DESCRIPTION - The GP-1 by Lance Johnson Engineering is a Cast Alumaloy Buss designed to improve the installation of Radials on an HF Vertical or Ground Plane Antenna. Alumaloy is a strong alloy comprised of 90 percent Aluminum and 10 percent Magnesium that is commonly used on Magnesium Wheels in the Automobile Industry. Sold primarily at the Dayton Hamvention for over 25 years Lance Johnson is pleased to offer the GP-1 by Mail Order. The GP-1 has been sold in 19 different DXCC Countries.
CHECK OUT THE NEW GP-1 WITH BULKHEAD - ADD $12.95 TO PRICE
FEATURES: The GP-1 features the following design elements:
· Rugged 1/4" Thick Construction
· 10" Diameter - Fits Inside Rohn 25-G Sections
· Two Dozen (24) Radial Tie Points
· Convenient Hole for PL-259 Connector
· Flange Mount Accepts 2" Diameter Mast - Perfect for Elevated Radials.
· Locking Fasteners (3) On Center Boss
PROUDLY MANUFACTURED IN THE UNITED STATES OF AMERICA
The GP-1 is suitable for both Ground and Elevated Vertical Installations. The GP-1 was reviewed in CQ Magazine in August of 1984 and is great for 4-Square Arrays. The GP-1 is very helpful on DXpeditions as it makes the installation of Radials very efficient.
PRICE INCLUDES SHIPPING IN U.S.A - VISA and MasterCard Accepted!
We will ship USA Customers a GP-1 direct for $44.95 and that includes your Priority Mail Postage! ORDER TODAY.
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BACKGROUND - While working on Ground Radials in 1979 in the middle of a field in Spring Hill, Kansas, Lance Johnson cut his leg with a razor knife. Sitting in the Emergency Room of the Olathe, Kansas Clinic, bleeding like a pig and receiving his stitches, he declared:
"There has to be a better way!" Work began a few days later on methods to attach radials to an HF Vertical.
DESIGN - After about a half dozen prototypes, a Larry Mills, WBØUXI, of Oak Grove, Missouri design was finalized and sale of the "Ground Plane One" was started in 1981.
USAGE - The GP-1 has been successfully employed for over 25 years with Trap Verticals and Single Band Verticals, with both Ground and Elevated Radials.
NEW GP-1 BULKHEAD ACCESSORY
Lance Johnson Engineering is pleased to offer the GP-1 Bulkhead. This is our legendary GP-1 that has a PL-259 style 2" Bulkhead for direct connection of Coaxial Cable. This bulkhead option can be added for an additional $12.95 at the time of the order. The position of the Bulkhead Connector is shown below - the Bulkhead is opposite the feed line hole of the GP-1.
BULKHEAD LOCATION - The Bulkhead is a accessory addition to the GP-1 as it provides a handy insertion point for Antenna Analyzers, Loading Devices or Basic Connection for Elevated Radials.
SIDE VIEW OF GP-1 BULKHEAD - This is a side view showing the 2" PL-259 style Bulkhead added to the GP-1. Notice the massive 1/4" Thickness of the GP-1. Yes, the GP-1 has been used in high power Commercial Applications! The Bulkhead surface of the GP-1 is milled and the connector is held in place with two large Hex Nuts. The fasteners are painted on both sides to provide improved weatherproofing.
EXAMPLE APPLICATION - Above is an example application for the Lance Johnson Engineering Bulkhead Connector using a 11 uh Coil for loading the Elevated Radials of a 160 Meter Vertical. By loading Elevated Radials the owner can reduce the footprint by 75 percent. In the 160 Meter case each radial would be 65.5 feet long instead of 131.0 feet long. The owner of this antenna has confirmed 213 DXCC Countries on 160 Meters from Colorado (DM79) using this design. A 131 foot long piece of #10 wire is used as the Radiator. The protective Plastic Bucket is available from Ace Hardware for $2.99.
INSTALLATION - The following general comments below will help you understand the installation of a GP-1. The GP-1 is also shipped with Installation Instructions that will assist you with your project.
1. Drainage - Dig a 3' x 3' square about six to eight inches deep at the base of your vertical and fill with gravel or decorative rock before you place the GP-1 and ground radials. This will eliminate the pooling of water at the base of your vertical and also reduce the growth of grass or weeds.
2. Oxidation - We recommend applying Petroleum Jelly to the top and bottom of the GP-1 fasteners as this will reduce the tendency for oxidation.
3. Wire Size - If you attach four ground radials to each GP-1 fastener you will yield 96 radials. In a situation like this wire size in not critical and #20-#17 is acceptable. If you are only using four elevated radials we recommend using solid #10-gage insulated copper wire to handle the current and the weight of the suspended wires.
4. Wire Length - Refer to the owners manual of your vertical regarding radial requirements. Elevated radials typically require a tuned 1/4 wavelength approach on a 1/4 wavelength antenna. For a base loaded trapped multi-band vertical you must have at least one elevated radial for each band being used. In a ground mounted cases exact radial length is not as critical.