Description

EFHW 6-80 METER 34′ END FED HALF WAVE ANTENNA

The EFHW Alpha Jr is an end fed half wave HF antenna, nicknamed the JPole antenna due to the 2 parallel elements, is only 34 feet in length. This 6-80 Meter EFHW HF antenna enables coverage of major HF bands (6/10/12/15/17/20/40/80 Meters). You can even use a tuner to achieve a near perfect SWR on these bands, albeit with limited efficiency on 80 meters.

Weight: 1 pound
Configuration: End-fed configurable as Sloped or Horizontal
Frequency Coverage: 3.5-54 MHz (80-6 Meters)
Peak Power: 250 PEP SSB, 125 CW, or 25 watts for digital modes
Length: 34 Feet
Connector: UHF type SO-239

Analysis

Deployment Recommendations

For maximum effectiveness, keep your feed point as high as possible and run the antenna as a sloper for good NVIS and DX results, or a flat top for good NVIS results. An optimum installation would be where the antenna is deployed as a sloper with the high (feed point) end at 30 feet or higher and the low end at 10 feet or higher.

We do not recommend installing this EFHW end fed half wave HF antenna as a Vertical due to verticals being inherently prone to high noise (RFI) and unpredictable radiation patterns due to proximity of coax, which also allows for common mode feedback to increase.

For the initial installation, we do not recommend a Balun or air choke coil be used at the antenna. We recommend that you ground your tuner and rig. Your equipment has a ground bolt on the back of it, and manufacturers (and we at Alpha) do recommend a RF ground be connected on it to balance the circuit.  We only recommend that a RF Choke be used if you find one is needed, as would be the case if you hear feedback through speakers, etc. when you transmit. However, a Grounded Counterpoise would be the first option for any common mode current that might exist. If you find that common mode exists after you install the EFHW end fed half wave HF antenna, a Grounded Counterpoise wire can then be attached to the barrel connector at the antenna‘s feed point, which can be secured with a stainless steel hose clamp.

WA7KJ Customer Photo