Friday, March 27, 2015

End Fed Half Wave Antenna

I have found the End Fed Half Wave (EFHW) antenna to be the best all-around solution for portable operation. It is easy to deploy, requiring a single point of support.  If a support is not available I use the 31 ft Jackite fiberglass pole and a drive-on mount or alternatively dropped over a driven T-post.  These are truck camping alternatives only!  The hardware and tools are large and HEAVY but easy to use.

I have tried many of the well documented and the black-magic couplers and find little difference in performance.  I usually default to the coupler promoted by EARCHI (  It is easy to build, or you can support the club by purchasing it assembled.


In all cases a tuner is REQUIRED.  I use only Elecraft tuners, either internal to the rig or the T1 external tuner. I use RG174 coax exclusively and favor N-Type connectors, primarily for ease of assembly. If the coax is 25 ft or longer I have found that additional counterpoise is NOT required. I have used a Common Mode Current Choke near the operating position but have not identified any significant benefit at QRP power levels.  Fourteen turns of RG174 on 3 inch PVC provides approximately 1K Ohms at 7.040 mHz.  Simply drill 1/2 inch holes at each end of a 3 inch section of 3 inch PVC.  Carry this and a handful of tie wraps.  If you suspect RF on the feedline, simply wind the choke (without cutting the coax) and secure it with the tie wraps.

No comments:

Post a Comment