils switched in at the center of the elements to switch resonance from the CW to the phone end of the band. Is it at least theoretically possible to do the same in order t
When I was a kid, I had an 80-meter dipole made of #12 copperweld. The weights we used then were 2-foot lengths of 2-foot diameter oak tree trunk, with a screw eye inserted. Needless to say, they wer
Cringe is right. I think I would only do it with a crane! I've been on top of 4 unguyed sections -- well, guyed at 31, next guy set being installed at 62, so I was 8 feet down from the top of the 4th
For those who aren't aware of it, Dan is the proprietor of AN Wireless, which makes a line of towers that is directly competitive with Trylon. 73, Pete N4ZR Sometimes a tower is just a tower
Bill and Chuck are right, of course, but there is one important limitation on swing arms, the need for a gap in the middle of the boom equal to twice the face width of the tower. Thanks to W7NI for p