ENDFEDZ EF-15QRP 15M End Fed Half Wave Antenna User Manual

: June 9, 2024
: EndFedz

Table of Contents

EF-15QRP 15M End Fed Half Wave Antenna
PACKING LIST OF INCLUDED ITEMS
ASSEMBLY
SPECIFICATIONS
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

EF-15QRP
15M END FED HALF WAVE ANTENNA
User Manual

EF-15QRP 15M 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

PACKING LIST OF INCLUDED ITEMS

EF-15QRP 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 from 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 approximately 75 kHz. Trim or (better) fold the wire ack on itself and wrap to shorten the antenna. If too much wire is removed, the included tuning stub may be attached to the 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 lockwasher.
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.

ENDFEDZ EF-15QRP 15M End Fed Half Wave Antenna - Fig1

EF-15 TYPICAL V.S.W.R. PLOT

SPECIFICATIONS

Polarity:	Depends on mounting configuration
Design Z:	50 Ohms
Frequency of Operation:	21.0-21.450 MHz
V.S.W.R. Bandwidth:	500 kHz 1.5:1
Power Handling:	25 watts SSB/CW, 12.5 watts digital
Weight:	4 ounces
Length:	22’3”
Hardware:	Stainless Steel
Connector:	Silver/Teflon SO-239, PL-259 to BNC male adapter included
Radiator:	#22 AWG Poly Stealth