EndFedz EF-12QRP 12M End Fed Half Wave Antenna Instruction Manual

: June 10, 2024
: EndFedz

Table of Contents

EndFedz EF-12QRP 12M End Fed Half Wave Antenna
Product Information
22 AWG Poly Stealth.
Product Usage Instructions
PACKING LIST OF INCLUDED ITEMS
ASSEMBLY
SPECIFICATIONS
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

EndFedz EF-12QRP 12M End Fed Half Wave Antenna

ENDFEDZ ARE MONO-BAND ANTENNAS. USE ON BANDS OTHER THAN THE DESIGN BAND WILL RESULT IN SIGNIFICANT COAX RADIATION AND MAY RUIN THE MATCHBOX.

Product Information

The ENDFEDZ EF-12QRP is a 12-meter monoband, end-fed half-wave antenna. The package includes an EF-12QRP antenna, a PL-259 to BNC male adapter, an end insulator manufactured by Spiderbeam, a tuning stub, and this manual. The antenna is designed for use only on the 24.890-24.990 MHz band, and using it on other bands may result in significant coax radiation and could ruin the matchbox.

The antenna has a design Z of 50 Ohms and a V.S.W.R. bandwidth of 400 kHz at 1.5:1. It can handle up to 25 watts of SSB/CW power or 12.5 watts of digital power. The hardware is made of stainless steel, and the radiator is made of

22 AWG Poly Stealth.

For further information or assistance, contact Vibroplex LLC via phone at 865-309-5073 or email at vibroplex@vibroplex.com, or visit their website at www.vibroplex.com.

Product Usage Instructions

Unpack the included items and ensure that all parts are present.
Attach insulated lines to the end insulator for the least possible influence on the antenna. The antenna can be suspended horizontally, vertically, or sloping. For portable use, suspend the far end from a tree limb and let the matchbox hang just above the ground.
If using the antenna from a hotel room, hang the matchbox end just outside the window and let the far end hang, or preferably pull it away from the building with a guy attached to the end insulator.
Determine the overall length of the radiator and lace the wire. Tie off a support rope through the provided insulator once you are satisfied with the length.
Refer to Fig. 1 in the manual for some mounting ideas.

PACKING LIST OF INCLUDED ITEMS

EF-12QRP antenna
PL-259 to BNC male adapter (to use BNC-equipped coaxial cable if desired)
End insulator, manufacturer Spiderbeam
Tuning stub
This manual

ASSEMBLY

This antenna is essentially a half-wave dipole with one important difference– the feedline is at the end of the antenna.
In order to have the least possible influence on the antenna, insulated lines are recommended for attachment to the insulators. The antenna may be suspended horizontally, vertically, or sloping. Portable operation is easily accomplished by suspending the far end from a tree limb and letting the matchbox hang just above the ground.
The antenna has been used in hotel rooms by hanging the matchbox end just outside the window and letting the far end hang or preferably pulling it away from the building with a guy attached to the end insulator.
Tuning is best accomplished by using an antenna analyzer attached to the far end of the coaxial cable that will be used with the antenna. Once the initial resonant frequency is established, the antenna may be tuned just like a dipole. Shortening the far end by 1” will raise the resonant frequency by approximately 75 kHz. Trim or (better) fold the wire back on itself and wrap it to shorten the antenna. If too much wire is removed, the included tuning stub may be attached to the 10-32 stud at the matchbox end and trimmed to establish resonance to the desired frequency. Fine-tuning may be accomplished by changing the orientation of the stub with regard to the main radiator (I.e. rotating the stub and retightening the hardware. Tighten the hardware just enough to compress the lock washer.
Once you are satisfied with the overall length of the radiator, lace the wire and tie off a support rope through the provided insulator.
Fig 1 illustrates some mounting ideas.