Products Page
KQ6RH
(C) 1998, 1999, 2000
RFJ Communications Systems
(Up-Dated 2/20/2000)
Hubs:
In designing the antennas presented on our web pages, we found that several pieces of hardware were needed frequently for each of the designs. Most important was a strong but light weight hub that would accept the 1/2" fiber glass tubes. Our hub is machined from a solid 1" thick slab of black PVC that is UV resistant. This hub is slightly smaller than 6" on a side, and is drilled to accept four 1/2" spreaders. The center hole is drilled for a 1" mast or boom. These can be used either horizontally for planar beams or vertically as quad loops or cubic quads. These hubs weigh 1.75 lbs, but can be reduced by about 30% by drilling out excess PVC without seriously compromising the strength. We suggest this mostly for backpackers who need the lightest designs possible. All units come with stainless steel set screws. Two internal set screws lock the hub to the mast or boom. Each spreader is also locked in place with two set screws. The depth of the socket holes is carefully controlled so that the distance of the spreader tip from the central axis is increased by one inch. Thus, if an 8' 1/2" fiberglass tube is inserted, the tip will be at exactly 97" form the central axis.
Quad Hub shown with Mast or Boom and Two Half Inch Spreaders
HUB 4-050-100 Quad Hub $36 + shipping (shipping, assume 2 lbs each via UPS)
California residents add 8.25 % on all items.
Quad Guy Ties:
We also offer a quad Guy Tie. This is a nylon collar that slips over 3/4" or 1" tubing having four eye screws and a set screw for attaching guy lines. These can take 40 lbs of tension without breaking under static loading. Normally the monofilament line breaks first, and 40 lbs is well beyond any loading that can be imagined for these light weight structures. We initially offered only two models. So don't drill holes in you mast or boom that structurally weaken the tubing. ***By popular demand, we've added 1/4", 3/8" and 1/2" sizes that fit the 1/4", 3/8" and 1/2" fiber glass spreaders. These smaller sizes can be used to attach guys to the spreaders and can be used as wire guides for the antenna wire.***
Note, the price of our guy-ties is rather high because the machining is done by hand in low production quantities. If you would like to make your own guy-ties, the collars and eyebolts are available from McMaster-Carr. You will need a drill and tap for the threading size of the eyebolts. The 3/4" collars will not fit on the 3/4" tubing due to the oversize diameter of the tubing. Our 3/4" collars are machined to 25/1000" oversize so that they slip easily on the 3/4" tubing. If you require this size, you will have to find a machinist to bore collars. This is not an operation that you can do successfully with hand tools.
Nylon Guy Ring with 4 Attached Turnbuckles
GT 4-025 1/4" Guy Tie $8 + shipping (shipping, assume 1 oz each via UPS or US mail)
GT 4-037 3/8" Guy Tie $8 + shipping (shipping, assume 1 oz each via UPS or US mail)
GT 4-050 1/2" Guy Tie $9 + shipping (shipping, assume 2 oz each via UPS or US mail)
GT 4-075 3/4" Guy Tie $10 + shipping (shipping, assume 2 oz each via UPS or US mail)
GT 4-100 1.0" Guy Tie $12 + shipping (shipping, assume 3 oz each via UPS or US mail)
Each includes 4 eye bolts.
California residents add 8.25 % on all items.
Guides to High Performance Antennas
Extensively Updated (2/10/200)
Reflected M Antenna Guide:
The performance of the Reflected M antenna can be improved considerably over the version presented under Reflected M wire beams. The highly optimized design requires greater care in construction as well as a balun to match the driving impedance of 25 Ohms to the 50 Ohm characteristic impedance of most transceivers. This guide provides full information on performance, methods of optimizing, and more details for construction and assembly. We have developed a highly optimized guy configuration that significantly increases the rigidity of of the structure. So, now you can have a compact wire beam with a 20 dB F/B ration and better than 6 dBi gain.
Reflected M Guide $15 + $2 shipping
New!
Pfeiffer Cubic Quad Guide:
This guide gives the full details of how to design compact cubic quads based on the Pfeiffer linear loaded stub design. All versions of this antenna can be constructed with 8' spreaders or less. The guide contains the information for the electrical properties, feed properties, and the construction details using light weigh fiberglass components.
Pfeiffer Cubic Quad Guide $15 + $2 shipping
New!
Elevated Half Square Guide:
Get the extraordinary DX performance of the Half Square antenna with its low angle of radiation and high efficiency in a light weight portable design that can be rotated for selective coverage. This is a self supporting design that is very light weight (less than 6 lbs) and can be rotated with a low cost TV rotator. The antenna is bidirectional with roughly 3 dBi of gain, however, the launch angle over typical ground is about 10 degrees. This is a DX antenna that tends to reject local QRM by as much as 10 dB. Practical bands are 10, 12, and 15 meters.
Elevated Half Square Guide $10 + $2 shipping
California residents add 8.25 % on all items.
Address Inquires to:
R. F. Jurgens Communications Systems
4375 Ocean View Blvd.
Montrose, CA 91020
(818) 541-1452
e-mail rfjurgen@flash.net
New!
All of our products can now be ordered through MAX GAIN SYSTEMS
Max-Gain Systems, Inc., 221 Greencrest Ct., Marietta, GA 30068-3825
http://www.mgs4u.com/
For those who need materials to roll their own, most of our materials are purchased from McMaster-Carr and can be ordered directly on the internet.
McMaster-Carr, Inc., P.O. Box 54960, Los Angeles, CA 90054-0960, Ph: (562) 692-2932.
http://www.mcmaster.com/