I am looking for one of the crossbows too or the super penetrator 500 gold ,both true .64 wave antennas. I am here in Alaska and I need all the gain and transmit possible. what was the max power input one can put into the crossbow? If you find one I will pay good money 4 one thanks again . 351 here in Anchorage , Alaska
After the ubiquitous quarter-wave vertical, the next most-popular vertical is a 5/8 wavelength vertical, which is almost twice as high.
5/8 is .625. If ".64" is the actual length that maximizes the gain, I confess I didn't know that. For an 11 Meter antenna, that's about a 6" difference, for an antenna whose radiator is otherwise about 21 feet high.
The 6 inch difference won't change the design of the matching coil (which is a necessary part at the base of the 5/8 wavelength vertical). The fine-tuning would be performed the same, whether the radiator has the extra 6 inches or not. Although the performance between .625 and .64 wavelengths could be calculated by a smart guy with a calculator, it would be difficult to notice in actual operating. If the difference in gain is some tenths of a dB, and an S-Unit equals 6 db, then the improvement in your signal going from a .625 radiator to a .64 radiator won't be noticeable.
Maybe commercial 5/8 wave verticals are actually cut for .64. I don't know. But I wouldn't worry about it.
The thing to worry about is if achieving the dream of a 5/8 wave vertical is possible. I say yes it is possible. Aside from the fact that there are certainly other fine 5/8 wavelength verticals available today, the design of the 5/8 wave vertical is textbook boilerplate, if you might get interested in building an antenna project. A blueprint with nothing but dimensions would be insufficient for a beginner -- an article with construction details would be important to build a strong antenna.
It's a big internet, and the plans have to be available out there someplace. Like I say, it's boilerplate, not top secret. Aluminum tubing is available on eBay and the closeout-hardware store. You might need a foot or two of heavy copper wire for the matching coil. And an SWR meter when it's all together to tap the coil just right.
In summary, although I'm sure the Crossbow was a thing of beauty (I never heard of it), don't get held up in achieving your 5/8 wave vertical just because you can't find a Crossbow. Make your own; it's not rocket science. There'll probably be a couple of mistakes made along the way, that's the "learning" part of the project. Your Version 2 will be better than Version 1.
When I was a kid, my father had a Mighty Magnum III, 5/8 wave vertical, until it got hit by lightning. He said he put a "Blitz Bug," which was a spark-gap lightning arrestor, in the coax. It was inline with the coax a couple of feet from the base of the antenna. The Blitz Bug had a screw-terminal, so you could run some aluminum ground wire from the screw-terminal to a ground rod underneath the antenna. But my father said he didn't have another piece of ground wire running from the antenna's mounting hardware to the ground rod, also. He said that if he had the mounting hardware grounded too, then maybe the Courier 23+ radio in the basement wouldn't have blown up, also.
Dad said the ground wire from the Blitz Bug to the ground rod had mostly vaporized. And inside the CB radio, there were wires going towards the SO-238 connector, but they were also vaporized, so there were no actual wires connected to the SO-238 anymore.
I remember that the coil connects the radiator to the ground plane. There are probably another couple of connections around the coil that I don't remember, but the DC resistance from the radiator to the ground plane is about 0 ohms, because of that coil. From a lightning-protection point of view, that's a good thing, since a ground wire run up to the mounting hardware and the radials will also provide a DC ground to the radiator. (That is, a DC ground, not an RF ground -- the coil provides a DC ground to the radiator, but it doesn't short out the RF.) And with the whole 5/8 wave vertical DC grounded, that means it's going to be real difficult to build up a static charge on any part of the antenna, and that will help keep from attracting lightning. It won't be a sure thing, but it will help.
In summary, 21 feet of aluminum rod sticking up into the sky is a thing of beauty, but you also have to read up on lightning protection if you're going to put up a vertical. Of course, disconnecting the antenna from the radio when you're not using it is an idea.
I was pretty much the only person that used that radio in those days. Another kid on CB. Good thing I didn't have my hands wrapped around the D-104 microphone when the lightning hit; heh heh.
Hi all. i tryed to buy a 27mhz or 11 meter .64 antenna i missed out buy about 6 months they dont make it any more it was a english made antenna called a VORTEX QUASAR .64 if you google VORTEX QUASAR .64 antenna there's a video of the .64 antenna they look strong and simple to make. it does not have a matching coil but it uses a length of cowax cable cut to a tune lenght with the outer and iner wire joined at the end. you would be best watch video for this to make sence. if i could fined a plan for a vortex quasar .64 antenna and a detail wireing of the cowax cable tuner i might make one. if you knew how to make a coil matcher you could use it. hasany body got a homebrew plans of a vortex quasar .64 antenna. john