This antenna is an excellent choice for a highly efficient, mid power (400w SSB) End Fed Half
Wave (EFHW) for your home QTH where you need an SO-239 coax connector.
The antenna is built using our in-house designed PCB, with double side tracks. We use a single Fair-Rite 2643251002 core, 56:1 winding, 3kv 100PF TDK capacitor and all stainless-steel components. The antenna is built to last.
We have attached SWR plots for the 80m-10m and 40m-10m version or the antenna. The graphs were measured at the transformer SO239 using a RigExpert AA230 Zoom, and a .05 wavelength counterpoise. Not at the end of a length of coax, which typically gives a lower SWR reading.
Select 80m version for 80m, 40m, 20m, 15, and 10m with no ATU. Although the SWR may be a little high on 80m at 2:1. You can also use the antenna on 30m, 17m and 12m bands, although you will need to use an ATU.
Select 40m band option to resonate on 40m, 20m, 15, and 10m with no ATU. You can also use the antenna on 30m, 17m and 12m bands, although you will need to use an ATU and we do not recommend using the 40m version on any other bands than 40m, 20m, 15m and 10m.
We can supply the antenna as a transformer only, or with 80m or 40m band antenna wire options.
We only supply this antenna with Kevlar military green wire. This wire does not stretch over time giving stable SWR measurements. Please bear this in mind, if you are using your own wire.
Our antenna wire comes with a six-turn compensation coil to pull down the higher bands.
Antenna details
• Custom PCB
• Transmit power rated at 400w SSB 100w CW/DATA
• Highly efficient 56:1 transformer, great option for the 15m to 10m bands
• Genuine single FAIR-RITE 2643251002 core
• SO239 Socket
• Heavy duty insulator
• All stainless-steel fittings
• Enclosed in an IP65 ABS GREY enclosure with a small hole in the bottom to help with any condensation
• Enclosure has several mounting points
• Optional 80m and 40m band military green Kevlar antenna wire, with 6 turn compensation coil.
This transformer uses a 2643251002 core which is highly efficient from 80m-10m at over 90% efficient at 10m band, 90+% from 80-20m. This has been measured using a NonoVNA with back-to-back transformers using our custom PCB.
Note
We supply antenna wire a little longer than needed. Therefore, you will need to trim the antenna wire to bring the antenna to resonance. We recommend taking 5cm snips at a time with some folded over.
Your SWR results may vary depending on the location of your antenna, its hight and orientation.
Always check your SWR before using any antenna. An SWR of more than 1.5:1 may damage your transceiver.